Night Camera

It doesn't Bode well for the new flat...

2012-01-28T23:08:00.001-07:00

This latest test of correcting the collimation of the AT8RC demonstrates that it will produce a virtually coma-free image as seen in the image of M81 (Bode's galaxy) below. This is good! However, I screwed up on creating the new flat. My white sheet apparently got loose and I left the camera on high gain (1600 ISO) rather than 100 ISO where it was supposed to be. Doh. Before post-processing, the imaged flat was not what I was expecting. Ran the image workflow anyway just to see. Need to remake the flat.

I suspect though it may not help much as that even with a marginally imaged flat, the previous addition of the field flattener had significant impact on post-processing out the uneven signal levels due to optical curvature.

So, before reverting back to using the flattener lens, I will take another round using a deep sky filter for comparison.

Collimation step two...what step two?!

2012-01-26T00:30:00.001-07:00

Waited almost an hour for scope to cool down outside this evening. For the optical star test, all the provided extension rings needed to be added including a 2" eyepiece extension. Three-star aligned scope using the 1.5" insert and both a 15mm and illuminated reticle piece. Tracked on Sirius to conduct test. It is a wonderfully clear night, again.

Looked just fine. Nice round concentric circles. No warping as focused in and out. Pin point focus also provided sharp diffraction spikes across the entire field of view. Very nice.

Started taking shots of M81 without the field flattener. Have to say, the brighter image seen in the test shots was pleasing. No filter either, we'll consider this a test run on the new collimation.

Need to remember to not remove camera until after I've been able to create a new flat with this change to the optical configuration

AT8RC collimation, step one...

2012-01-22T13:40:00.000-07:00

There are some frightening online postings regarding attempts by other users to collimate the AT8RC telescope. Hmmm. This does not sound good. So, I dug out and read the manufacturer instructions. My takeaway? DO NOT mess with the primary mirror screws! Check. From my readings, those who have, managed to truly make it worse and then spent many hours, days, and other tools to get it back. This should be simple, why is everyone making it sound so hard?

The Astro-Tech collimation instructions emphasize use of a Chesire eyepiece with a light source. This kind of eyepiece has a mirror with a center hole, and the mirror is tilted precisely in a 45 degree angle such that you can visually inspect the appearance of concentric rings with an external light source. Well, my vision ain't what it used to be, so I used my Orion LaserMate Deluxe collimator which is a chesire piece with a laser as your external light source. Brilliant. Much better than my visual acuity.

Removed the extension rings and put the focuser assembly directly to the back of the scope. Turned on the laser collimator. Surprise! The secondary was not in collimation. The return beam point was off center by at least one of the LaserMate's target rings. Out comes the Allen wrench. Took a few minutes to figure out the "loosen-tighten" pattern on the secondary adjustment bolts, then fairly quickly centered beam point and tightened alignment screws. Cool.

Next step in collimation, the star test. Results will be in the next post.

Clear Skies!

Close-up On Rosette Nebula

2012-01-22T10:55:00.000-07:00

Near the center of the Rosette Nebula in the constellation Monoceros is an attractive open cluster. My daughter wanted another try at this deep sky object, after her first attempt a few years ago. I think we fared better this time, though still did not collect as many frames as we would have liked.

Nearly 400 frames from our new front driveway in the cul-de-sac. Given the amount of ambient light we had to deal with, I think it would be better to take this shot with a filter. Pushed post-processing on this one and added my own unsharp mask manually at the end.

Having second thoughts about continuing to use the field flattener. Why?! Well, the AT8RC is *supposed* to be largely coma free and the flattener is just another lense reducing transmission of photons in the optical chain. Was the field really that bad before? I don't recall. Maybe the RC scope needs colimation. When the image is finally processed, it is always cropped into my poster template. Wouldn't any aberrations in the outer field be removed? I recall images taken before the flattener were brighter. What about optical curvature? Well, calibrating each image frame with the flat takes care of that. Just need to create a new flat without the field flattener in place. Hmmmmm...haven't I been here before?

Unguided Beauty

2011-12-31T12:47:00.000-07:00

Incredible.

Noticed we had a surprising clear sky for once, even with a partial Moon approaching its first quarter in the Southwestern sky. Orion big and bold rising in the East, simply begged to photographed. Having little opportunity this year for much astrophotography, the prospect sounded wonderful to me.

Started snapping frames around 8pm, Moon set sometime after 11pm, and continued collecting frames until about 2am. Fantastic! A personal best, 458 unguided frames collected, just shy of 2 hours of effective exposure with the self-modified Canon 450D.

Actually, the nights activities produced over 500 frames, but after examing EACH one I had to throw out 50 due to undesirable motion effects...which is a bit on the high side. Not sure why. Temperature and slight wind maybe? Clumsy astrophotographer? Hmmm.

Wonderful thing about collecting more signal with the modified camera, the process provides more information to stretch out after the data fusion (preprocessing, aligning, stacking). A simple curve stretch after DDP processing and voila!

Filaments in black and white, Veil Nebula

2011-06-26T12:22:00.000-07:00

I don't usually post in black and white, but during post-processing I liked the look and feel of this.

A beautifully clear and dark evening afforded this fine take. Unlike star-forming emissive nebulae, the Veil Nebula is the diffuse remnants of a massive supernova. Dim nebula like this are difficult shots for a DSLR camera, even for a modified one as used in this photo. The image effectively comprises 75 minutes of exposure at ISO 1600. Something like this would make a great project over several nights to produce hours of exposure.

Technical bits: unguided, 300 x 15 sec. JPEG frames, 1600 ISO, modified Canon 450D, 200/200 bias/flat calibration, DDP post-processing, and slight color level adjustment. No stretching.

Hey! ...he's still alive.

2011-06-24T15:27:00.000-07:00

Well, this certainly has been a long drought.

After moving in December, I misplaced my camera battery charger. Things went downhill from there. Once in a while I would think to myself, "...where is that d*#m charger?" Similarly, without much nightly goings on nothing happened with the blog.

In short, just a lot of life changes at once, and another big project occupies my evening pursuit. Finally, found the infernal battery charger this past weekend, and last night I was presented with a beautifully clear dark sky. Put the other on hold and started shooting. Need to get updated flats and bias, but a new image should be due, shortly.

Hello!

Eagle Nebula with a friend...

2010-09-16T18:30:00.000-07:00

My good friend Carl came down and spent an evening (and part of the early morning) with me walking through the paces of setting up the telescope and camera. We had a fantastic dark night, timing couldn't have been better for Carl. We spent much of our time catching up on old times and what's new, but we were able to stay focused enough, pardon the pun, to get a couple shots in.

We chose the Eagle Nebula (M16) first, even though we new it had already passed the meridian and was headed downward toward the West. We still managed to capture a fine picture. I'll post our other shot of Alnitak and the Flame Nebula soon, just being lazy.

Bubble Nebula, NGC 7635

2010-09-05T16:45:00.000-07:00

One last dim target before the stormy weather sets in again. Happy to present this more improved shot of the "bubble", an emission nebula in the constellation of Cassiopeia located near star 4 Cassiopeiae and open cluster M52.

Unguided, 400 x 15 sec. JPEG frames, 100 minutes of accumulated exposure, 1600 ISO, calibrated and such, processed with DDP. No stretching.

Eye of God

2010-09-04T01:39:00.000-07:00

Nearly 400 exposures taken of the Helix Nebula in the constellation of Aquarius. This fascinating object is one of the closest planetary nebula to Earth, 700 light-years distant. I first heard of it on the Internet as the "Eye of God"...some silly news article. Had to check it out. Very dim, long exposures needed to detect that anything is there.

Unguided, 393 x 15 sec. JPEG frames, with DDP processing again. I've spent some time now using JPEG format to shorten and simplify the post processing. I think its given notable results. But, now that I've improved, it is probably time to work directly from RAW format. I'm sure I could do a much better job now with this new scope in pulling out detail.

...when things go wrong

2010-09-03T17:52:00.000-07:00

Not every shoot is easy. Things go awry, amiss, or just plain foobar. Below is an example of the Wrong Thing.

Yeah, so cool. Can you guess what the target might be? Bad tracking and a lack of attention to processing detail. Weeeee. This was supposed to have been a retake of the Trifid Nebula. Ahem.

First light with AT8RC

2010-09-03T17:25:00.001-07:00

First night out was a bit awkward, as my first target was cut short by some poor planning on my part. Had I realized before I started that the camera was going to travel right on into the tripod in just 100 or so frames, I would have just taken all the pictures on the other target. Honest, I wasn't drinking. Guess I was just a tad bit excited.

As such, 100 or so frames were certainly not enough to produce good results, but 200+ frames were just fine for a reshoot of the Pinwheel Galaxy, Messier 33 (M33).

Roughly half the diameter of our own Milky Way galaxy, M33 is a mere 3 million light years distant. Certainly nothing like "Five Million Years to Earth." This shoot was unguided, with 237 x 15 sec. JPEG frames, using a modified Canon 450D DSLR. Calibrated, stacked, DDP and unsharp mask applied using Nebulosity.

I love the improved magnification at prime focus with this scope...encourages me to go after some of the more smaller galaxies that I used to have second thoughts about.

Taking it to the next level with the AT8RC...

2010-08-23T21:29:00.000-07:00

It has arrived!

What a fine piece of Taiwanese machinery!

Balancing was quick and easy, using a recent replacement of the Atlas counterweight shaft with a 20" version from Criterion Machine Company of West Virginia. Replaced the stock focuser with my Moonlite version. The most excellent Moonlite focuser employs a shaft lock on the focuser knob rather than on the drawtube or drawtube rail, as compressing these induces unwanted image and focus shift. Had enough of that nonsense.

This week, evenings will be spent evaluating the back focus and adjusting the optical train configuration in preparation for the upcoming dark period. May the weather favor my intentions!

Countdown to September dark skies

2010-08-22T18:05:00.000-07:00

Nearing the end of the monsoon season with nine more days until the beginning of the next lunar dark cycle. Looking forward to good weather and clear skies!

Though the popular constellations for this period will be overhead, my attention will be a little to the east such that I can get sufficient exposures of deep sky objects throughout the evening. The regions of celestial interest in this September shoot being the constellations of Sagittarius, Capricornus, Pegasus, and Cygnus.

A new look!

2010-08-19T23:15:00.000-07:00

A little extra time on my hands; trying out the new eBlogger template designer. Nice. I like the change. Hope you do, too.

Messier 8, the Lagoon Nebula remix

2010-07-06T13:52:00.000-07:00

Okay, once again trying my hand at this beautiful deep sky object. Of all my shoots, this has seemed to be the most troublesome; my recent attempts thwarted by cloud pirates and processing gremlins. This time the odds are better with significant improvements:

polar alignment using setting circles and computed transit time
better dynamic range and less noise than previous DSLR
IR-cut filter removed
field flattener lens adapter
images normalized prior to stacking
new DDP algorithm rather than traditional "stretching"
nearly doubled the number of exposures taken

You be the judge. 300 x 15-sec. unguided JPEG frames, nearly 75 minutes of overall exposure, modified-Canon XTi, field flattener, calibrated, and processed with DDP.

Messier 23

2010-07-05T23:31:00.001-07:00

Back in Tucson under a beautiful night sky for the Fourth of July! Here is Messier 23, an open cluster in the constellation of Sagittarius; one more in my quest to capture every Messier object.

This is very close, cosmologically speaking, only a couple thousand light-years away and upwards of 20 light-years across. Taken with DSLR @ 1600 ISO, unguided, 190 x 15 sec. JPEG frames, calibrated 200/200 bias/flat, and finished processing without "stretching". Instead, out of curiosity, the Digital Development Processing (DDP) feature of Nebulosity was used.

From what I've read, DDP makes digital images more like film and was invented by Kunihiko Okano, a physicist and amateur astronomer. I compared my results with some manual stretching and found I preferred the DDP output. Threw in a some sharpening and color balance - voila.

Messier 82, Cigar Galaxy

2010-05-16T16:47:00.001-07:00

A new personal record, 400 frames! The whole lot taken in just under 5 hours during a good night of extended darkness. This galaxy gets its unusual shape from an exceptionally high rate of star formation, a process called starburst [wiki].

To add to this one's mystery, in April of this year, radio astronomers in Manchester reported a strange new object in M82. A 'micro quasar' was suggested, highly luminous and fairly stable. Some associate this with a massive black hole system, but not at the galaxy's center. The object is several arcseconds off center and an apparent motion of 4x the speed of light!

Yes, you read right, FOUR times the speed of light....warp speed, Scotty!

Casitas de Gila

2010-05-05T17:45:00.004-07:00

An astronomer's getaway, that's what it is. Many thanks to the proprietors, Michael and Becky, of this quiet mountain retreat just outside the small town of Gila, New Mexico. What a fantastic way to spend quality time with your telescope!

Large open areas to setup, easy access to power, and the basic comforts the casitas provide including refrigeration for your foodstuffs. If you choose to indulge in this experience, please plan to bring your perishables in with you as the nearest grocery is over an hour away. A small convenience store is 4 miles back in Gila...but that's it.

Arrived on Thursday the 29th and stayed through Saturday night May 1st. Though the timing wasn't so great for dark skies, the clouds and Moon were absent for a couple hours where I could try out my scope.

Decided to retake Messier 13, the Great Cluster in the constellation Hercules. Comparatively, I have to say even with only 152 unguided frames, the results of this location impressed me. Nestled in a location with a Bortle Dark-Sky rating of 2, we were somewhere around 6000ft. above sea level.

This photo is comprised of 152 x 15 sec. unguided JPEG frames at ISO 1600, taken with a modified Canon 450D and field flattener. Created new bias and flats for this outing, 200 apiece.

We'll be back here again soon!

M104 up close and personal...

2010-02-19T23:52:00.002-07:00

Jeepers, the Sombrero Galaxy doesn't look so bad for bumbling around with this big tube, fair atmospheric transparency, and then rolling clouds coming in to keep me to just 150 frames rather than the 250 frames planned. Unguided, 156 x 15 sec JPEG frames at 1600 ISO, noise reduction enabled, modified Canon Rebel XSi. Just stacked and stretched. Will try a little bias preprocessing to see if it helps a bit on the noise, I pushed this one pretty hard.

Bigger is better...

2010-02-18T05:42:00.002-07:00

Well, especially when it comes to telescope aperture. Decided to take
my 10" Dobsonian (Newtonian) optical tube and put it up on the Atlas
equatorial mount. A couple tube rings and Voila! Turns out I need a
little more weight to stay balanced, but once that problem is solved
we'll see if this monstrosity is up to the tracking challenge.

I'm excited to see what the impact to my unguided astrophotographs will be! All my shots to date have been with nothing larger than 6" aperture. Just need those counterweights...

Waiting on the weather...

2010-01-21T21:31:00.001-07:00

Wow, since after Thanksgiving the weather has really not played nice
with timing of dark nights. Just entering a bright Moon period, now.
Anxious for a break, this is the season for galactic clusters. Let's
go, let's go, let's go...

...the man in the Moon

2009-11-23T07:38:00.001-07:00

New MoonLite focuser rig

2009-11-21T21:13:00.003-07:00

The old Astro-Tech Crayford focuser that came with scope had issues when it came to keeping the drawtube square with the focusing assembly. Off-center position when locked down induced coma-like effects, made star alignment difficult, and fine focus was problematic. In short, it was just a cheap focuser.

Enter the new MoonLite focuser. In addition to being a solid piece of machined hardware, the primary benefit is that the drawtube is locked in position by applying pressure to the focusing shaft, not the drawtube itself.

Tried it out and focusing was a pleasure! Looking forward to using this from now on.

Camera mod successful!

2009-10-31T14:42:00.003-07:00

Yes!! I've done it, muwaaahaaahaahaaaaa! Below is a shot of the remnants from the offending filter...

Many thanks to Gary Honis and his great instructions from which I was able to successfully remove the IR cut filter from the Canon 450D in just under 3 hours. As I only intend to use this camera with telescopes, I decided to just remove it outright. If certain shots require some filtering, there are always premium front-mounted filters available.

Busy making new flats and master bias...next dark period is in a week or so.

Messier 35

2009-10-23T07:05:00.002-07:00

Filling another empty slot in my Messier portfolio, here is the open cluster M35. There is actually more stars to this as it spreads across an area almost the size of a full moon. Limited by my f/9 prime focus though, I kept the view centered on the bulk of the members.

Close Up on Alcyone, brightest of the Pleiades

2009-10-17T00:36:00.002-07:00

Since I don't have a focal reducer for the AT6RC, the f/9 focal length
gives a bit more magnification than with the Newt. The night was so
dark and clear, thought I'd try pick one of the lights in the Pleiades
before catching up on my sleep.

Wonderful stuff.

Unguided, 1600 ISO, 250 x 15 sec. JPEG frames, noise reduction enabled, with bias/flat calibration.

NGC 7789, one of the oldest open clusters

2009-10-17T00:33:00.002-07:00

1.6 billion years old, this cluster is one of the oldest.

Unguided, 1600 ISO, 225 x 15 sec. JPEG frames, noise reduction enabled, 250/173 bias/flat calibration.

Messier 103

2009-09-20T09:50:00.002-07:00

All right, back in the game! With cooler nights and cleaner workflow, its getting better. Here's a nice take of M103, the last I-am-not-a-comet object recorded by Charles Messier. Some 8,000 light years distant, Charles apparently never observed this open cluster. It was included in his work based on a report received by Pierre Mechain in 1781 of whom he became friends with in 1774.

Looks like it is time to collimate this RC scope, coma is apparent in the left and upper left bounds of the image. Gasp!

Messier 76, Little Dumbbell Nebula

2009-09-17T07:01:00.001-07:00

One of the faintest Messier Objects, a planetary nebula discovered in 1780 near the 4th magnitude star 51 Andromedae. 243 x 15 sec. JPEG frames at 1600 ISO, noise reduction, unguided, bias/flat calibrated.

Started taking this a little too early, as neighbor's outdoor lights came on and off a few times before going to bed. Some remnant remains. Shouldn't try starting before 9 or 10pm.

Messier 29, the "less impressive" cluster

2009-09-16T22:57:00.003-07:00

As quoted by the SEDS organization on its Messier Catalog site, "Messier 29 is a rather coarse and less impressive cluster."

Huh.

Kind of took that as a challenge, so I captured what I think is pleasing view of this simple open galactic cluster of blue giants, 7,200 light years distant. Charles thought enough of it in 1764 to write it down.

250 x 15 sec. JPEG frames at 1600 ISO, unguided. 250 bias, 173 flat calibration frames.

This image taken without field flattener and only flat/bias calibration. Rather than post-process dark frame calibration, the camera's built-in noise reduction (dark frame subtraction) was applied to each exposure, shortening the post-process time.

Creating a new master flat

2009-09-16T15:12:00.005-07:00

New camera, new master flat.

After crawling numerous blog and forum postings regarding flats, I never came across anything that really explained how simple creating a master flat calibration frame can be. After some personal research coupled with trial and error, I eventually understood the purpose of and how the calculation works. In addition, it became exceedingly clear to me that a common recommendation to point the telescope at various regions of the blue sky before twilight is collectively bad advice.

I want to correct this now!

What you want is a calibration image that will scale your pixels consistently to normalize individual pixel intensity - removing the variation in detected energy due to curved optical plane, the effect referred to as vignetting. Key phrase here, "scale your pixels consistently."

What does that mean? It means record a neutral image of your optical curvature. What does neutral mean in this context? It means without preference to any color channel (i.e., grayscale, folks). If you still don't get it, find a new hobby or just follow the instructions below and don't worry about it.

So, here's a simple recipe for creating flat calibration frames for DSLR prime focus astrophotography:

1) On a bright, sunny afternoon bring out your telescope and attach the camera exactly as you would for shooting
2) Ensure the camera is "focused", this will require some thinking on your part (suggestion: lock the focuser down from a prior night's shooting when the camera was focused on a star)
3) Tape a white sheet of paper without wrinkles across the opening of the telescope (see picture above)
4) Set the camera to aperture-priority mode and ISO 100 (best dynamic range/low noise), this will record our "white" light in the median range of the combined color channels - forming our grayscale image. Afterwards, look at the histogram readings from the images and you'll see what I mean.
5) Take as many shots as you can, I strongly recommend over 100 to get good saturation and signal coverage. This shoot I'm taking 250 as I tend to go for 200+ image frames on any good outing.
6) Once you've collected them, use your favorite stacking program to apply a standard distribution.

You'll also want to adjust the RGB channel offsets, so they are right on top of each other (this is a one-click operation in Nebulosity called Adjust Color Background). This will account for the slight fluctuations of the channels we recorded and then you'll have your wonderfully neutral master flat!

Good luck!

Canon T1i mod gone bad...

2009-09-10T19:27:00.002-07:00

Well, attempted to mod the T1i by removing the IR cut filter. Got into the point of removing the sensor plate, only to discover some special torque screws (for which I have nothing to get them out). Put it back together, apparently a little too quickly, only to discover that it will no longer take a picture - "temperature too high." Great. Something is shorted...could be one of a hundred contacts that were involved in various ribbon cables or even the aluminum shield plate.

When I have more time, and patience, I'll look into trying to bring it back. For now, I've decided to continue the DSLR path and when convenient, pay someone to do the mod. A new Rebel XSi has arrived, a couple hundred cheaper than the T1i, lighter and less noise (see previous post).

Cheers!

Noise and more noise

2009-09-01T20:41:00.002-07:00

After a few months of taking additional photos with the new Rebel T1i (500D) DSLR camera at various high speed settings, there really has not been any improvement in eliminating high end noise as compared to the early generation Canon Rebel XT. In fact, after some comparative study of detailed reviews carried out by professional camera webzines, the T1i fares slightly worse than the model its intended to replace, the Rebel XS (450D). And my test photos support this, too.

The good news is that noise reduction modes at ISO 1600 perform comparably with the 450D.

It is not a complete loss. Where the Rebel XT was an 8 mega-pixel camera, the T1i is 15!! Longer battery life, and more importantly no battery amp glow!! There is still much I would like to accomplish with DSLR astrophotography. In the near term, I am looking forward to eventually replacing the IR cut filter with a wider band version designed for deeper reds and extended UV.

Messier 30

2009-08-16T00:14:00.005-07:00

Back at it...a couple great dark nights are upon us! Here we have another in the Messier marathon series, M30, a globular cluster in the constellation Capricornus. This will be the last photo taken at 12,800 ISO setting for a while. Even though much has been removed from the shot, the noise is a bit excessive. Taking this last super high gain shot also allowed me to test my flat I created.

Worked great. Vignetting go bye-bye.

This unguided photo taken with the Canon T1i as 104 x 15 second JPEG frames, long exposure and high ISO noise reduction enabled, and calibrated with 200 bias, 100 dark, and 200 flat subs.

Below is my exciting new flat used in the calibrating the photo above. Created it by placing the telescope under the patio in this bright Arizona afternoon sun and taping a white sheet of paper across the telescope opening. Made sure the sunlight was indirect and bright across the entire surface of the paper. Set the Canon into AV exposure mode and ISO 100, proceeded to collect 200 frames!

After calibrating with bias, the frames were stacked together creating this master flat. The histogram in the camera showed it nailed dead center and the red, green, and blue curves aligned right on top of each other. Don't think I could get it any closer to grey than that!

IC 4665

2009-07-28T21:31:00.001-07:00

A break in the weather and finally able to test out my workflow changes. Turns out the camera built-in noise reduction really needs to be enabled for this kind of photography. In this case, both long exposure (dark frame subtraction) and a new enhanced high ISO speed noise reduction is enabled. Successfully eliminated the mysterious banding I was seeing in post-processing.

This image was taken with 180 x 15 sec. JPEG frames at 3200 ISO, field flattener, strong noise reduction, and of course, unguided.

So much for the TI-89

2009-07-25T21:19:00.003-07:00

Apparently, the data I/O output signal has been changed in the TI-89. Frequently, an extra "pulse" is detected by the camera. This utterly screws up the whole mirror lock up routine. Without putting a scope on it, I suspect the TTL level changes are not as long as in the older TI-83 model. Guess I'll keep the TI-83 and give up the shiny new TI-89.

Monsoon Season is upon us...

2009-06-28T22:25:00.007-07:00

Well, so much for stargazing...can at least enjoy the evening light show when the storms roll through. In the meantime, I will be preparing for the next outing. A new TI-89 programmable calculator is on order, and this one includes a real-time clock for more accurate shutter control timing. This will consume a little extra time to revise my ASTROTMR TI-BASIC program with improved settings.

A short focuser extension tube and a Lumicon broadband filter are also on order. The short extension tube should permit me to put the diagonal back in, now that I'm committed to using the field flattener in my astrophotography. The broadband filter will help reduce the additional sky glow, especially when imaging more toward that part of the sky with the Tucson "light dome."

Since I've made progress using the field flattener and corrected my process to create darks and bias frames, thinking about going all the way and experimenting again with 12,800 ASA! I've already taken 100 bias frames set at that speed. Will plan on taking 100 darks at this extreme when the next clear night arrives and maybe shoot for the Lagoon Nebula, again. Pretty exciting stuff!

47 Messier objects and counting...

2009-06-22T19:39:00.001-07:00

...only 62 to go.

Messier 21

2009-06-22T19:14:00.001-07:00

Yep, I think I've definitely hit the sweet spot with this new camera and RCT configuration. The field flattener delivers. The open cluster M21 here, 180 x 15 sec. JPEG frames, 3200 ASA, Astro-Tech Field Flattener, calibrated with 100 bias and 100 darks.

Messier 19

2009-06-22T19:10:00.001-07:00

The globular cluster M19 here, 180 x 15 sec. JPEG frames, 3200 ASA, Astro-Tech Field Flattener, calibrated with 100 bias and 100 darks. Note, additional noise reduction not enabled, standard DSLR picture settings.

Vignetting resolved!

2009-06-22T18:54:00.002-07:00

Introducing the new 2" field flattener from Astronomy Technologies. Designed originally for use with refractors, it appears to work extremely well with a Ritchey-Chretien telescope, too. Last night I used it in taking both M19 and M21, and I am very pleased with the results! The impact on the uneven distribution of light (vignetting) across the image has been dramatically reduced, to the point any negligible artifacts are easily stretched away.

Unfortunately, I lose my forever focus as it requires I remove the diagonal and add a 2" extension. I'll see about ordering a 1" extension and putting the diagonal back - the diagonal makes for a more comfortable viewing position of the camera LCD image display.

M11 and M18

2009-06-18T07:18:00.003-07:00

Seized upon a great dark night and grabbed these two shots of Messier objects 11 and 18, both open clusters. Messier 11 is known as the Wild Duck Cluster. I understand the bright stars appear to form a triangle like a flight of geese, but..um...I don't see it.

Worked on my image processing some, and in these shots all additional noise reduction on the Rebel T1i was turned off. Camera brightness, contrast, sharpness, and saturation levels were all in standard settings. As such, I took 100 darks and 100 bias frames to perform image calibration during post-processing. This time I did bias correctly by setting camera to the shortest shutter speed, 1/4000. No flats this time, that's for another blog entry.

The following picture of M11 comprises 180 x 15 sec. JPEG frames at 3200 ASA, calibrated with 100 bias frames. Stacked and stretched.

This lovely shot of M18 is 1800 x 15 sec. JPEG frames at 3200 ASA, calibrated with 100 bias and 100 dark frames.

M22 and M57

2009-06-03T19:22:00.002-07:00

Here are the last two shots taken in May, the lovely M22 (one of the largest globular clusters in our galaxy) and a retake of M57. The last time, M57 was taken I used a 2x Barlow lens and, of course, it magnified all my fine errors. Interesting that this time using an f/9 telescope, the 15 megapixel DSLR can capture M57 at the same equivalent magnification and resolution as was with the Barlow on the 6" f/5 Newt. Well, I guess that makes sense, f/5 x 2 = f/10. Both these images were unguided, 180 x 15 sec JPEG frames, 3200 ASA, with noise reduction enabled.

See ya' in a couple more weeks.

Wrapping up...

2009-06-01T00:55:00.003-07:00

This dark period is almost over, and the night is wonderfully clear. Here are a couple photos of the new gear in action! Alignment was spot on tonight, tracking extremely well. I have to admit, using the calculated transit for Polaris really makes unguided work painless. Was really waiting for the Moon to go down so I could get one last shot in, M22. So, while we were waiting I went ahead and took 180 frames of M57, the Ring Nebula. Should be interesting to see if the baffling makes any difference in the moonlight.

I'll never have to focus again...

2009-05-31T17:27:00.003-07:00

In trying out my new quartz dielectric diagonal this weekend with my AT6RC, not only did I have to remove both 2" extensions, but with the focuser dialed all the way in and locked down...my camera was in perfect focus! It seems to me that if the diagonal is simply a reflection plane at 90 degrees, then this must be all about the AT Ritchey-Chretien telescope design. Amazing. I've sent an email off to Astronomics to see if they or the manufacturer know if this was intentional.

I've attached a picture below if you're not sure what I'm talking about.

Messier 12 and 25

2009-05-31T16:18:00.002-07:00

Okay, so 12,800 ASA was a bit over the top. I've settled down now, 3200 ASA with this new camera will work just fine and reduce some of the time it takes to collect the images. It appears that 180 frames would be a good goal for a DSO, giving me more exposure time in less time than the Rebel XT at 1600 ASA.

Here we have a fine globular cluster M12 and a bright open cluster M25. M12 would have had more frames, but I bumped into the mount (wandering around in the dark) and caused the subsequent images to shift over 30 arcminutes. Pooh.

Messier 9 and 10

2009-05-30T18:09:00.005-07:00

Both globular clusters shots, unguided 30 x 15 sec. JPEG frames at 12,800 ASA, noise reduction enabled. Roughly 7.5 minutes of exposure time.

With just a few more Messier shots, I will have the first 20 Messier objects captured! ...just another 60 or so to go.

New Camera and Messier 8, the Lagoon Nebula

2009-05-30T17:39:00.004-07:00

The Canon Rebel T1i DSLR camera just arrived and I've been checking it out. The camera is capable of 12,800 ASA and even boasts double the pixel density from my Rebel XT! It now takes only 20 minutes to collect the same amount of unguided exposure it would normally take me 3 hours to collect, still using 15 second frames. Clearly, noise processing is different but my initial results seem very pleasing.

So, here is the Lagoon Nebula taken with the new Ritchey-Chretien telescope and camera.

Oh yeah, no amp glow either!! That's a relief.

Messier 6

2009-05-26T10:19:00.003-07:00

Well, its getting better. This shot of M6 was taken with 243 x 15 second JPEG exposures, 1600 ASA, approximately 60 minutes of exposure. I've created a new border template for the images, too. Getting easier to align the scope, and tracking was good. Now, I need to start learning about vignetting, something I didn't have to deal with on the Newt.

Messier 14

2009-05-25T16:06:00.004-07:00

Unguided 193 x 15 second frames, 1600 ASA. This globular cluster includes numerous variable stars, there was even a Nova here in 1938.

Had trouble with clouds during this shot, not as bright as would like, but it is 2 orders of magnitude less bright than M2.

Messier 2

2009-05-25T16:00:00.002-07:00

Unguided 72 x 15 second frames, 1600 ASA, noise reduction enabled, stacked and stretched. This a photo of the globular cluster M2, one of the largest. This object is 37,500 light years away and comprises approximately 150,000 stars!

Always make sure the batteries are charged

2009-05-25T13:18:00.002-07:00

Forgot to charge my second battery. Arrg. After waiting for it to recharge, my second shoot of the night (early morning) of M2 captured only 72 exposures before daylight crept in.

Photo shoot commencing...

2009-05-24T22:49:00.001-07:00

Cloud cover finally cleared my target area, calculator kicked off for 250 takes. Again, I hope the clouds stay away.

Second night out

2009-05-24T21:38:00.002-07:00

Alright. Everything is tightened down, now. No rotating. No tension on any of the wired connections. No motion sickness tonight.

3-star alignment went well. Zeroed in precisely on Antares right afterward, centered in the crosshairs. Focusing proceeded quickly, 2 minutes this time. I also took the time to align the new 60mm piggybacked refractor. What an excellent short scope, the view was crystal clear with excellent contrast. I viewed M57 with both a 25mm high quality Plossl and one of my wide-view 5mm eyepieces. Fantastic.

I'm pursuing M14 tonight. Waiting for a few clouds to dissipate. Hope they stay away.

Setting up...

2009-05-24T21:26:00.002-07:00

Well, attempted shooting Messier 3 last night with limited success. Dark night, mostly clear. It's been six months since my last outing...a little out of practice, I guess. Focusing took quite some time, as I soon learned to take shorter bright star exposures to focus on the diffraction lines. The visual acuity of this RC scope is impressive. It turns out that only a few 3-second 1600 ASA exposures is all that is needed to perform LCD-review focusing. Now I know.

Tried to get 250 frames, but could only use 147. Something else I learned is to make sure the heavy duty Crayford focuser is securely tightened. The focuser unit on this RC scope can be rotated 360 degrees at your pleasure, unless its not fully tightened then it rotates on its own. I also found that I had not made sure the camera 2" extension was tightened. It was loose, too. Sooooo, the meandering image began with exposure number 148, and continued to do with the rest of the exposures - watch the bouncing ball.

Below is the not so impressive image of M3 taken with only 147 exposures.

First trial photo...

2009-05-23T01:06:00.003-07:00

Here is a 30-second shot at 1600 ASA of Arcturus, this time no noise reduction enabled, and parameter settings cleared. In getting into focus, it struck me how crisp the diffraction lines were - like sabers. This is likely not perfect focus as the visual acuity of this new scope clearly exceeds the limits of my 8 MP camera. When they say the AT6RC is an astrograph, they're not kidding. Be forewarned, the AT6RC is not intended for visual observing. Both of the 2" extensions were necessary to achieve prime focus with the DSLR. Evaluating image with eyepiece required a barlow and extension...looked like a damn microscope mounted on the back of the telescope. Very glad I added the 60mm short, great for viewing and with a 2" compression adapter I'll play with the camera use on it, too.

After this I took several 30-second shots of M4 before clouds set in, so I could get some feel as to overall improvement on a short collection of exposures. Found that stars were consistently spherical. Still picked up perceptible tracking error at 30 seconds (expected), and I did notice coma in the lower left and part of lower center in the overall image. This suggests I need to check collimation. The coma is certainly no where near as bad as on the Newt. I'm really just being nit picky. The image is excellent.

Unfortunately, my attention was diverted by the increased amp glow captured in so little frames. Yikes. I mentioned in prior posts the increasing strength of the glow. It would seem reasonable to deduce that over time taking the length of exposures required for astrophotography are pushing the limits of this camera design. The battery unit and power supply are just too close and the sensor is not well isolated from the energy produced - the amp glow is "burning in" to the sensor.

For the record, this is the 10,152nd exposure taken with the Rebel XT. Guess, it is time for a new camera. Supposedly, the new Rebel designs have improved noise reduction and have eliminated amp glow. Therefore, I should get considerably much more life out of a new camera. The XT will work just fine consigned to normal day photography, and I have a lovely lens kit for it.

A little pricey, but I've decided to purchase the new Rebel T1i (body-only of, course). It jumps two generations in DIGIC processor technology, almost doubles the image density to 15.1 megapixels, doubles my gain to 3200 ASA, and includes HD movie capture. Curiously, the movie capture mode suggests I could take planetary images like the current webcam craze...with way better resolution.

Ok. I done spending money, now.

The New Telescope is Ready!!

2009-05-21T23:55:00.005-07:00

Excellent! Here are some pics of the new rig. We shall have a wake in honor of my venerable $380 6" Newt, for it served me well. I'll try to keep it in safe storage, as I expect my young daughter will be very interested to use it.

Check out the extensions I had to add for prime focus.

New telescope on the way...and it is not the Vixen

2009-05-17T22:38:00.010-07:00

Sorry, Vixen. Astronomy Technologies new line of Ritchey-Chretien astrographs has you beat! I placed my order tonight for the AT6RC from Astronomy Technologies along with a 66mm short tube refractor (sporting a 2" Crayford focuser) as another photographic platform.

The AT6RC is 6" f/9 true RC hyperbolic mirror design, with 1/12th wave BK-7 mirrors, and enhanced aluminum coatings for 96% transmissivity. Like the Vixen VC200L, the AT6RC mirrors are fixed, and focusing is external. Unlike the VC200L, this new RC scope is a true reflector, no optical lenses. For another $600 I could have gone for the larger 8" RC with dialectric coatings for 99%, but just couldn't bring myself to do it.

Should have some great experiences with this!

I'm back...

2009-05-16T14:54:00.002-07:00

Alrighty. After several months away dealing with life, I'm ready to kick off some nightly astronomical activities.

The telescope mount has been realigned, camera batteries charged and cooled, and I've upgraded to Nebulosity 2.

The dark sky is upon us, and I'm just waiting for the clouds to clear...

Messier 47

2008-12-30T12:52:00.002-07:00

The open cluster M47 is approximately 1600 light-years from Earth and is 78 million years old.

Unguided, 250 x 15 sec JPEG frames, 1600 ASA, noise reduction enabled.

NGC 2264, Christmas Tree Cluster

2008-12-30T12:44:00.002-07:00

Here is the Christmas Tree Cluster (the bright star forms the base of the trunk) and the brighter portion of the Cone Nebula. Much more exists in the IR spectrum. This would be a good subject for a CCD or modified DSLR.

Unguided, 200 x 15 sec JPEG frames, 1600 ASA, noise reduction enabled.

Messier 36, another revisit

2008-12-24T18:16:00.002-07:00

Another improved image, unguided, 117 x 15 sec JPEG frames (threw out 50 frames because I just couldn't get the neighbors Christmas light glow out...they were on a timer, and shut off about an hour later), 1600 ASA, noise reduction enabled.

M42 Orion Nebula, revisited

2008-12-24T13:56:00.002-07:00

One year ago, I made my first telescope purchase in years, a 6" inch Newtonian and an Atlas mount. Bought a DSLR camera, too. I desired to learn about digital astrophotography. As the year progressed, I found myself in a relentless pursuit of simplicity. I could have taken the high road and gone with much more expensive CCD technology and computer-based control and processing, but it just did not seem worth the expense.

Taking an approach similar to radio astronomy, short samples at high gain, has been as rewarding as I could have ever wanted. Without so much emphasis on technology, I find I'm enjoying my study of the heavens, telescopes, and astronomy just as much as I did in high school.

So in tribute, here is an unguided retake of Orion nebula, one year later.

Unguided, 176 x 15 sec JPEG frames, 1600 ASA, and noise reduction enabled.

NGC 2024, Flame Nebula

2008-10-26T18:26:00.002-07:00

Unguided, 272 x 15 sec JPEG frames, 1600 ASA, and noise reduction enabled. Had a little trouble getting this one, but in the end it didn't turn out too bad. I appear to be having battery amp glow issues as of late. Not too sure what that's all about. Nights have been getting cooler, too. Strange. It has been more prominent lately. Thinking about charging ahead of time and letting the batteries refrigerate for a bit.

Eric, "supersize" has been restored

2008-10-24T19:35:00.004-07:00

The friendly folks at Google recently made a change to Picasa regarding the embedded picture hotlinks. Currently, the embedded references constrain you to a few fixed viewing sizes and does not directly provide a link to the full-size JPEG that is stored there...like I used to be able to get.

I figured out how to bypass this. If you happen to notice the new links Picasa uses now, you'll find a size code inserted in the URL pathname. For example, the 288 pixel-wide view includes .../s288/... in the pathname. If you instead use .../s0/... for size zero, then apparently it defaults it to the full-size image stored there!

Programmers are so predictable.

So, all the 9 embedded links since that change in the Messier and NGC collections sidebar have been supersized, and I'll do so for all new pics.

Cheers, Eric. Thanks for letting me know you liked that feature.

Messier 1, Crab Nebula

2008-10-24T18:13:00.002-07:00

Unguided 251 x 15 sec JPEG frames, 1600 ASA, noise reduction enabled. Always wanted to get a snapshot of this. Could stand to be taken at higher magnification.

Messier 15

2008-10-24T18:12:00.002-07:00

Unguided, 212 x 15 sec JPEG frames, 1600 ASA, noise reduction enabled. This globular cluster and the stars around it bare a close resemblance to the view of M13 in Hercules.

My next telescope...

2008-10-21T14:54:00.005-07:00

This hybrid Cassegrain design from Vixen is awesome. The VC200L uses a sixth order aspherical primary mirror and a convex secondary mirror, replacing the meniscus corrector plate with a triplet corrector lens near the end of the optical chain. Focusing is performed using a 2" Crayford focuser at the end of the optical chain, rather than moving the primary mirror and suffering mirror shifts during focus. The optical tube is baffled and the secondary is oversized. At f/9.5 it is somewhat faster than traditional Cassegrains.

For $1700, it is certainly more pricey than my $380 Newtonian. Yet, the step in optical precision is significant, and comparatively well-priced against competing and mainstream high-end designs.

Of all the optical systems I've researched, Vixen's VISAC design is the only one that addresses spherical aberration, coma aberration, and field curvature. Even chromatic aberration is far less than the exceptional (and more exceptionally expensive) flourite lens refractors. Considering that field curvature is eliminated, suggests better optical correction than even a Ritchey-Chretien...and new manufacturing methods for RC scopes are producing some much less expensive designs

From what I've read and observed from vendors and blogs, I think the VISAC design hasn't caught on simply due to technical arrogance in much of the user base and limited marketing visibility. It just isn't sexy enough and there simply are not any additional distractions or operational steps to get in your way. But, as of today, you can buy them from Orion Telescopes online!

Eliminating the corrector plate and complex mirror focusing mechanism clearly helps reduce the manufacturing costs. Baffling and Crayford mechanisms are cheap. So, the cost is likely rolled up into the improved mirror coatings and the corrector lens. A fair trade, I'd say.

All my deep sky photography relies on the reflectivity of my 6" primary mirror and oversized secondary without any loss in light transmission due to an intermediate lens configuration, though my reflectivity is somewhere in the mid 90% range (it's less than $400 bucks what do you expect). So in my view, the VC200L decrease in transmissivity by adding a triplet lens is offset by the 1.8" larger aperture and higher reflectivity from the superior Japanese mirror coatings.

Don't just take my word for it, read this article by Astronomy Technology Today. Note, the article is taken from Vixen's web site as access online requires subscriber login.
...now I just need to save my pennies.

Messier 34

2008-10-21T07:22:00.007-07:00

Unguided, 208 x 15 sec JPEG frames, 1600 ASA, noise reduction enabled.

Messier 52

2008-10-21T07:22:00.005-07:00

Unguided, 223 x 15 sec JPEG frames, 1600 ASA, noise reduction enabled. Nice clear and dark night. Open cluster in Cassiopeia, discovered by Charles Messier in 1774. Even caught a glimpse of the Bubble Nebula near the upper left.

Baader Coma Corrector and the Sculptor Galaxy

2008-10-06T22:21:00.002-07:00

Unguided, 247 x 15 second JPEG frames, 1600 ASA, with noise reduction. The camera was also fitted with a Multi-Purpose Coma Corrector (MPCC) from Baader Planetarium, Germany.

The MPCC attaches to the T-ring right in front of the camera, and comprises what appears to be 2 lenses complete with 7 layer coatings to provide a completely flat field and eliminate coma from the fringes of the field of view.

Well, I've definitely observed an elimination of coma around the edges of the larger master photograph (all my images are cropped to scale to a widescreen display). But, any time a lens is introduced less light makes it through, and two or three elements (lenses) has some impact. You can see in the image that the diffraction lines are barely visible and the stars less point-like.

Another unexpected downside due to the proximity of the MPCC lens surface to the CMOS sensor, is the radiated energy from the active CMOS sensor electronics in the camera being reflected right back onto the sensor! Arrrgh, this adds more noise the point it interferes with getting a cleaner image. I've taken several other photos so far with and without the MPCC, and the additional reflected noise is consistent. Never occurred to me before I bought the thing.

Its my opinion at this point, dealing with coma means spending more for a higher quality instrument such as a Mak-Newt, SCT, or of course an RC telescope. There is a hybrid made by Vixen, the VC200L, where the front plate is removed and a 3 element corrector optic is placed at the end of the focuser assembly. Comparable light loss might be mitigated by the fact it has an 8" aperture rather than 6" in my scope. Its possible the VC200L lens surface is far enough from the camera's CMOS sensor (at least 3 or 4 inches) that it might reflect very little back.

Messier 39

2008-09-25T21:33:00.002-07:00

This open star cluster is approximately 800 light years away and estimated to be from 200 to 300 million years old.

Unguided, 200 x 15 second JPEG frames, 1600 ASA, with noise reduction enabled.

Galaxy and Cluster, NGC 6946 and NGC 6939

2008-09-25T21:19:00.002-07:00

An interesting view, here a nearby spiral galaxy, NGC 6946, highly obscured by interstellar matter of our own galaxy is contrasted in this photograph by a distant open cluster, NGC 6939, in the same field of view.

Since 1917, eight supernovae have been observed in NGC 6946.

Unguided, 204 x 15 second JPEG frames, 1600 ASA, with noise reduction enabled.

NGC 7293, Helix Nebula

2008-09-25T20:52:00.005-07:00

Tried a difficult target, the Helix Nebula, a large planetary nebula. Given that it is one of the closest of such nebula to our solar system, you would think it was much more distant. Apparent brightness is spread across a vast surface relegating any other observing details deeper in the IR range. Clearly, photographing this kind of deep sky object approaches the limits of what can be reasonably done in an evening with the latest DSLR camera.

It is possible another alternative might work, taking successive exposures over several evenings. I have yet to try this. Maybe if I have time during Christmas break. Would really need to leave the telescope outside and in place for a whole week.

Unguided, 250 x 15 second JPEG frames, 1600 ASA, with noise reduction enabled.

Messier 27, Dumbbell Nebula

2008-09-06T16:06:00.002-07:00

Yes, Dumbbell here was the first planetary nebula to be discovered, and resides in the faint northern constellation of Vulpecula. The central star is a white dwarf, larger than any known white dwarf. In 1970, astrophysicists found the nebula around the star was expanding at 31 km per second, suggesting an age of only 9,800 years!

Unguided, 202 x 15 second JPEG frames, roughly 51 minutes of exposure, 1600 ASA, noise reduction enabled. Just stacked and stretched, great natural color and contrast. The images were taken between the hours of 10:30pm and 1:00am in the morning. The prior blog entry regarding M33 was taken afterwards until about 3:30am in the morning. The M33 shot is much more grainy, given largely to being in the portion of the sky over the Tucson light dome. In the future, I should probably avoid imaging toward the West and Southwest portions of the night sky.

Messier 33, Triangulum Galaxy

2008-09-06T15:10:00.002-07:00

Unguided, 203 x 15 second JPEG frames, roughly 51 minutes of exposure, 1600 ASA, with noise reduction enabled.

This was a fairly dim object, even though it is listed at about magnitude 7. Could stand to get twice as many exposures to bring out more detail. Still, a really spectacular face-on spiral galaxy. It has also been referred to as the Pinwheel Galaxy, even though Messier 101 is officially recorded with that name.

Messier 45, Pleiades

2008-09-05T19:17:00.002-07:00

At last, another chance to try the Pleiades now that I have had much more practice. This image is comprised of 288 x 15 second JPEG frames, unguided, 1600 ASA, approximately 72 minutes of exposure! A personal record.

This cluster is number 45 on Charles Messier's list of nebulous objects. This beautiful cluster of stars was also mentioned by Homer around 750 B.C.. It has had many names, including Seven Sisters, Matariki (New Zealand), and Subaru (Japan). Comprised of hot blue stars formed over the last 100 million years, the brightest stars illuminate ancient dust collected from the original formation of stars giving it the bluish nebulosity.

IC 5146, Cocoon Nebula

2008-09-05T08:50:00.002-07:00

Well, here's a tough one. Unguided, 180 x 15 second frames, 1600 ASA.

The Cocoon Nebula is an emission, reflection, and absorption nebula all woven together in a young developing star cluster. Formed only 100,000 years ago and is 4,000 ly from Earth, fairly close in astronomical terms. What makes this interesting is the dark nebula you can see (sort of) trailing off to the left of the picture.

The LCD "zoom/review" focus method

2008-09-03T00:09:00.002-07:00

A simple way to focus your DSLR for astrophotography without a lot of other expense like a costly knife-edge device or laptop with cabling and focus control software, involves zooming in and reviewing diffraction lines from a bright star near the deep sky target. This method works best with a Newtonian telescope, where the secondary mirror is suspended by 3 or 4 straight flat bars 90 degrees apart within the optical tube assembly.

With diffraction lines, the zoom-review focus method can be accomplished very quickly. Three focus frames taken during the prior night's efforts are shown here.

The metal bars commonly referred to as "spider" vanes, cause the attractive (or distracting) star-like diffraction lines observed in my photos. I find it a pleasing photographic effect. For non-Newtonian scopes, one could fabricate some vanes to attach in front of a tube assembly to create diffraction lines just during focusing. I've seen some photos on other web sites where amateurs have used Photoshop to add the diffraction lines artificially (honestly, it looks as fake as it sounds).

You always want to try and focus on something nearby, as slewing the telescope clear across the sky can disrupt the mirror collimation on your touchy Newtonian.

NGC 869 and 884, the Double Cluster

2008-09-02T08:20:00.002-07:00

Another break in the storms, maybe this is the end of it. Under a beautifully clear and dark night, I was able to capture the Double Cluster below. Unguided, 257 x 15 second JPEG frames (roughly 64 minutes of exposure), 1600 ASA.

I attempted to get a parting shot of M6 too as it moves closer to the horizon, but the glow off my wall from my neighbors flood lights really ruined it. Even with 186 frames captured, it was like trying to take a picture with the moon out. Argh.

Messier 7, Ptolemy Cluster

2008-07-30T07:07:00.002-07:00

Unguided, 168 x 15 second JPEG frames, 1600 ASA

Messier 16, Eagle Nebula

2008-07-29T09:22:00.005-07:00

Alright, this is much better. Unguided, 201 x 15 second JPEG frames, 1600 ASA. I've also included a before and after comparison with previous take to illustrate the difference more "signal" can make!

Messier 31, Andromeda Galaxy

2008-07-29T08:12:00.002-07:00

Unguided, 201 x 15 second JPEG frames, 1600 ASA

A break in the weather?!

2008-07-13T20:11:00.003-07:00

Looks that way, possibly Tuesday or Wednesday night. Mark's weather station corroborates the reports, we've got rising temps and rising barometer. Window of opportunity may only be 3 hours at like 2 AM...at this point, I'm willing to do just about anything.

Misadventures in programmable calculating...

2008-07-13T19:47:00.002-07:00

Though my first attempt using the TI-83 was very successful, actually trying to program or debug what you've written is difficult. To be honest, you can only expect so much from a limited calculator interface. So those of you who wish to try, be forewarned its not as easy as it looks. You will undoubtably have to commit some time to learn and understand it.

Word of advice, if you make a mistake (any mistake) press CLEAR and ENTER to wipe out that line, and start over.

But hey, when it works, it works just great!

Another local weather link

2008-07-06T22:41:00.002-07:00

One of my wife's cycling buddies and his family has moved further east of here to St. David out near the Dragoon Mountains, and has set up his own observatory and weather station. The weather station is now online via the Weather Underground and I've linked his banner on the sidebar. Congratulations, Mark!

The Clear Sky Chart

2008-07-06T18:12:00.002-07:00

Stumbled across the Clear Sky Chart link. Provides some advanced notice on likely state of the skies, thanks to our Canadian neighbors! Lots of locations and observatories are currently supported. Searched on Vail and identified an observatory just 7 miles away from here belonging to none other than Dr. Levy, "The Comet Hunter." Heh. Just found out he and his wife live in Vail, too. I've inserted a link to their Jarnac Observatory sky chart in my page, we'll see how useful this is.

Where's the bubble?

2008-07-05T21:55:00.001-07:00

Tried my best to find some time between the storms at night, but the clouds keep rolling in. Below is my first attempt at the very bizarre Bubble Nebula, or NGC 7635. This night I threw out 45 frames due to clouds. Even with 125 x 15 second frames, there was still residual noise from some of the more sneaky clouds. As you can see in the picture, only the lower portion of the bubble is visible.

I'm just going to give up on deep sky objects until I can truly get a normal dark Arizona night sky. Sheesh.

Messier 17, Omega Nebula

2008-07-01T03:49:00.001-07:00

Intended to capture twice as many exposures as I did, but clouds rolled in quickly. This lovely object is also referred to as the Swan Nebula, not sure why. I don't see a swan. I see a lobster. In fact, in the southern hemisphere it is often called the Lobster Nebula.

Unguided, 94 x 15 second JPEG frames, 1600 ASA, dark frame subtraction, just stacked and stretched, no other processing.

Omega Centauri

2008-07-01T02:19:00.001-07:00

Wow.

This incredible globular cluster in the constellation Centaurus, known as Omega Centauri (NGC 5139), looked stunning in the telescope. Didn't get as many shots as I would have liked, it appears almost near the horizon. I quickly took as many as I could before it went down behind my brick wall.

Unguided, 23 x 15 second JPEG frames, 1600 ASA, automatic dark frame subtraction.

This globular cluster orbits our Milky Way galaxy. Only a few months ago, astronomers using the Hubble Space Telescope and the Gemini Observatory in Chile claim to have found evidence of a medium-size black hole at its core.

Using TI-83 as camera intervalometer

2008-06-30T23:19:00.001-07:00

Found a really cheap solution for hands-free operation. Introducing the handy TI-83 graphing and programmable calculator (emphasis on programmable). Told about this link regarding time lapse photography while surfing for a commercial solution. A good colleague turned me onto this; Geoff is a real jack-of-all-trades sort. Turns out the remote shutter jack on my Rebel XT camera is a 2.5mm audio jack. The data port on the TI-83 is also a 2.5mm audio jack. By programming a routine to time mirror lock up and shutter release, the TI-83 send() command is used to pulse the data line...the same way a remote shutter control pulses the camera. The only difficulty I encountered was locating a male-to-male 2.5mm cable. Only thing I could find was online at BoxWave.

This is so cool! As I type this, the camera is outside working on 200 exposures of M17 tonight. No need for a laptop and cabling, now I'm free to grab the binoculars, star map, a beer, or two. The picture below is a little fuzzy, but you can see my messages printing to the screen as it operates the shutter release.

I programmed the calculator with the following:

[7/13/2008] Thanks to Craig on Andy's Shot Glass site, I've corrected listing. You MUST use the programs menu to enter commands, and remember to use the STO key to assign values to variables (the -> notation):

300->T
Prompt I
Prompt E

T*5->M
T*I->S
S+(T*3)->R
T*5->P

For(N,E,0,-1)
Disp N
Disp “MIRROR”
Send(I)
For(D,M,0,-1)
End

Disp “SHUTTER”
Send(I)
For(D,S,0,-1)
End

Disp “BUSY”
For(D,R,0,-1)
End

Disp “PAUSING”
For(D,P,0,-1)
End

End

Disp "DONE"

Voila!

Monsoons

2008-06-26T07:58:00.001-07:00

Monsoon season is here. As spectacular as it is, puts a real damper on
my nighttime activity. Working around the phases of the moon is one
thing, but this just blows. All I can really do is wait, and enjoy the
light and water show.

Using a Barlow Lens

2008-06-17T08:24:00.001-07:00

The new T-ring adapter arrived, so once again I can trod out to the backyard and play around in the dark. I decided this night I would spend a little more time with that Barlow lens, maybe I was distracted last time I attempted this when the T-ring failed.

Increasing the magnification, compounds the effects of any errors you might have. I read that on a forum somewhere. It truly is the case. Focusing with a Barlow lens that effectively doubles the magnification, took 10 to 15 minutes! Really had to work to dial it in. This night was particularly challenging. A near full moon was out and monsoon season has officially started, so humidity was up. Any slight fluctuation in the upper atmosphere was readily apparent in the frames I collected.

The following picture of The Ring Nebula (Messier 57) was taken using a 2x Barlow at 1600 ASA, 175 x 15 second frames and automatic dark frame subtraction.

For the next several rounds of nightly shoots, I've decided to try working with JPEG format directly from the camera. I expected that it should dramatically reduce my processing time and have some impact on noise. The frames of this M57 photo were all captured in JPEG format. The optical effects of the Barlow don't help here in getting a fair comparison, but I found that capturing 150+ frames in JPEG format dramatically improved signal to noise ratio as compared to my other runs of 150+ frames in RAW format. It was really no comparison. I'm anxious to try this again in a normal prime focus configuration. For me, I'll use the Barlow approach sparingly where zooming in on a small object seems reasonable.

Rough night...

2008-06-09T08:31:00.000-07:00

Well, sometimes things just do not go well. Was late getting set up, didn't start taking pictures until after 11pm. Then about an hour in, I noticed the camera moved...by itself.

Apparently, the T-ring is broken. Camera spins wonderfully around on it, too. Not sure how this happened, I'm not that hard on it. Tried to complete, but I was worried about how much rotation I had to process out. Since the T-ring mount was no longer fixed, it was flexing in the wrong direction as well. Had to wait until all the photo processing was finished only to discover that with all the moving and shifting as the telescope slew, focus was not consistent through all the frames. A new $20 part is on order.

I also tried out a 2x Tele Vue BIG barlow, and through all the other frustration I found that even though the increased view is nice for smaller objects, the visual acuity seems to suffer. Stars are softer, not sharp, and though focused (I think) the digital image seems a little unnatural. It looks magnified. Seems a better approach would be to use a Newt with a longer focal length.

NGC 6960, Veil Nebula

2008-06-01T22:14:00.000-07:00

Unguided, 1600 ASA, 200 x 15 second frames, equivalent to 50 minutes of exposure. The Veil Nebula, also known as the Cygnus Loop, is a relatively faint remnant of a supernova in the constellation Cygnus. Interesting to note, the IR cutoff filter in my Canon 350D keeps most of the hydrogen emissions from being recorded, otherwise there would also be a significant red portion to the nebula.

Couldn't decide which portrait orientation I liked better, so I included both.

A Night at Kitt Peak

2008-06-01T17:39:00.000-07:00

Last night, my daughter and I drove 90 minutes to the outskirts of Tucson to the famous Kitt Peak National Observatory. From the base of the mountain upon which the observatory resides, we drove 12 miles and climbed to 6800 feet. When we moved to Vail, I was fairly impressed at living at 3300 ft. This was awesome. My daughter was very excited, she had been looking forward to this. She was not disappointed. I've captured a few of our photos below.

We made a reservation a few weeks back as part of their Nightly Observing Program (NOP). Last night they were completely full, at least 3 dozen in attendance. After a light meal, our host rushed us off to begin our nightly viewing. We broke up into groups. Twelve of us volunteered for the open-air roll-off building, and we had a chance to share viewing with a 16" Ritchey-Chretien scope. The Sky6 software was used to drive the system. The scope was hoisted on top of a Paramount robotic mount. Boy, if I had the bucks....

This next picture is of the McMath-Pierce solar facility, the largest solar telescope in the world. The above ground portion of the scope runs over 200 feet above the ground, where the rest runs another 300 feet under ground! The entire assembly (above and below) is refrigerated.

And here as you enter the visitor center, just two of the many domes across the mountain top.

This next photo was taken from our sunset viewing position.

Phone home anyone? Cell phones are not allowed, in addition to the glass and mirror telescopes the observatory maintains a few radio telescopes as well. They don't like cell phones there.

The obligatory big government commissioned observatory sign.

For academic and professional astronomers, this must be a great place to work. Around the site you can find dormitories attached or adjacent to each of the observatory domes. Apparently, to request a dome for research requires submitting a paper. If the paper is accepted, the wait can be 12 to 18 months. Each scope is booked for up to 3 astronomers every day of the year.

This last photo is of the 6-story tall Mayall 4-meter telescope. I'll let you figure out which one it is.

If you ever have the opportunity. Its a great visit. I would love to go back and try the Advanced Observing Programs, where you can spend a few nights using the observatories instruments yourself. You are treated as a visiting astronomer with complete access to their resources. It'll only run you $425/night per person, not including room and board which is an extra $80/night per person. Have to save my pennies...

Messier 13, Great Cluster

2008-05-29T02:37:00.000-07:00

OMG, I think I just advanced as a lifeform!

Unbelievable! I guess my premise was correct. Third time's the charm. This most excellent shot of the The Great Globular Cluster M13 in the constellation Hercules was taken on the night of May 26th 2008.

151 x 15 second frames at 1600 ASA, roughly 38 minutes of exposure time.

Look below, I included a before and after shot, just to pinch myself. Incredible. Guess I found the signal, Mr. Universe.

Messier 20, Trifid Nebula

2008-05-29T00:32:00.001-07:00

First result from my little experiment. How'd I do? Charles Messier discovered this heavenly object in 1764. The red emission nebula comprises a young star cluster near its center, and is surrounded by a blue reflection nebula. 99 x 15 second frames, or about 25 minutes of exposure. Only tossed out 6 frames from 105, and I was being picky. Thats roughly 5%, a sixfold decrease in defects!

Compare this to the earlier post of M8 and you can see here that the starfield of the Milky Way around M20 lacks the background noise and reddish glow. Stars are more pinpoint. I did pick up some coma in the far upper right; not sure if there was some tube flexure or impact from additional temperature drop.

A little experiment...

2008-05-28T22:19:00.000-07:00

I've decided to play with exposure settings. Over the last two months, I've extended unguided exposures from 15-30 seconds to 1 minute frames, and along the way observed how far the impact of tracking error goes. In any given run of 1 minute frames, I will throw out 30% due to noticeable tracking error occurring every 7-8 minutes. After spending 3 hours to take the photos, that seems like a waste of good photons.

"Well, duh!", is probably what some of the hardcore computerized brethren would say. Yes, I could get an autoguider cam, get out laptop, install software, add more cables, adjust guide scope to reasonably bright star, and consume more time in setup and prep.

Or...I could simply take shorter exposures and significantly increase the quantity. Its all about the signal. As Mr. Universe would say, "You can't stop the signal, Mal."

I believe taking a very large quantity of short, high-gain exposures will produce a more desirable signal to noise ratio in the end, reducing much of the 'blowout' in some of the brighter nebula and globular cluster shots, thereby producing richer results, without turning my scope into something from The Matrix. -- So Say I

The emphasis here is on digital astrophotography with the minimum amount of gadgets and expense. Once confidence and happiness is achieved at this level, you certainly can go up ($$$) from here as far as your wallet will take you! IMOP, the most expensive piece should be a quality, motorized German equatorial mount with computerized GoTo handheld. The GoTo saves a significant amount of time and is self-contained. A simple OTA for light gathering should not cost more than $500, and at that cost, driven by your desired aperture. A high-gain DSLR camera body can be found online or at your local fence for $400 or less, providing mirror lockup and automatic noise reduction (dark frame subtraction) built in.

* leveled mount and polar alignment via polar scope (a few minutes)
* 3-star GoTo system alignment (5 minutes)
* laser collimation (less than 30 seconds)
* DSLR focus with LCD review/zoom method (1 minute or less)
* unguided photography using shutter remote for as long as your camera has power and your CF has memory left (3.5 hours)
* beer, coffee, or both (your choice, no time limit)

Folly? I'll let the pictures stand on their own merit. You can all laugh at me later. The next round of astrophotography will be captured this way, without making any changes to post-processing method.

Skol and Compai!