Always make sure the batteries are charged

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...

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

Second night out

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...

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...

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!!

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

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...

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

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

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

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

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

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

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

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

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...

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

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

Messier 52

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

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.