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.
Saturday, July 25, 2009
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.