Traingineer: I have no plans to mess with the 5D III. I use it for my bird, wildlife, and landscape photography, so I don't want to mess with it's ability to produce high quality, accurate color. I plan to buy a cooled mono Astro CCD soon enough, with a full set of LRGB and narrow band filters, which will trounce anything a modified 5D III, 6D, or any other modded DSLR could do. I expect, in the long run, to have a few cooled astro CCD cams. Different sensor sizes and types are useful for different things, some have huge sensors with lower sensitivity great for ultra wide field stuff, others have small sensors with insanely high sensitivity (77-90% Q.E.), great for deep narrow band imaging.
Bean: I use my Canon EF 600mm f/4 L II lens as a telescope right now.
Here is another image from Cygnus. Just took the subs for this last night, and just finished nearly six hours worth of integration/stacking and processing. This is the Sadr region of Cygnus, the close neighboring region to the North America/Pelican nebulas I shared before.
There are multiple objects in this region. The Gamma Cygni region, comprised of IC1318 A, B, and C, also called the Butterfly Nebula by some, is in the lower middle. This one field also contains two open clusters, M29 and NGC6910. The bright star is Sadr, one of the primary stars that make up the constellation Cygnus itself. A big dust lane (unnamed, as far as I can tell) stretches through the center. A small double star near the lower right of that dust lane is also a reflection nebula...light from the blue star of the pair (barely discernible here) reflects off the dark dust. Another reflection nebula can be found in the upper left region just on the border of one of the darker areas (again too small to really be seen here).
As with most of my images, I was only able to gather about 1/3rd of the total subs I needed to get the best quality. All of my images have around 35-50 individual frames (subs) integrated. I need at least 100 subs to reduce noise to an acceptable level (100 subs averaged together reduces noise by SQRT(100), or 10x), and these days, with summer nighttime temps in the 70s, I probably need to reduce my noise levels by twice that. Problem is, to reduce noise by 20x, I would need 400 subs!!
Hope to get some time this weekend to start building my cold box. I received my copper plate a couple days ago...so I can solder it together and put some insulation around it. Peltiers and voltage regulator are still on the way, and I need see if I can pull apart this indoor/outdoor thermometer to get myself a temperature sensor and readout screen that I can embed into the box. I'm hoping to be able to cool my camera to around -10°C. Compared to the 30-35°C it runs at right now, I should be able to reduce dark current noise by 6-7x.