As much as I love MFD, it really is not that well suited for astrophotography...I discovered that too late! But now I also use my Mamiya lenses on a 5DII as well .
Ray
Perhaps not!
Hi,
I am not an expert, but over the last few years I have learned some very interesting things about digital astrophotography. There are some wonderful techniques that can be used to tame the noise generated in sensors during longer exposures. Much astrophotography is done with CCDs that can be pretty noisy. With the right techniques, you can get rid of the noise!
If you have not looked into this topic I can recommend the book:
The New CCD Astronomy by Ron Wodaski.
It is amazing what stacking a few image frames can do to reduce noise. Four stacked will make a significant difference in reducing noise. After 16 frames, the gains diminish quickly. Also, if you take the time and create a series of calibration frames (dark, bias, and flats) and apply them your image, quality will improve even more.
There are some fantastic software tools for both Mac and PC users that are free, or very inexpensive, that make processing digital images easy. One favorite is Nebulosity by Craig Stark of Stark Labs.
As an overview: you shoot your image files and put them in a folder. Shoot your dark frames, put them in a folder. And so on with your flat and bias frames (if you elect to use them). Then fire up a program like Nebulosity. The software will ask you to point to your dark frames. It will then stack them into a master dark frame (with low noise) and save it. You do the same thing with your flat frames and your bias frames. You end up with a master frame for dark, flat field, and bias.
Next, you tell the program the folder for your image files. Typically you will shoot 4 or more frames of a single subject on rig tracking the sky accurately like the AstoTrack mentioned in the original post. The program will work with you to align and stack the image frames. At this point the stacked photos will be nice. But then you tell the software to apply the master calibration frames for dark, flat, and bias, and everything gets even better. Noise should be all gone. Your image should be free of any natural vignetting. You will still have work to in order to stretch the image, correct color, sharpen, and so on, but your starting point should be massively better than if you had made single frame of the night sky.
One final point. It is important to keep the sensor as cool / cold as possible. Heat equals more noise recorded. Dedicated astro imaging cameras use active cooling systems to manage the heat. Big observatories will use liquid Nitrogen cooling. I have found shooting on cooler / colder nights vs on a warm summer night makes a difference in image noise.
Ray, I bet you can do some terrific asto work with your MFDB. With accurate tracking, good focus, and some free / inexpensive software I think you will be as surprised.
Cheers,
Paul