In hand is a Canon 200mm f/2.8 prime focus lens that I have loved for daytime use and have used at night with a 40D camera.
Have recently bought a QSI583 for use with an imaging refractor but then picked up the proper adapters to use Canon EOS lenses as well. You maybe see where I am headed here and that is my starting to wonder if there was some way to fool a Canon EOS lens into keeping it's aperture around f/3.5 even after it is removed not only to obtain sharper stars in the corners but also to minimize vignetting through the QSI583 1.25" filter wheel small area.
Feel free to laugh and tell me it is impossible but feel even MORE free to tell of a way that this can actually be done.
Again the idea is have a stopped down Canon EOS lens mounted on the front of a CCD camera where there is no control for aperture electronic signals.
Thanks for any thoughts.
