Quote Originally Posted by Bill_in_WA View Post
Like you the 70/200 is about the longest reach I can go to indoors... The 100/400 will have to wait unless I can convince the art store in town to let me use some floor space after hours (The lighting would also be good).
Ever been to an eye exam where the chart is projected off a couple of mirrors in a Z configuration before you see it? There's absolutely nothing that says you can't do the same thing. If you have access to optical-grade front surface mirrors obviously use them. However, any mirror that you can look into and see a 'normal image' as opposed to a warped, 'fun house' image will work just fine. Be sure the mirrors cover the maximal rays that will enter the pupil of your lens (lines from the edges of the target to the outside edge of the front glass). The partial reflections you'll get off the glass should have nearly no effect at the working distances you're discussing.