Okay, I contacted my hosting service (GoDaddy), and got things straightened out. Here are a couple of examples of crops using a mirror lens. The lens was a Sigma 600mm mirror I bought new back in about 1984. These are film images. The first one is Fujichrome 100 and the second one is Kodachrome 64. There will be grain.
The first full image, resized for display here, an SCCA Sports 2000 class sport racer:
And a 100% crop of the above image:
This second image is actually a color Kodachrome slide, but the reflections off the water were so intense, they washed out all color:
And a 100% crop of the above image:
I was using a monopod with my Sigma 600 in the first shot and a stout tripod with the Sigma for the second shot. As you can see, even though I was shooting with film, detail is very good. I can only imagine what it would have looked like if I shot these images using my current 24.3mp digital.
So anyway, all I'm getting at is it is indeed possible to get good, usable crops from a quality mirror, such as that above Tamron, providing that proper technique is being followed. In fact, really, I'm restating the obvious, since there are several excellent images on the preceding page that have rendered outstanding crops.
Last edited by cooltouch; 05-23-2019 at 08:09 AM.