My Sigma 600mm f/8 mirror lens arrived today, and after futzing about with it, I noticed it was a clear night outside. Even better, the moon hadn’t quite set yet. I got off a few pictures before it was lost to the trees. This is the best one:

I do have a couple of notes for people looking at mirror lenses:

First off, they aren’t nearly as sharp as the auto-focusing magic zoom lenses you have in your bag. Mostly because you don’t have auto-focus, and manipulating the focus ring at 600mm is an act of incredible patience. Even worse, tripod shake is always an issue for night work at 600mm, so you have to set the shutter delay or use a remote. Live view is a miracle at 600mm.

Second, it takes some work getting the exposures figured out. The lenses don’t have any electronics in them, as best I can tell, so all metering and focus information is manual. You’ve got to figure out what you’re looking at, how bright it is, and work it all out yourself. Sadly, for metering, live view is useless, at best. (It also ruins your night vision and drains your battery. Fun!)

Third, if you’re an idiot like me, you won’t realize at first that there’s a 4X Neutral Density filter in the filter holder. It makes it nearly impossible to take pictures handheld, even in daylight at ISO 6400. When you get the lens, check the filter holder, which usually slots into the back of the lens.