Yeah, Dave, I see your point vis-a-vis a newbie with a mirror. However, one must learn sometime and somehow and a mirror lens *can* be easier for a newbie if only because it doesn't require much thought beyond focussing. A pre-set presents different operating problems and can be distracting, especially to folks who are generally used to auto-aperture lenses. As well, compact size and light weight are conducive to actually *using* a long lens. A lot of people give up on long tele-photography simply because the long-focus and true tele lenses are a PITA and bulky. One other, less considered, point is the mirror's close-focus ability compared to comparable refractors. I consider the 10 to 30 ft. range rather critical, particularly in bird photography and a mirror allows the use of a relatively powerful tele in such close quarters. The contrast problem is alleviated considerably at such close range if only because there is less atmosphere to get in the way. All that said, I personally prefer a long-focus lens for the majority of my wildlife stuff. I don't consider using extension tubes on a true long lens a viable alternative to closer focussing except in instances where I know I won't need the longer reach for subjects farther away, which is almost never. That's the job for the zooms.
Originally Posted by Satinsnow
As to stop-down metering, it is often far more accurate, in my opinion. And don't get me started on tripods, please! If I had a nickel for every time I stressed the use of a decent tripod to someone, I'd have Bill Gates for lunch. And, yes, you can pretty much forget about getting anything worthwhile without one when shooting with long lenses, that's for sure.
from Deepinaharta, Georgia