This little mirror lens is really freakin' cool!!
Overcoming camera-shake blur is a challenge, primarily because of the single stop (f/8). On the D3, it isn't a big deal, but to get a decent shutter speed when properly exposed, I found I was having to shoot at least ISO 500 in bright daylight. ISO 1000 gave me the sharpest images with it, since the shutter speeds were in the 1/2000th range with that setting.
Lots of people bitch about this lens's lack of contrast and soft-focus. I say that's crap (click
here if you want to look at full-sized images to get an idea of how sharp it can be). It's a non CPU lens, so you have to simply be careful about the exposures you use in Manual mode. It's definitely a bright daylight lens or high ISO lens, though...especially when hand-held. Put it on a tripod, and it still suffers from a bit of camera-shake blur because it's just flat-out too light. I found that adding a little weight to the tripod helped a lot.
The ring-shaped bokeh is either a bonus or a problem, depending upon who you are and what you're shooting. Personally, I think it adds an interesting feel to the backgrounds of these images.
All in all, though, I think this will be a nice little addition to my bag of tricks. It's very light and very small compared to even my 70-200mm f/2.8 (it's about the same size as my 24-70 and about half its weight).
Fun stuff.