Stan hit most of the highlights. I will just chime in with a couple of points...
>Shooting RAW, shutter priority at 1/200, manual focus (to >avoid hunting in low light), ADR off, high ISO noise control >off, auto WB, manually set ISO just above the LO warning. I >check the histogram after each shot.
I pay little attention to "lo" warnings. In fact, I pay little attention to nearly anything my camera tells me unless it is something unanticipated.
>When shooting from the first row, there is a lot of black on >the lower 1/4 - 1/3 of the frame: big waste; this is the >front wall of the stage. I avoid letting this factor into the >ISO setting, but obviously it needs to get cropped out, so it >is part of the reach issue.
Yep, you need more focal length.
>The light is all overhead stage lighting, so I use a lens >hood. The director seems not to like using spots. The >lighting director argues with the artistic director that the >light is insufficient. The lighting director is correct, but >loses the argument.
And here is the crux of the matter. I'll come back to it.
>I had >guessed (apparently wrong) that f/1.8 and a 50% crop was >better (from a noise aspect) than f/2.8 and no crop.
A 50% crop is a LOT. I'd certainly take the 2.8 and no crop.
>... Meanwhile, I have been looking to capture grands >jetees, etc. (Mostly, I shoot sports.) The director is >looking for those shots from me.
Wonderful. Alert the director that your hands are tied because the light levels are barely sufficient for audience viewing, much less photography. And if he (or she) is looking for action photos, then the light level will need to be increased, or strobes will have to be brought in.
>To summarize: solve the reach problem first to avoid cropping >(but the 70-200 f/2/8 is about $2400, the new f/4 is $1400).
The Nikon 80-200/2.8 is around $1100 new and around $500 used (older model).
>Then, avoid high shutter speed if the lighting won't support >it (up to ISO 3200). This appears to come before the issue of >moving to a used D3s. Unclear, though, is where in this plot >moving to a D600 fits.
I want you to pay VERY close attention to the following image that was shot on a D600:
This image was shot at ISO 100. That was a mistake. I was shooting some statics, then changed to my other camera. When the action started I picked this camera back up and started to shoot. I did a few frames before I realized I had not changed my settings from ISO 100 to the correct ISO 3200. So... this image was exposed FIVE stops under. I corrected the exposure in Lightroom, cleaned up some noise, and did a fairly significant crop. Then published it. You can see the result. Had I not needed to crop this image, it would have shown much better.
The D600 captures an AMAZING amount of detail and has incredibly latitude. The D700 is also very good in this regard though not quite as good as the D600. Should you choose to move from the D7000 to the D600, you may find you need to change lenses depending on what you've got.
>Your explanation about the Canon vs Nikon sharpness comparison >is very enlightening. The other thing I noticed (on DPR) is >that with NR OFF, comparing the noise levels among the MKIII, >the D7000, and the D600: at 6400, with NR off, the D600 and >the MKIII are quite close, and the D7000 is a little (a vague >term) noisier. Or is the comparison meaningless?
I shoot both Canon and Nikon. I have many friends who shoot Canon. We often shoot side by side at the same events. I gentleman shoots a Canon 1DMk4. I can say with complete confidence his camera is no more clean than my D7000. I have RAW images from him. If we take the 1Dx off the table, the D3s and D600 are cleaner than anything Canon makes. The dynamic range is superior too. I dare you to shoot a 5Dmk3 at 5 stops under and give me a file that looks like my photo.
There are several solutions to your problem. The best is to simply get more light on the situation. The next best is to eliminate the need to crop images by getting focal lengths that will work for you. And finally, you can look at changing cameras.