therwol wrote:
Another way to look at it is this. I paid 3 grand for a D810 with 36 megapixels. If I felt I needed only 15, I would have bought a different, cheaper camera. I've argued in this forum that the ability to crop with the D810 is a distinct advantage, but it shouldn't be the goal of using the camera. The OP should buy a longer lens, and there are good recommendations in this thread. The recommendation of using his current lens on a DX camera is also valid.
I have 3 cameras. One is an older D70s (DX) one is a 4 year old D7100 (also DX) and the third is a D610 (FX). I use the two DX cameras for anything requiring "long" shots. I get the (roughly) 1.5 multiplication factor on my long lenses. On the other hand, I use the FX for anything requiring wide to short telephoto. Both the D7100 and the D610 compliment each other in terms of coverage. I can always put the D610 into "DX or crop mode" with the loss of pixels you commented on (the D610 is a 24mp fx so in DX it would be roughly 17 or 18mp. Or I can use my 24mp D7100. For me each has its best uses. And I am rapidly converting my lens inventory to FX lenses as both work well on both cameras with no loss of compatibility. I also use all on my D70s (the wife's camera).