The impact of heat on noise is very interesting. Thanks.

Many thanks for confirming that these cameras work in extreme temperatures! Something else may well be going on, and already I'm checking to make sure the shot registers on the LCD immediately after taking it. I notice sometimes that 15 or more seconds can pass before a shot goes into the card (and I've tried different cards), and that sometimes the playback just goes dead. Electrics! But I'll keep at it! Bill

After a long walk in the woods, deep snow, and 10 degree temperatures, I came back to find that a dozen and more shots I'd taken (D800) hadn't registered at all -- blanks. User's manual says that operating range is 32 to 104. Neighbors have suggested issues with digital cameras in the cold. Is it really the case that they can't operate in Arctic and Saharan temperatures?

Thanks, Scott. Good to know. Bill

With the AIS lenses and my D800, I can use aperture priority mode as well as manual: I set aperture on the barrel and the camera handles shutter speed. And I get spot metering. If ISO is set on automatic and you're in manual mode, you don't even really need to make adjustments, since the camera compensates automatically. Somewhere I read that AI lenses do not provide the option of aperture priority or spot metering -- but I'm not sure.

All very useful comments and much appreciated. Thank you! I myself have had no difficulty getting the focus right with that admittedly shorter "throw" of the focus ring, but that is a point. But still, what did happen to those split images and microprisms? Or the little needles on my old Canon F1 that allowed me to alter aperture and shutter and keep the exposure correct as long as the needles were aligned? With the D800 I finally feel myself getting back to the level of control I had with that F1!

Many thanks! I look forward to checking out these sites and learning more. I should say that some of my favorite lenses are Leica screwmounts that go back into the 1930s, so I'm not overly worried about missing out on the latest technology! I also should say that my 50 mm is an AF, the f/1.8 D, inexpensive, and excellent. Thanks again!

After reading Ken Rockwell's article on Nikon lenses for cheapskates I bought a 28mm f/2.8 AIS and a 135mm f/3.5 AIS for my D800. I've found autofocus so chancy in the photography I do that using manual is quicker, easier (no backbutton focusing or quitting on the autofocus attempt), and reliable. These two AIS lenses allow aperture priority, so you set that on the lens barrel and the camera handles the shutter speed. Entering the Non CPU data in the Steup Menu gives you the apertures in the viewfinder. And I get spot metering. Razor sharp, excellent lenses, at incredibly reasonable prices. And none of the distortion inherent in the zooms.

Just in case someone thinks I'm one of the "clowns" for preferring the D800 to the D7100 (which is an excellent camera), let me say again that the issue, for me, wasn't so much full vs. cropped frame (and, for me, that was important, and I can tell the difference), but the usability of the viewfinder and the cramped, hard-to-use controls on the D7100! The arguments I'm reading here all focus on full-frame vs. cropped and overlook the other considerations! A camera that falls to the hand of the photographer produces better results -- and greater pleasure!

I bought a D7100 a year ago and traded it for a D800 this summer. The D7100 functioned beautifully, the 18-140 lens was excellent (though distortion high). Several features of it escape mention in all the comparisons with the D800 series I've read, and for me proved critical. 1) The viewfinder -- a major reason for me to move beyond a high-quality point and shoot -- is tiny and dark and prevented me from composing my shots. I oftne had to take picture after picture to get it right, and sometimes couldn't. Since auto focus doesn't always work, the only alternative is manual, which works poorly because of the dark viewfinder -- I couldn't tell whether the image was sharp. Moreover, there is no distance scale on the lens barrel, so you can't even set it on an approximation of distance. 2) The smaller size and lighter weight -- compared to the D800 -- meant, for me at least, contorting hands and their muscles into unusual and difficult shapes. Nothing fell easily to hand, and I even had to check, visually, to make sure my index finger was on the shutter release. Single buttons serve multiple functions, and just trying to remember them all, in the field, often proved impossible -- and no, I didn't carry the manual around with me. 3) Photos, sharp as they were, came across as two-dimensional. In short, I found the D7100 substandard in comparison to normal film-SLRs of the 1970s. What's important here is the comparison with the D800. Yes, full-frame often is somewhat sharper, but the real difference there is the three-dimensional quality of the photos. As important, the big, bright viewfinder finally has allowed me to take pictures as I did many decades back. And the larger size fits the hand and accommodates the necessary buttons and functions easily and intuitively. In short, the D800 allows me fully to function as a photographer once again. I'm not sure why the differences noted here don't figure in the comparisons I've read.

Many thanks for your counsel! Most helpful!

I'm interested in trading up to full-frame and note a $300 or so difference in used D800 and D800e prices. Thoughts?

Back in the good old days of film SLRs, you could focus on that point which you wanted in focus, then set the exposure for the spot that needed correct exposure, and press the shutter. The only way, cumbersome as it is, to achieve the same results in a D7100 is to use exposure lock (half-way pressing of shutter, after setting exposure lock) and back button focusing, that is, the separate out the focusing and the exposing. Spot focusing and spot exposure don't always go together!

How about Leica V-Lux 6 vs. Panasonic?

How about Leica V-Lux 6 vs. Panasonic?