Here are two articles by Roger N. Clark, an astronomer, about low light performance. He compares the Canon 5D Mark III (Full Frame) to the 7D Mark II (APS-C) in low-light situations. It is quite technical, but the conclusions are understandable. He says the low-light performance of the 7D Mark II (the APS_C) camera is as good or better than the 5D Mark III (Full-Frame) camera. I had found the same thing with testing of my own, but was encouraged when I ran across Roger Clarks web site. He points out that the lens is more important than the size of these modern targets. I do not believe this information is widely known. Here are the web-sites: http://www.clarkvision.com/articles/does.pixel.size.matter/#Conclusions AND http://www.clarkvision.com/reviews/evaluation-canon-7dii/index.html Hope this helps. Ken

While I understand the importance of a fast lens, the use of a tripod, and that we've discussed many times the advantages of a "Full Frame" sensor when it comes to overall low light performance, I am pretty much stuck in a crop sensor world for my photography hobby. This is primarily because of the price differences, but it is also due to the overall, physical size of the FF, DSLR's that I have had the pleasure to handle personally, with say the Canon 6D being about as big as I would ever care to go. While neither of my DLSR's are noted for their low light performance, I do okay with my Pentax K3 and/or my backup Canon T1i. However, low light performance has always been a big disappointment for me with either camera. While the K3 has a much higher ISO range than the T1i, it also appears to bring in more noise at comparable ISO settings and frankly, neither is really acceptable to me above say ISO 1600. I guess going higher with the ISO is better than not getting a shot, but even after extensive efforts in post processing, the noise levels are bothersome to me and I have to wonder if there isn't a crop sensor DLSR or Mirrorless body out there that could be a real improvement in overall low light performance without having to move up to a FF sensor.

Therefore, I am interested in discussion on which crop sensor body might have the best overall low light performance (not just how high I can set the ISO, but more about the results when I do use a high setting). I'd also be interested in what I should be looking for as I research this area of performance in today's offerings, as well as any other less equipment related tips you might be willing to share. Before you ask, I am on a fixed income and my photography budget is a lot lower than I like it to be. Therefore my personal, yet optomistic, budget would have to be under $1000.00 and I would prefer to find something used and save every dollar I possibly can. I'd be very willing to do without things like GPS and WiFi as long as there is real improvement in the low light performance. Thanks and good shooting to all.

How about a Nikon d7100 and a forty year old plus, Nikon Nikkor 50mm, F1.8 AI lens? Shoot in Aperture priority mode, since the camera recognizes the lens. Lens can be bought from Japanese camera stores on eBay from $50 on up depending upon the condition but most are pristine. A new d7100 can be bought from B&H Photo $796.95 and used ones any price under. If you decide to move up to a full frame camera, your lens will work. Don't forget that you can buy a new d750 on B&H, with a multi power battery pack, batteries, and 64gb card for $1396.95. Hope some of this helps.

As you've already indicated, Chris ... just opinions ... never thought of the D810 as being BETTER in low-light performance than the newer D850!

As to the D500 being lighter than the D810 / D850 / D5 (especially that one) ... it's STILL a heavy camera!!!!!

I suspect you gave the edge to the D5 - because of the higher investment ... certainly it's quicker, but surely the D850 has the edge in LLP.

Anyway ... just my reflections ... haven't had any hands-on with any of them ... the D7100's more my speed ... lighter, by far, than the D7000.

I suspect - when all elements are factored in ... the D7500 has the best compromise of LLP and lightness ... but, that's just my take ...

Happy Shooting, Chris ....

The size of the sensor does not determine the amount of light a camera takes in. Its the shutter speed and the aperture that determain. Now the quality of the sensor does determine how light sensitive you ISO can go up to. But, ISO is only electronic gain and that is what causes noise. So the same lens on a full frame and on a crop sensor let in the same amount of light. So when buying a new camera look for better ISO clarity and low light sensitivity to get better exposure in low light situations. Image stabilization can help you get one or two extra stops in low light situations too. I have a Nikon D500 and love it. I can shoot in virtually no light and get an image. On a D850 full frame can beat it. Just barely.

The size of the sensor does not determine the amount of light a camera takes in. Its the shutter speed and the aperture that determain. Now the quality of the sensor does determine how light sensitive you ISO can go up to. But, ISO is only electronic gain and that is what causes noise. So the same lens on a full frame and on a crop sensor let in the same amount of light. So when buying a new camera look for better ISO clarity and low light sensitivity to get better exposure in low light situations. Image stabilization can help you get one or two extra stops in low light situations too. I have a Nikon D500 and love it. I can shoot in virtually no light and get an image. On a D850 full frame can beat it. Just barely.

Here is my summary of cameras sorted by low light performance.

As I mentioned in my previous post, the APS-C to APS-C comparison is fairly accurate; however, comparing full frame, 1" and APS-C sensor performance has to take into account crop factor (and probably a few other factors, not the least of which is the sensor design/technological age).

I've owned and/or used a fair number of the cameras on the list. The summary is fairly close to actual performance, except for probably the 1" sensor cameras.

bwa