What's' a good used budget full frame camera 2018 ?
I always been crop sensor guy and now the older full frame camera are cheaper.
wondering if its worth picking up.
The camera I'm thinking about
Nikon D700, Canon 1ds Mark ii, Sony A7.
Budget and Full Frame rarely go hand in hand. Not only are the lenses more expensive, the cameras are much more expensive as well. If you like the quality of your photo's keep your crop sensor. You can't use crop sensor lenses on a full frame camera.
When you shop for used, you no longer can judge by brand and model alone. What matters most is camera condition so that means check the camera first personally before paying for it.
Don't forget to consider Pentax, one of the best brands there's.
Lack of advertising is no indication of lack of quality!
Nikon D700 - A 12MP DSLR from about 2008. At the time, it was a great DSLR if you didn't need a camera with more resolution so that you could make larger prints. With just 12MP, the sensor has very large pixels which make it great for low light work.
You can see sample images here, but keep in mind that unless you use the same quality lens, you won't get the same results since the lens is what determines sharpness, color, and contrast (yes the sensor has some influence, too) among other things:
This link to dpreveiw.com will show you the ISO performance at all settings:
While the link above is for older cameras, dpreview has another web-app that shows the ISO performance of the Canon 1Dx Mark II, and the original Sony A7:
As you can see with this 2nd link, the Canon 1Dx Mark ii does a significant better job at high ISO settings than the Sony A7. However, as expected, the D700 just kills the 1Dx Mark ii at high ISO settings.
So if high-ISO performance is a major consideration, and you don't print larger than about 11"x14", then go with the D700.
The 1Dx Mark ii was designed more the for the sports photographer and photojournalists. You see this in it's ability to shoot at 16 fps, vs the D700's 8 fps, and the Sony's 5 fps. Because of its rugged design against shock, moisture and dust, it's a great workhorse of a camera.
The Canon utilized an USB 3.0 interface which downloads data 10x faster than USB 2.0 which is used by both the D700 and A7.
The Sony A7 has an advantage over the 1Dx Mark ii and the D700 in that it can use any lens by any brand via lens adapters. Down side to this is that the AF performance suffers. It's been shown that the earlier A7 models work better with Canon brand lenses vs Nikon brand lenses. I say "brand" because the AF performance drops when used with 3rd-party lenses with the Canon EF mount.
At 24MP, the Sony A7 has the highest resolution of the three cameras. This enables you to print larger while maintaining photo quality prints. However, as the ISO comparison shows, you give up high-ISO performance in order to make larger prints.
A problem that you will have with the A7 is its focusing speed, or the lack thereof. It uses contrast focusing so it can't keep up with moving subjects like the 1Dx ii or the D700 can. So if you do sports, wildlife or fast moving subjects a lot, then definitely skip the A7 and go with the 1Dx Mark II.
Here's a side-by-side comparison of major features: https://www.dpreview.com/...ts=sony_a7
Here's an in-depth review of the actual performance of the A7: https://www.imaging-resource.com/PRODS/sony-a7/sony-a7A.HTM Most reviews just talk about the same general specifications. Imaging Resource tests these cameras for things like buffer size which is huge if you're constantly shooting at 16fps. A lot of cameras show that they shoot at, say, 10 fps. But they fail to mention that their internal buffer can only hold 5-10 images before the buffer is full and the cameras goes into limp mode where the fps drops to just 1 fps.
As you can see, these cameras all have weakness and strengths. Depending upon what types of photography you do, and even which lenses you want to use, one will be better than other.
Don't purchase any older full frame camera… Sensor of today's camera has much low light or ISO capability than previous generation camera…