I'm thinking of getting an old full frame DSLR.

[tecboy]

I volunteer a little school to photograph preschool kids, and they don't let me use flash. Do you think this one can handles low light. I'm not too crazy about the resolution. I submit the photos to them in 2mp resolution.
CANON 5D DIGITAL CAMERA BODY 12.8 M P - KEH Camera

 

[sashbar]

I have never had one, but from what I know it is a great portrait camera with good skin tones, but anything above ISO 1600 is not up to scratch by today standards. It has no advantages in low light over modern APS-C sensors. Otherwise it would not be so cheap. Just my 2 p. Lets hope some owners will give their verdict.

 

[bratkinson]

As noted by sashbar, ISO speed may be your limiting issue with the camera. Also, as a full frame Canon, your EF-S lenses, if any, won't mount to the camera.

Low light shooting of moving subjects (even posed!) requires high ISO speeds, fast glass, and shutter speeds generally 1/125 and faster. The exposure triangle tradeoffs can sometimes be brutal. When I had my 60D, I could sometimes 'push it' to ISO 3200 and get acceptable results, but most of the time, I preferred 1600 or 2400 for low light work. That sometimes resulted in a bit too-slow shutter speeds to freeze motion. 1/20th, 1/40th, etc, you'll get subject motion blur in 4 out of 5 shots...or worse. And as preschool kids aren't known for sitting still longer than 1/125th of a second, you'll likely need fast glass and be forced to deal with DOF too narrow for group shots larger than perhaps 6 kids.

In short, if you're looking to buy used, I think I'd go with a used 60D, 70D, or even a 7D. That way, you get a camera with decent ISO capabilities, perhaps better auto-focus abilities (I never used a 5D or 5Dii), and if you have EF-S lenses, you won't be forced to upgrade unless you need something in the f2.0-2.8 range. Also, in smaller spaces with a crop sensor, a group of 5-6 kids 10 feet away will require a focal length of 16mm, give or take. The good news about 16-30mm or so on a crop body, is there's very little keystoning (converging/diverging vertical lines) as the distortion is more apparent closer to the outer areas of the image, which is cropped away by the camera.

 

[tecboy]

My 70D looks okay with very high iso around 4000. The flash makes the images look much better. If I sell my 70D and get a 6D, I don't think I will get good pictures quality without using a flash.

 

[bigal1000]

It's a great camera as far as I'm concerned, I have a 24-105L on it and it does everything I need it to do. I'll probably upgrade to a 5DIII in a couple of years.

 

[bigal1000]

My 70D looks okay with very high iso around 4000. The flash makes the images look much better. If I sell my 70D and get a 6D, I don't think I will get good pictures quality without using a flash.

How come ?

 

[astroNikon]

In the Low Light ISO numbers from DXOMark
the 5D though a FF, is above all crop cameras @ 1368 except the Nikon d3300 which is @ 1385
The 6D is @ 2340
==> dxoMark Nikon ISO numbers Photography Forum

So the newer Crops are catching and surpassing it now.

 

[tecboy]

My 70D looks okay with very high iso around 4000. The flash makes the images look much better. If I sell my 70D and get a 6D, I don't think I will get good pictures quality without using a flash.

How come ?

I dunno. I never had a ff before. I have met few photographers with 5markIII, and their photographs don't look very good even thought they don't use flash at all. With flash on my 70D, the subjects pop and the colors are more saturated.