Hector1970 said:
I'd find the 5DIII much better than than the 5DSR (which I assume is like a 5DS) in low light.
The 5DSR may recover shadows better but the overall quality of the image degrades faster than a 5DIII as the ISO goes up.
I've done alot of side by side shooting with both indoor and the 5DIII produces far more usuable images.
I have the 7D II as well and its perfomance is similar to the 5DSR. It's also poor in low light / high ISO. They have a similar/same? sensor.
I really only use the 5DSR now outdoor on a tripod at ISO 100. This is it's strength but I find it limited otherwise.
I'd use the 5DIII anytime any place.
If it gets cheap on the arrival of the 5DIV / 5DX I'd highly recommend buying the 5DIII.
It's a great camera that would serve you really well for years.
I don't think you'd be compromising anything. The focusing system is very good. FPS might be slightly limited but its not bad at all. A super all round camera.
This begs one question: when you are comparing the 5DS to the 5D3 in low light, are you downsampling the shots to 22 MP? That reins in the noise considerably.
So if you are not downsampling, the 5D3 should beat the 5DS for low light performance.
If you
are downsampling, I've heard everything from 'it's a dead heat' to 'the 5DS is slightly better'.
Or, from
Bryan Carnathan at TDP (this passage below is about 1/4 of the way into the review):
"When compared at native resolutions, 5Ds images are noisier than 5D III images. The differences, especially at higher ISO settings, are less than 1 stop. Down-sized to 5D III pixel dimension (using DPP, see "Standard Down-Sized to 5D III" in noise tool), 5Ds noise levels are essentially equal to full frame 5D III noise levels and even slightly better at the highest ISO settings. So, while Canon is not promoting this camera for its low light capabilities, I see it as one of the best options available with output size being comparable. "
Parsing his thoughts another way, a 5DS is a high detail monster in good light / tripod / studio conditions where you can keep the ISO low, but when ISO climbs, it's like you switch to "5D3 mode" by downsampling the 50 MP down to 22 and the shots look fine. So, crudely: a 5DS is a high res rig in good conditions and it 'becomes' a 5D3 in poor conditions. That's not a bad thing.
- A