I currently own a 5D3 and a 7D. I still have the 5D2 my 5D3 is meant to replace and am waiting for the market to clear a bit before selling it.
Yesterday I photographed a pair of hooded mergansers that I had earlier photographed with my 7D. The lens was the same - 70-200/2.8 II + 2x III, and the location was exactly the same. I also photographed the birds at the same exact location in the pond with both cameras. The only difference was the shots were taken several weeks apart.
I was curious to compare them, so I took two photos of the same merganser at the same location and compared them. The crop from the 7D made its version larger, but the following is what I noticed with my very unscientific experiment (partly due to laziness and partly because there are flaws in this test I will not post the crops). Here are two different shots from each shoot, but note that these are not the ones I compared. They won't tell you much about the quality of the cameras but they'll give you an idea of the conditions.
7D - http://500px.com/photo/5118931
5D3 - http://500px.com/photo/6268179
- The 5D3 had a huge advantage in noise. I had taken the 7D shots at ISO 800, while the 5D3 shots were taken at ISO 1600. Nevertheless the 7D had very noticeable noise while the 5D3 was significantly cleaner.
- The 5D3 had far more detail in the shot. I could see far more details in the feathers than the 7D - even when the crop was taken into account.
- The 5D3 seems to have better dynamic range. With the 7D the black parts of the bird were solid black, while with the 5D3 there was a lot more detail there. This may also have been an exposure issue.
When I look at this, I am seeing really no reason to keep the 7D. Other than having two more fps, the 5D3 outperforms it in every aspect - even when the crop is taken into account. Perhaps this may not be true for ISO 100, but for bird photography that is extremely rare.
My question is to those who also have both cameras. What have you noticed in the difference? I am not looking for theoretical discussions here but practical ones from other individuals who have used both cameras.
This is just a single test and ideally I should test both cameras on a tripod with the same subject at the same time, but I am curious if others have noticed the same thing. At this point I am strongly leaning towards selling the 7D and going back to a single body, with the proceeds going towards funding a future 600/4 II.