Hi,

My intentions for now are still photography of perched birds in good and low light conditions at 15-35 yards. My intensions are not to make large prints of stills. I find sharp RAW files in low light situations a necessity.

I read several reviews of Canon EOS DSLRs for my equipment selection, i.a.:

- BirdPhotographers.net findings about the Canon 7D Mark II, 5D Mark III and IV, 1D X Mark II;

- A comparison of the Canon 7D mark II AF system with 1D X and 5D Mark III:
http://www.the-digital-picture.com/C...omparison.aspx

- An impressive field test of the Canon 1D X Mark II:
http://arihazeghiphotography.com/blo...-field-review/

- A limited comparison of the Canon 1D X Mark II and Nikon D5:
https://www.dpreview.com/reviews/can...d-x-mark-ii/15

- Worries about the buffer capacity of the Canon 5D Mark IV:
http://www.birdphotographers.net/for...OS-5D-Mark-IV?

- Worries about rolling shutter of the Canon 5D Mark IV:
https://www.dpreview.com/news/705700...g-shutter-test

Rolling shutter of the Canon 5D Mark IV and 1D X Mark II:
https://www.youtube.com/watch?v=wXSqKX3OexQ

In practice equipment advice asked (continued): please correct the underneath findings if they’re false:
- the Canon 7D Mark II with a Canon telephoto lens 100-400mm f/4.5-5.6 has soft/non-sharp RAW files in low light situations;
- the Canon 5D Mark III and 1D X Mark II have sharp RAW files in low light situations. I could not find a comparing field test showing that the Canon 1D X Mark II over classes the 5D Mark III in (extreme) low light situations;
- The Canon 5D Mark III has (some) luminescence noise (non-colored) in (very deep) shadows;
- the Canon 1D X Mark II is excellent for BIF, long distance still photography, bird photography with extenders;
- the Canon 5D Mark IV and III can handle the same relevant Canon lenses and Usable AF Points for bird photography, based on the 5Dmkiv, 5Dmkiii, 1DXmkii instruction manuals! Relevant lenses for bird photography are the Canon 400mm f/4 DO IS II USM, 500mm f/4L IS II USM, 600mm f/4L IS II USM.
- the RAW dynamic range of the Canon 5D Mark IV is expected to be improved, but a comparing field test should show;
- Non-theless the equipment, skills are as important.

Former findings are meant for my purpose/equipment selection and not for disqualifying a DSLR in general.

Best regards,
Jack