Canon 7Dii vs 5D Mark iv

[Michael Foster]

Hi all,
I have been agonizing over the purchase of a new body to help improve my photography. I have the 70D now and have obtained some wonderful shots with it but have found a couple frustrating limitations. I am an avid birder who also like photographing what I find. I do not take the approach of going out for a photo of a particular bird, but rather am out looking for birds and like to photograph what I find. So I am not often in a blind or a situation where I can fill the frame with a bird. Much of my photography is really just snapping pics so I can study them to help me with ID of the bird. Taking pics in low light is less than satisfactory with the 70D. I find that getting autofocus is sometimes problematic and noise becomes unacceptable pretty quickly. I have both the 400 5.6 prime and the 100-400 IS 4.5-5.6 ii lenses and use both. Neither lens works with a tele-extender (1.4) except when the scene is quite bright.

I have been looking at the 5D Mark IV pretty hard but I'm thinking maybe the 7D ii might be better for my needs. I am ignoring the costs here, and just focusing on what the camera will do for me. I am thinking the full frame may be not quite fit my needs as I would be losing that 1.6 crop. I find that I am cropping my photos pretty standardly (remember I am shooting with a 400 and not hiding in blinds and the like to get close, but am out actively walking and seeking birds). Sounds like the AF is better on the 7D as opposed to my 70d and the performance is better in low light.

I read a review of a bird photographer who shoots similar to my style in the rain forest. He has standardly used a 7D ii and thought the new Mark IV would perform better in low light and gave it a go. He found that with the need to crop the photo (losing the advantage of the crop sensor) that by the time he had a photo of the bird that he wanted, the difference between the Mark IV and the 7D ii was negligible. He decided to stick with his 7D for now and is hoping for the next generation of 7D to have a few improvements.

I was just wondering what folks here think about the difference between these 2 bodies and if the improvements offered in the Mark IV make it a better choice or if the 7d may still make more sense for me.