1.8X 4K crop mode. too good to be true for recording bird?

John Sheehy wrote:

Markr041 wrote:

1. John Sheehy wrote:

pawn wrote:

I saw the same for R7: https://sg.canon/en/consumer/eos-r7-body/product

Is there a catch in video quality?

Same as using a smaller sensor area with less pixels for stills, and all the caveats that go with that.

Not quite. The resolution cropped or not is 4K.

Yes, but the source # of pixels creating the 4K output varies. So, the question is basically the same as 4K JPEGs from various sensor crops, as far as estimating noise, DOF, angle of view, etc.

For stills, the resolution goes down in cropped because the number of pixels is reduced. 4K is 4K, just taken from a smaller part of the sensor. Moreover, in non cropped 4K, unless in fine mode, the 4K is achieved via line skipping from the full sensor. This results in artifacts in the full-sensor 4K. The cropped 4K does not have these artifacts and is thus crisper. There is slightly more noise due to the reduced sensor size for cropped 4K.

The question was about 1.8x crop mode vs using the entire sensor within the 16:9 rectangle. I was originally going to mention the line-skipping scenario myself, but edited it out before replying, because I thought I was getting too deep in the weeds for the OP's question.

I agree that 4K jpeg stills cropped and not cropped are analogous to 4K video cropping.

But your original post omitted the 4K. You just said jpegs. Most stills shooters compare full pixel to cropped pixel, so as most people in this forum are stills shooters, that omission is likely to confuse.