I don't usually shoot video but this had me wondering...
This thread seems to indicate that the A7RIII will default to crop-mode for 4k video when APS-C/Super-35 crop mode is in "auto" - supposedly because crop-mode video is of higher quality (see thread for details).
Zayne12 wrote:
No with the r3 it crops for 4k if I remember correctly only the a7sii a9/a9ii and a7iii shoot ff 4k a7s does also but with an external recorder.
That is not correct.
ronno wrote:
Hi all, can’t figure out how to shoot full-frame 4K - Am I missing something, or is it not possible?
best,
Ronno
You need to disable the super 35mode (crop) which is on by default.
A7R2,3 & 4 -almost any high megapixel body benefits from using a crop of the sensor for video.
To capture ~25fps from the full sensor it needs to pixel bin and/or line skip (so throwing away information) and that leads to less fidelity around details.
If they read every pixel in FF mode it would be more like 8K and the processing power just isn't there.
Even if it could, there would be serious heat issues to deal with, Sony cameras already don't do well with long takes.
The actual sensor might have a speed limitation too, I don't know.
For video, if you have one, the A9 is the best, in fact it's superb in FF 4K, no better in S35. The AF is also significantly better too.
