Optimal Image size

Until we have big storage I would suggest to keep the uploaded max image size on 4k or below
if not needed to show DOF / BQ / Dynamic range / etc.
this will also keep the download speed high if you open an image in fullscreen.

Whats your opinion?

You might take a look at "how to use this side"
You can store images here up to 4MB per file this will change in future.
You will also have gallery in future to manage your uploaded files.
For now you may link them form other post.