Is or when will h.265 be implemented. If it was how do turn it on?

This is outside Zenphoto's domain but dependent of what the visitor's browser respectively the vistor's system supports.

I think if you want to deal with video, it's more likely to prefer the AV1 format. It's not encumbered by patents, it's a newer format, and it has more support in browsers.

Check out:
https://caniuse.com/hevc
https://caniuse.com/av1

The support for those far from great. So h264 / standard m4v is still the best to cover most visitors. Zenphoto does not suppprt hevc or av1 for those for that reason.

Besides the best for videos are video services like youtube as they can adjust the video size to the visitors speed and devices accordingly.

Just to clarify, if you use mp4 videos with hevc which is h265 and the vistor's system supports it, it should work. .av1 videos we don't support but we consider to allow the suffix in the core video class so it will work when it works.

The support for those far from great. So h264 / standard m4v is still the best to cover most visitors. Zenphoto does not suppprt hevc or av1 for those for that reason.

The AV1 codec is not supported in Edge browser (5% of the market, after installing the plug-in from MS Store the videos work), Safari (6%) and IE (0.4%).

So for 94% of users the videos work... and are typically 30-50% smaller than the H.264 codec. I would use it!

And this might just be a small step towards AV1 becoming more widespread on the internet as well.

Beside that also the OS on the visitor device counts: As long as you save them with .m4v or .mp4 file they probably would work already if the browser can play them (yes, I know that they are not mpeg 4 at all).

hevc being mpeg should also work with mp4/m4v (if it can be played).