Auto ETTR Timelaps: how to limit ISO?

[Armand9x]

I've been trying to do a day to night Timelapse with Auto ETTR and the intervalometer. My T3i is pretty useless above ISO 800 so I don't want it jumping up above it.

It seems like the auto exposure feature works better, but you can't set it to always be on.

I want to shoot a Timelapse starting in ISO 100 and have it end up at ISO 800 at night.

[chris_1975]

the auto ISO Limit in Canon Menu ....

[Armand9x]

Thank you! I'm glad it was something easy...

[dmilligan]

I can't think of a good reason to limit ISO, it defeats the whole purpose of "Expose to the Right" and goes against the concept. If you want less noise then you should use a higher ISO, not limit yourself to a lower one. That would be exposing to the left.

Somewhat counterintuitively, higher ISOs actually have less noise per photon (and if this wasn't true, then there would actually be no reason for ISO to even exist, think about it). Once you have reached your maximum shutter speed it's better to continue increasing ISO rather than under-exposing the shot.