Auto ISO#16

Ability to have auto ISO in manual mode. It might sound contradictory to have an auto setting in manual mode, but this is a great feature supported by my Nikon DSLR.

We would love to make ISO and Shutter Speed completely independent of each other (so that you can set ISO to “Auto” and Shutter Speed manually), but I believe this isn’t possible on the iPhone. Apparently, as soon as ISO or Shutter Speed are set manually, the other also becomes manual by default and can’t be set to “Auto”. If I’m not mistaken, this is also the case in other camera apps like ProCamera, Moment, and Halide.

@Florian - can you confirm whether I’m right about this limitation?

It is possible to have shutter AE. The apps Firstlight and 645 Pro both have auto iso with selectable shutter speeds.

@Mark Robertson Thanks for the pointer - you’re right, I just tried it in Firstlight! We’ll investigate.

This may help

the Ricoh GR has this feature build in. I loved it. A kind of semi-automatic. You could fix for example shutter speed and ISO and aperture adapted automatically.

yeah, it could involve adjusting the other setting manually under the hood according to an exposure meter read out. Opencv probably has an implementation that could work. I’m not sure about a native implementation though.

This is a work around, but you could pull a frame in with the auto setting and just do an exposure match with the manual settings. That would be a lot easier than building metering from the ground up and would blend more seamlessly with the native light meter for user experience. Less engineering time is always nice.

You could also just take a grid of pixel samples across the input image and use those as reference for adjusting settings that create the new one. It would be more efficient to process.

Auto ISO in “manual” mode is an extremely useful function.
Really the best of all worlds. I’m a 40+ year pro shooter and use this 90% of the time now that higher ISO is usable.

I guess the correct way to say “Auto ISO” would be Priority mode, isn’t it?

Auto ISO is used only to auto adjust the ISO while in manual mode and on a traditional camera this is the implementation - it generally does not involve using any priority mode.

It allows a user to fix both the aperture and shutter speed while alowing the ISO to fluctuate so that they retain creative control without having to worry about exposure.

Traditionally Priority mode only fixes a single point of the exposure triangle, either aperture or shutter speed while letting the other two points fluctuate.

Given that the phone apertures are fixed though, aperture is taken out of this equation. When you only have shutter speed and ISO to work with and you are setting the ISO to auto then auto ISO and shutter priority are the same thing for a phone in reality and I believe that’s why the issue was merged with shutter priority. Implementation wise on a phone they are the same.

Ohh, I get it, thanks for the explanation Ryan (: