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Auto ISO Behavior

Started Jul 22, 2021 | Questions thread
DirkPeh
DirkPeh Contributing Member • Posts: 520
Re: Auto ISO Behavior

Erik Baumgartner wrote:

DirkPeh wrote:

frostyj75 wrote:

Hello all, I have been using auto ISO here and there to see what all the fuss is about. I have been really pleased with it and generally top the ISO out at 6400. I have found that it appears to raise the ISO before it raises the shutter speed. When I have my 23mm on, I have the settings at Base ISO - 200, ISO Limit - 6400, and shutter at 1/60th. In bright daylight, the shutter will stay at 1/60th and the ISO will be up over 1000 at times. Isn't the ISO supposed to stay at the base and only raise when the shutter is at the limit?

Am I not understanding how auto ISO is supposed to work? It is very frustrating, thinking that I'm going to get a certain SS and then notice the ISO has gone up instead of the shutter. I end up going back to manual ISO, I'm just wondering if there is something I am missing in the equation.

Thanks!

Jeff

My X100V shows the same behaviour. In bright daylight with correct metering - mostly pattern - it raises the ISO to values up to 1000 or even higher, sometimes with a higher Aperture up to 6400. I've set the min. shutter speed to 1/80.

Can you show an example of this with the exif intact? The only time the ISO should be above base is if the shutter speed has bottomed out or your DR mode requires ISO 320 or 640 to function.

I come from a Ricoh GR III that most of the times will select an ISO of 100 or 200 in comparable situations.

I take pictures in Aperture Priority, the ISO is set to Auto, DR to Auto and I control the shutter speed as part of the Auto Iso setting.

I've read the replies of other users, too. The high ISO value isn't just shown while shooting, it is in the exif data of the photos.

Just one example. Look at the sky, it wasn't the brightest sky ever, but sunny. The Aperture was very narrow, like F11, but nonetheless, the Ricoh did chose much smaller ISO values on a rainy day.

Berlin, Potsdamer Platz Fuji X100V. SS 1/80, F11, ISO 1250!

This is just a few meters away, taken with a Ricoh, it wasn't nearly as sunny. I've used a high contrast bw preset, that could be misleading:

Ricoh GR III, shutter speed 1/200, F9, Iso 200

I've edited my post and added the pictures. The exif is there. The Auto-Iso setting is. IS0 160 up to 6400, the SS is 1/80. The settings on the Ricoh are identical. The DR was set to 100 on the Fuji. I only have the Fuji since a week, so I can't rule out that I make a mistake in the settings, but I don't know what should cause this behaviour.

 DirkPeh's gear list:DirkPeh's gear list
Panasonic LX10 Ricoh GR III Fujifilm X100V Sony a6400 Sony E 50mm F1.8 OSS +5 more
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