ISO settings, and other ramblings

FingerPainter wrote:

ahaslett wrote:

Auto ISO would be my default setting for walkabout. For more considered shooting off a tripod, I would like to make my own choices, not least between DR, shot noise, read noise and highlight posterisation.

Andrew, can you give some examples of how Auto ISO would result in a worse outcome in such shooting situations than would using an autoexposure mode without Auto-ISO? Since you're on tripod I presume you are not talking about situations where you'd be using flash or where the metering solution is changing rapidly despite constant light.

I can think of several reasons not to use an autoexposure mode, but I have a hard time coming up with a situation where using an autoexposure mode without Auto-ISO looks worse than autoexposure mode with Auto-ISO.

Andrew

... and posters on DPR

Truth is a jewel with many facets. Ursula K LeGuin

I would start by deciding what exposure time suited the scene, especially if water is involved.  Then I would decide whether I need a stopper filter at base ISO.  Then I would think about WB.

Typically you can shoot landscape at base ISO and let the exposure be decided by using the histogram to ETTR using EC.

If the scene was poorly lit and had limited DR or you need a limited exposure time, then I would bump ISO to reduce shadow read noise within the native range for an ISO variable gain camera.  If you have dual gain switched capacitance, you want to maximise DR by shooting above the switch rather than just below it.

In other words entirely scene and composition dependent.

If running around in a social setting then just bang on Auto-ISO and Auto-WB and get on with it.

It may be that Auto-ISO would do as good or better job but I would rather think it through.  I can't be bothered to learn how Auto-ISO works across different cameras.  Anything that slows you down when composing landscape is good.

Andrew