X100 - Strange choice of ISO and Shutter Speed

Discussion in 'Fuji X100 Forum' started by Crsnydertx, Jul 3, 2012.

  1. Crsnydertx

    Crsnydertx SC Top Veteran

    Jan 21, 2011
    Houston, TX
    Real Name:
    Okay, full disclosure first: I've never really tried to fully grasp the settings on my X100. I've used some of the setup information listed on this forum, but I've never tried to understand the "whys"; maybe now I'll start that process.

    Anyway, this morning I set out to take a few test photos of the local wetland and waterway; terminology here is a "bayou". Bright but hazy sunshine, broken clouds, around 9 am Central Time in Houston. Not great conditions, but I had a deadline. I had the camera set to Auto ISO, Aperture priority, and selected aperture f/5.6. So I frame and half-press the shutter - and the camera chooses ISO 800 and shutter speed 1/2500 second! Why would it do that? What settings have I chosen that would force both ISO and shutter speed upscale, where there was plenty to work with at normal ISO?

    I tried a few times and kept getting these unusual settings, then gave up on Auto ISO and switched that off. Thereafter, no problem with operation.

    I'm sure it's some misunderstanding of settings on my part. Anyone have an idea what I need to change?

    Thanks in advance.
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  2. Julien

    Julien SC Top Veteran

    Jan 6, 2012
    Paris, France
    Real Name:
    Probably you have the Dynamic Range thing on "AUTO DR" or "400% DR". You should select "100% DR" explicitly to prevent the camera from tweaking the DR on its own (as the X100 uses the ISO sensitivity to achieve that result). The explanation of all this is in a thread here somewhere if I recall correctly. I'll see if I can find it.
    • Like Like x 3
  3. Ray Sachs

    Ray Sachs SC Legend

    Sep 21, 2010
    Not too far from Philly
    Real Name:
    you should be able to figure it out...
    Yeah, it needs to shoot at a minimum of ISO 400 for DR at 200% and ISO 800 at DR 400%. So if you have it set to 400% or to Auto DR, it'll almost always bump the ISO to 800 in conditions like you were in. The good news is the files are so clean at 800 that its generally worth doing because the higher DR settings really work quite well. This is all for jpeg, though. If you're shooting raw, you really ought to set your DR at 100% unless you really want to get into the vagaries of push/pull processing - it will still bump the ISO in raw but obviously won't compensate with the appropriate processing after the fact so you'll get some weird results until and unless you figure out how to process them appropriately. But for shooting jpegs, in daylight conditions I generally leave it on Auto DR and either use auto ISO also or I use an ISO 800 or above...

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  4. Boid

    Boid SC All-Pro

    Dec 15, 2011
    Bangalore, India
    Real Name:
    Thanks! I didn't realize this was what was happening and it was driving me up the wall.
  5. Glyn

    Glyn SC Regular

    Jul 14, 2012