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Old Feb 12, 2007, 4:04 AM   #1
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Hi there,
I have a strange problem here... the camera works well with auto ISO adjustment (chooses ISO on it's own in a certain range) WHEN and ONLY WHEN I don't manually under/overexpose.

Is this normal?

Example scenario:
- take a picture, camera chooses f/5.6, ISO800 and I find it a tad too bright, I press the exposure correction button, say -0.3 or -0.7 and aim at the same subject. Camera won't adjust to ISO800, f/4.5 or ISO1600 f/6.5 or the like, or simply go from 1/30 to 1/45 (or the like).

It tries to get ISO200 and tries to adjust exposure and f-stop accordingly... what am I missing here?
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Old Feb 12, 2007, 5:44 AM   #2
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I believe that the exposure is based on an initialISO value of 200 such that when it can no longer open up the lens beyond it's minimum f stop, it then adjusts the ISO up to the maximum setting i.e. 1600.

If you use the exposure correction then it's likely that the ISO will be changed up or down depending upon what limits are still available.

If the maximum ISO been set to 1600 & the exposure is taken at ISO 400, then 1 stop under would set the ISO to 200 & 1 stop over would set it to 800.

If you are using Tv mode, the changing the shutter speed to a slower speed will reduce the ISO to ISO 200 where the optics can then be set by the exposure setting to change the f stop.
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Old Feb 12, 2007, 9:41 AM   #3
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I don't know for sure about the DL2 (sorry) but what you are describing is a very annoying shortcoming of the DS. There's no way around it with the DS. It's probably fixable with a firmware change.
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Old Feb 12, 2007, 1:40 PM   #4
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This is normal, and very expected behavior. Auto ISO tries to give you an exposure which is 'correct' according to camera metering. If you override this, you are telling the camera you don't want its 'correct' exposure, so it does what you tell it to do even if it's 'wrong'.

I'm still dealing with learning curve here myself, but since I am used to fully manual operation, that is what I expect the camera to give me.

brian
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Old Feb 12, 2007, 2:32 PM   #5
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For some reason, it is a common misunderstanding that a camera can't perform exposure compensation with auto ISO. Plenty of other camera models, including my K10D, do this properly. All the camera's computer has to do is move the zero-point that represents proper exposure. There is absolutely no need for the camera to inhibit auto-anything to do this. It just needs to follow its program "line" to the different exposure value. Assuming the DL2 behaves the same way as the DS, the problem described with the DL2 is just an odd limitation in the way Pentax did things.
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Old Feb 13, 2007, 5:46 AM   #6
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Thanks for the responses so far, I too think it's just a Pentax limitation to the "entry level" DL2 which indeed is very annoying.

I thought I was missing something here, but if some of you already know this then it's just crap and :P and here.

Oh well.
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