Multiplication factor for Custom AutoISO and A720

dbookbinder

Multiplication factor for Custom AutoISO and A720

« on: 30 / April / 2008, 21:02:24 »

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I installed Build 50 on my A720 and am customizing the AutoISO. It appears that, although the screen says it is multiplying by 10 the numbers I enter for maximum and minimum AutoISO and AutoISO Hi, actually it is multiplying them by 16. So, to set a maximum ISO of 400, I enter "25" rather than "40" and if I want ISO 50 for the minimum value I enter "3" rather than "5." Is this a peculiarity of this build, the camera, or both? Not really a problem, since it's easy enough to get the values I want, but I'm curious to know why the factor is 16 instead of the indicated 10.

Thanks,
David

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mkmenuts

61
SD700 (1.01b)

Re: Multiplication factor for Custom AutoISO and A720

« Reply #1 on: 03 / May / 2008, 14:10:10 »

Actually, it is multiplying by 10. The numbers you set are real-iso, whereas the numbers you see later are market-iso.

Turn on display of both via chdk to see how it works.

mkmenuts

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dbookbinder

Re: Multiplication factor for Custom AutoISO and A720

« Reply #2 on: 04 / May / 2008, 09:46:25 »

Okay, got it. I was looking at the camera's ISO display, not the CHDK "Miscellaneous Values" display. The camera display doesn't seem to agree with either the "real" or the "market" values CHDK shows!

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laqui

Re: Multiplication factor for Custom AutoISO and A720

« Reply #3 on: 08 / August / 2008, 20:08:43 »

Quote from: mkmenuts on 03 / May / 2008, 14:10:10

Actually, it is multiplying by 10. The numbers you set are real-iso, whereas the numbers you see later are market-iso.
Turn on display of both via chdk to see how it works.
mkmenuts

I've a S5 and set the following AUTO-ISO values:
ISO-HI: 400 (40*10)
Max. AUTO-ISO: 120 (12*10)
Min. ISO: 80 (8*10)
However, e.g. the "market" value shows an AUTO-ISO of 200, the real ISO (I-R) shows 130, and the ISO shown in the picture info is 125. Confused?
Thankx.
Laqui.

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