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Bug report? a2500

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Offline Eildosa

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Bug report? a2500
« on: 20 / July / 2014, 16:56:35 »
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Hello,

I got CHDK working today for my a2500 and I did some test.
It seems that tv and/or ISO override do not work when the flash is forced (tv and iso forced by chdk, flash forced by the camera menu)





Is this because the flash is adapting it's power to my override or is this a bug?
Thanks.
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Offline waterwingz

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Re: Bug report? a2500
« Reply #1 on: 20 / July / 2014, 17:05:05 »
Looks pretty normal to me. 
In your pictures,  the Tv and ISO are where you set them - when the flash fires, they are by chance the right settings.  When the flash does not fire,  the pictures are underexposed.

Seems pretty consistent to me.  Am I missing something ?

p.s.  You really are not getting ISO 10 though - lower limit is usually about 80.
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Ported :   A1200    SD940   G10    Powershot N    G16
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Offline srsa_4c

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Re: Bug report? a2500
« Reply #2 on: 20 / July / 2014, 17:08:45 »
Quote from: Eildosa on 20 / July / 2014, 16:56:35
It seems that tv and/or ISO override do not work when the flash is forced (tv and iso forced by chdk, flash forced by the camera menu)

The duration of flash is probably shorter than the shortest exposure time used here. Try repeating the same test in daylight, outside.
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Offline waterwingz

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Re: Bug report? a2500
« Reply #3 on: 20 / July / 2014, 17:26:29 »
Quote from: srsa_4c on 20 / July / 2014, 17:08:45
Quote from: Eildosa on 20 / July / 2014, 16:56:35
It seems that tv and/or ISO override do not work when the flash is forced (tv and iso forced by chdk, flash forced by the camera menu)

The duration of flash is probably shorter than the shortest exposure time used here. Try repeating the same test in daylight, outside.
I see what you mean now.  And srsa_4c's answer makes perfect sense too.
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Ported :   A1200    SD940   G10    Powershot N    G16
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Offline Eildosa

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Re: Bug report? a2500
« Reply #4 on: 20 / July / 2014, 17:28:18 »
Well I was expecting the same underexposure effect as I increased shutter speed.
But as srsa_4c said it, flash duration is faster than my faster shutter speed.

I did not know that. I was expecting it to be 1/25 or something like that.

One other question then, I did the same thing while disabling chdk override. the camera took a picture with
ISO 320, tv 1/60 and flash (the same picture).
And it looked less exposed than my chdk pictures.
What kind of magic is that? post processing?
« Last Edit: 20 / July / 2014, 17:30:21 by Eildosa »
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