Author Topic: how to set max iso for auto iso of 500D(PROP_AUTO_ISO_RANGE?)  (Read 5256 times)

dimchang

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how to set max iso for auto iso of 500D(PROP_AUTO_ISO_RANGE?)
« on: August 08, 2012, 08:54:18 PM »
i want to write a function to set the max iso(maybe 400) for auto iso range of 500D.
and i see a property "#define PROP_AUTO_ISO_RANGE     0x8000003b // len=2, LSB is max iso, MSB is min iso (ignored?)"
How to use this property to set the max iso?

if can not use this property, any idea to set the max iso?
thanks in advance:)

miyake

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Re: how to set max iso for auto iso of 500D(PROP_AUTO_ISO_RANGE?)
« Reply #1 on: August 09, 2012, 08:46:36 AM »
it's a memory address for PROP_AUTO_ISO_RANGE variable.
See the last line of src/propvalues.c . it defined "int auto_iso_range = 0x4868;" on 500D.
Because 500D has no PROP_AUTO_ISO_RANGE in canon menu.
and using this value in shoot.c .
But only to use Bulbramp or HDR.

I guess,
 - add menu item to setup max iso value on ML menu
 - enable Live View auto iso ML function(currently disabled now may be.)
  - use auto_iso_range value  in LIveVIew audo iso

So you may read these codes.Actually, I don't know this is working or not.



miyake

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Re: how to set max iso for auto iso of 500D(PROP_AUTO_ISO_RANGE?)
« Reply #2 on: August 09, 2012, 09:11:37 AM »
Found it.
shoot.c : 4576
LiveView auto iso is disabled because unstable.
So you may change "if 0" to "if 1" on your own build.
Then you can use LiveView auto iso and you can set min/max iso values on your 500D, may be.
I'm not check it. So please check you can use it or not.

dimchang

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Re: how to set max iso for auto iso of 500D(PROP_AUTO_ISO_RANGE?)
« Reply #3 on: August 09, 2012, 12:18:22 PM »
it's a memory address for PROP_AUTO_ISO_RANGE variable.
See the last line of src/propvalues.c . it defined "int auto_iso_range = 0x4868;" on 500D.
Because 500D has no PROP_AUTO_ISO_RANGE in canon menu.
and using this value in shoot.c .
But only to use Bulbramp or HDR.

I guess,
 - add menu item to setup max iso value on ML menu
 - enable Live View auto iso ML function(currently disabled now may be.)
  - use auto_iso_range value  in LIveVIew audo iso

So you may read these codes.Actually, I don't know this is working or not.
hi, miyake, seems the code in line 4576 of shoot.c is only for movie mode.
my thinking is, when i take a picture with auto_iso selected,
ML will check if actual iso is greater than 400, then set the ISO to 400(camara will re-calculate the shutter).
and after picture taken, set ISO to auto again.

Is it achievable?
BTW, miyake, i use your VM to set up my environment, thank you ;D

miyake

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Re: how to set max iso for auto iso of 500D(PROP_AUTO_ISO_RANGE?)
« Reply #4 on: August 09, 2012, 04:13:09 PM »
Ah, you want to use in still mode. I see.


Actual code is in movtweak.c:4083 update_lvae_for_autoiso_n_displaygain() func.
this func has some limitation(except 500D and is_movie_mode()). So you need to delete some limitation and build your own version.

One more thing.
movtweak.c:4083 is calling update_lvae_for_autoiso_n_displaygain() but disabled it. You also comment out this line.
Anyway, try to delete any limitations , then you can get auto-iso mode on still mode I guess.

It's my concern. But it's not guaranteed. Try it.

P.S. What time did you need to download VM image from my server in Japan?  I think VM approach is good to noob developper. But my server is located in Japanese, So I think too much time needed to download from European users.


dimchang

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Re: how to set max iso for auto iso of 500D(PROP_AUTO_ISO_RANGE?)
« Reply #5 on: August 10, 2012, 04:56:23 AM »
anyway, i made it :)
i added a submenu and write some code in lens.c to limit the max auto iso.
PS, my download speed is around 400Bps, but i am not in Euro, i am in China.

miyake

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Re: how to set max iso for auto iso of 500D(PROP_AUTO_ISO_RANGE?)
« Reply #6 on: August 10, 2012, 05:57:16 AM »
Good.
Does it working fine? and Does your code help a lot of 500D users?