Dual ISO, dynamic range improvement - General Discussion and Assistance - CHDK Forum

Dual ISO, dynamic range improvement

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Offline dvip

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Dual ISO, dynamic range improvement
« on: 17 / July / 2013, 12:06:17 »
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I wonder if this is possible using a small sensor:

http://www.magiclantern.fm/forum/index.php?topic=7139.0


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Offline philmoz

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Re: Dual ISO, dynamic range improvement
« Reply #1 on: 17 / July / 2013, 15:47:04 »
I wonder if this is possible using a small sensor:

http://www.magiclantern.fm/forum/index.php?topic=7139.0

Unlikely as it requires two, independently configurable, amplifier circuits between the sensor and ADC.
If Canon has only done this on the 5DIII and 7D DSLR's I doubt we would see this on any P&S.

Phil.
CHDK ports:
  sx30is (1.00c, 1.00h, 1.00l, 1.00n & 1.00p)
  g12 (1.00c, 1.00e, 1.00f & 1.00g)
  sx130is (1.01d & 1.01f)
  ixus310hs (1.00a & 1.01a)
  sx40hs (1.00d, 1.00g & 1.00i)
  g1x (1.00e, 1.00f & 1.00g)
  g5x (1.00c, 1.01a, 1.01b)
  g7x2 (1.01a, 1.01b, 1.10b)

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Offline ursamajor

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  • SX150IS, SX510HS
    • Per aspera ad astra...
Re: Dual ISO, dynamic range improvement
« Reply #2 on: 19 / May / 2016, 13:37:14 »
Indeed in 2013 DualISO worked only on 5D. Now it is supported by much many cameras. CHDK still not support something similar to improve not necessarly DR but the noise? Just asking...  :D

PS: it would be a dream come true, a charming one.  :xmas
SX150IS (retired) :D, SX510HS

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Offline koshy

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Re: Dual ISO, dynamic range improvement
« Reply #3 on: 04 / May / 2021, 19:36:12 »
Forgive me for necromancing this thread, but I was just playing with the dual ISO stuff on a 5D Mk II in previous weeks and it is very interesting. I think I love it, I shot at ISO 800 +1EV with a ISO 100 secondary for highlight recovery.
I didn't look at its requirements in terms of hardware in detail but noticed that its implementation changed sometime to encompass more DSLRs. Was what phil summarized the end of it
Unlikely as it requires two, independently configurable, amplifier circuits between the sensor and ADC.
If Canon has only done this on the 5DIII and 7D DSLR's I doubt we would see this on any P&S.
Or did it become possible for any CHDK camera?

Well, not any I guess; anything newer than the Ixus 980 990 can hardly be used properly for RAW shooting due to the geometric distortion correction fix or rather lack thereof. But for those select few, already having a 12 bit AD/C and not yet having lens designs favoring field curvature over astigmatism (as the former is easily corrected if you have the computational power) I do second this:
it would be a dream come true, a charming one.  :xmas
Koshy had a little ELPH which wasn't white as snow but everywhere that Koshy went the ELPH was sure to go. (actually an SD, but that detail ruins the rhyme...)


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Offline Ant

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Re: Dual ISO, dynamic range improvement
« Reply #4 on: 05 / May / 2021, 02:44:02 »
Or did it become possible for any CHDK camera?
It possible only for some cameras with canon's APSC sensor.

https://chdk.setepontos.com/index.php?topic=12754.msg136098#msg136098


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Offline koshy

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Re: Dual ISO, dynamic range improvement
« Reply #5 on: 29 / May / 2021, 08:20:40 »
Or did it become possible for any CHDK camera?
It possible only for some cameras with canon's APSC sensor.

https://chdk.setepontos.com/index.php?topic=12754.msg136098#msg136098

Thanks a lot for the pointer Ant. Very interesting. Turns out I made a mistake in my thinking that is common for me I guess. As I have done so much with cameras that cannot shoot RAW natively - I ignored all those supported by CHDK that can. Perhaps I should look for a used M3 in good condition and for little money, if I do it'll find me eventually.
Koshy had a little ELPH which wasn't white as snow but everywhere that Koshy went the ELPH was sure to go. (actually an SD, but that detail ruins the rhyme...)

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Offline Ant

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Re: Dual ISO, dynamic range improvement
« Reply #6 on: 29 / May / 2021, 10:06:31 »
Perhaps I should look for a used M3 in good condition and for little money, if I do it'll find me eventually.

Not sure about M3: there is a problem with interpolation of focus pixels in dual iso mode. Maybe it's better to choose a camera with dual-pixel sensor. But AFAIK there are no CHDK ports for it.
« Last Edit: 29 / May / 2021, 10:09:53 by Ant »

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Offline koshy

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Re: Dual ISO, dynamic range improvement
« Reply #7 on: 29 / May / 2021, 13:16:39 »
Not sure about M3: there is a problem with interpolation of focus pixels in dual iso mode. Maybe it's better to choose a camera with dual-pixel sensor. But AFAIK there are no CHDK ports for it.
Thanks for that pointer as well. From what I read the PowerShot G1 X Mark III was the first compact with a dual-pixel sensor and that is fairly recent although still Digic 7. The M100 seems to have one, too and there is an effort going on doing something with it. I'll lean back and watch what happens on this matter. Still interesting.
Koshy had a little ELPH which wasn't white as snow but everywhere that Koshy went the ELPH was sure to go. (actually an SD, but that detail ruins the rhyme...)


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Offline Ant

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Re: Dual ISO, dynamic range improvement
« Reply #8 on: 29 / May / 2021, 13:41:00 »
From what I read the PowerShot G1 X Mark III was the first compact with a dual-pixel sensor and that is fairly recent although still Digic 7.

There need to look inside the firmware dump to be sure that the sensor is compatible with dual iso.

 

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