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extra long exposures (split from: Hardcore modding on a A530, thanks to CHDK!

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confirmed!
64 sec ok
128 sec ok
*aperture override=16. The A590IS hardware aperture limit is 11 if i'm not mistaken.

I will try more (with longer shutter speed) later. The processing time is very long though.

update : 512 sec is working.

i wonder how long actually it can go and whether is save or not to use it

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Offline reyalp

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update : 512 sec is working.

i wonder how long actually it can go and whether is save or not to use it
This has been asked earlier in the thread, and the consensus is, we don't know :)

Which canon firmware is your 590 ?

edit:
From a code testing point of view, if 128 sec works then the change is working.

edit again:
I see 101b in the other thread. As soon as someone verifies 100e, I can check this in.
« Last Edit: 09 / June / 2009, 18:50:53 by reyalp »
Don't forget what the H stands for.

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Offline mngc

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  • a590is fw 1.0.1b & sx110is fw 1.0b
Now the medium test on a590is, fw 1.0.1b

Extra long exposure working, but have some problems.

16,32,64,128,256 sec ok.

But 3belas, 512 sec NOT ok.  Recording time ok, 512 second (i disabled the dark frame subtraction, to speeedup the test). My original goal the picture quality check (noise, hot pixel, etc.). Lower exposures correct, the image bright and brighter. But with 512 sec the image black. Totaly black, i check with picture viewer, RGB= 0,0,0. I use 230Volt adapter for power the camera.

Test around 512sec:
322sec OK
406sec OK
420sec OK, enum type changed
440sec OK, enum type changed
450sec OK, enum type changed
470sec X  , enum type changed
512sec X
645sec X


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Offline reyalp

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Camera limit maybe, nothing in our override code knows the difference between 470 and 512.
Don't forget what the H stands for.

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Offline mngc

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  • a590is fw 1.0.1b & sx110is fw 1.0b
For another cameras users with extra long exposures (not a590is fw 1.0.1b) ok with 512 sec?

@3belas, your 512sec picture totally black or no?

Camera limit maybe, nothing in our override code knows the difference between 470 and 512.

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Offline fudgey

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  • a570is
For another cameras users with extra long exposures (not a590is fw 1.0.1b) ok with 512 sec?

I believe I tested my a570 100e up to 600 seconds (worked fine, DFR enabled if I'm not mistaken).

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Offline mngc

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  • a590is fw 1.0.1b & sx110is fw 1.0b

I believe I tested my a570 100e up to 600 seconds (worked fine, DFR enabled if I'm not mistaken).

Thanks, your test. I not understand "DFR enabled" what is this?

@reyalp

I think the camera has a second software or hardware timer with unkown fuction, which is kill the real picture, and somehow fill image with zero. Main cycle, the recording time always ok, i try enable dark frame subsraction with 512s. The time is ok, 512 * 2sec. But picture again fully black.  Any information on hardware available (shematics, chip datasheet, or chip type?). I have knowledge to electronics. You can attach the software patch? I interest. (please note, i am not expert in assembly, and CHDK). How the patch working (simplified)? Canon has a hardware or software timer, and check or count timer owerflow(s)? 

460s working properly, this is great. The picture is noisy and have many hot pixels. This is normal, with extra large exposure time and small CCD sensor. This is not fatal error. Requies many set of picture and averaging it. And requies a master dark frame (average set of dark frame). CHDK has function to record set of dark frames without normal picture? Or options to create two picture (one normal picture, and one dark frame)? Hardware way to record dark frame, the lens cap, and record normal picture. But the optical mechanics i think very soft.   


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Offline reyalp

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I believe I tested my a570 100e up to 600 seconds (worked fine, DFR enabled if I'm not mistaken).

Thanks, your test. I not understand "DFR enabled" what is this?

@reyalp

I think the camera has a second software or hardware timer with unkown fuction, which is kill the real picture, and somehow fill image with zero. Main cycle, the recording time always ok, i try enable dark frame subsraction with 512s. The time is ok, 512 * 2sec. But picture again fully black.  Any information on hardware available (shematics, chip datasheet, or chip type?). I have knowledge to electronics. You can attach the software patch? I interest. (please note, i am not expert in assembly, and CHDK). How the patch working (simplified)? Canon has a hardware or software timer, and check or count timer owerflow(s)? 
We basically just override the function that sets exposure time. To do this, we have to hook expdrvtask and copy the code up to the point where we change it (apex2us)

patch http://www.zshare.net/download/612200006af1558d/

CHDK doesn't let you create dark frame directly. This can be done, but it hasn't been implemented in CHDK. Cover the camera or use a blacked out box, bag etc.
Don't forget what the H stands for.

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Offline yvesson

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Hej,
Would it be possible to record the pic before the dark frame is taken, mostly for testing purposes ?

Just curious, why 10 min exposure (with prolly very bad results) could be usefull ?

 

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