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

yvesson

209
A540 SX10IS

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

« Reply #160 on: 06 / September / 2009, 07:15:32 »

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Hej,
I havn't tested more than 1024s on A540, which was already 34 mins of work for my poor sensor, I guess pushing it too far might be a problem for the batteries or for the sensor heat.
And really, the picture is crappy enough at 1024s.

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fudgey

1705
a570is

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

« Reply #161 on: 06 / September / 2009, 08:17:03 »

Quote from: RaduP on 06 / September / 2009, 01:41:49

Ok, I think I found a bug :/
On my a570is, for really long exposures (over 2700 seconds, possibly less) the camera will freeze with a blank screen. No buttons work, including the power button.
Can someone please confirm this?

The longest I've tried on my a570 100e was 1200 s (20 minute exposure + 20 minute dark frame). It worked fine.

You've probably just hit a limit, not a bug. It may or may not be possible to get past that one too if you find out why it freezes, and it could be that it doesn't always freeze... But when does it freeze? I didn't try waiting for this, but at least a 2800 second exposure seems to start fine on my cam. The only button that works during exposure is the battery lid detect switch...if your camera beeps when you touch it, it probably hasn't crashed totally.

(btw, fw version matters a lot in potential bugs considering extra long exposures because each version needs their own asm hack copy pasted from disassembly).

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ewavr

1057
A710IS

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

« Reply #162 on: 06 / September / 2009, 12:37:25 »

Quote from: RaduP on 06 / September / 2009, 01:41:49

On my a570is, for really long exposures (over 2700 seconds, possibly less) the camera will freeze with a blank screen.

Signed int limit=2^31-1 microseconds = 2147s
Unsigned int limit 2^32-1 microseconds = 4294s

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RaduP

926

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

« Reply #163 on: 06 / September / 2009, 14:00:14 »

Quote from: fudgey on 06 / September / 2009, 08:17:03

You've probably just hit a limit, not a bug.

Oh, I used the term bug because on the CHDK camera features the long exposure for the A570is was marked as infinite.

Quote

But when does it freeze?

I think (but am not 100% sure) that it freezes when it does the dark frame. For example, I tried a 2 hours exposure, and checked the camera every once in a while. I didn't look at the clock, but after about a hour the camera LED were still blinking, so it wasn't frozen.

Quote

I didn't try waiting for this, but at least a 2800 second exposure seems to start fine on my cam.

Yes, it always starts fine, the problem is the ending

Quote

The only button that works during exposure is the battery lid detect switch...if your camera beeps when you touch it, it probably hasn't crashed totally.

Normally, the camera LED blinks while taking the long exposure photo. When it starts doing the darkframe the camera will go back to the CHDK interface and have a "busy" message (if it doesn't lock).

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RaduP

926

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

« Reply #164 on: 06 / September / 2009, 14:01:26 »

Quote from: ewavr on 06 / September / 2009, 12:37:25

Signed int limit=2^31-1 microseconds = 2147s
Unsigned int limit 2^32-1 microseconds = 4294s

Hmm.. so what is used? Signed or unsigned? And can this limit be increased, by using some other unit?

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ewavr

1057
A710IS

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

« Reply #165 on: 06 / September / 2009, 15:33:45 »

Quote from: RaduP on 06 / September / 2009, 14:01:26

Hmm.. so what is used? Signed or unsigned?

I don't know. At least you can change in generic/wrappers.c int apex2us(int apex_tv) to unsigned int apex2us(int apex_tv) and try 2700s again...

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mngc

113
a590is fw 1.0.1b & sx110is fw 1.0b

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

« Reply #166 on: 07 / September / 2009, 06:20:31 »

questions to expert users

My camera is a590is fw 1.0.1b. The maximum working extra long exposure time is 460 sec, more time ok, but the picture totally dark. Any idea, bug or camera limit?

Possibly add option to chdk to record only dark frame? One dark frame not enought. Master dark frame requied. Of course, manually i can create this, but useful feature from script.

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RaduP

926

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

« Reply #167 on: 07 / September / 2009, 15:46:18 »

You can record the darkframe by yourself.
What I did was select f/11, then go to a place with low light, put the camera screen down, and then put something on top of it (some lid that is black). Then take the picture.

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bobg

31

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

« Reply #168 on: 28 / September / 2009, 21:02:51 »

Did you ever find a solution to getting longer exposures? I'm having the same problem with an SD1100.

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zerox

4

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

« Reply #169 on: 05 / November / 2009, 16:27:27 »

Hi. I have a question. Is it possible to implement long exposure function in SX100IS version of CHDK?
If so, then can anybody try do this?

Thanks!

Edit.
Or maybe this is hardware limitation?

« Last Edit: 06 / November / 2009, 05:28:23 by zerox »

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