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

fudgey

1705
a570is

« Reply #30 on: 10 / April / 2009, 03:42:19 »

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Quote from: ewavr on 08 / April / 2009, 20:29:33

Quote from: fudgey on 08 / April / 2009, 17:42:42
a570 100e works fine for me already.

With sources from reply #27 or #28?

#28 should be ok, I checked your fixes from my disassembly and they seemed correct.

For a570 100e diffs in #27 and #28 are the same now actually since I edited it after you posted the fixes. For 101a there's one difference (you forgot to list one more fix you made "BL sub_ffebcfbc\n" -> "BL sub_ffd0e5d4\n", about 10 lines from "loc_ffd20fa0:\n" forward.

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ewavr

1057
A710IS

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

« Reply #31 on: 10 / April / 2009, 16:53:33 »

Quote from: esu on 07 / April / 2009, 10:12:07

What should I do to make this work in a S5 IS?

Please test - http://ewavr.nm.ru/chdk/for_test/

2 moderators: I propose to split this topic, because long exposures and modding on a A530 very different things.

edit: also for a550 - the same link.

« Last Edit: 10 / April / 2009, 18:26:46 by ewavr »

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bugmenot

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

« Reply #32 on: 10 / April / 2009, 18:12:44 »

quick question: what is the maximum exposure time now with this new feature?

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ewavr

1057
A710IS

Re: extra long exposures

« Reply #33 on: 10 / April / 2009, 18:25:50 »

Quote from: bugmenot on 10 / April / 2009, 18:12:44

quick question: what is the maximum exposure time now with this new feature?

We must make some experiments to answer this question.
IMO, it limited by battery life time and image quality.

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barret

125
S3 & a550

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

« Reply #34 on: 11 / April / 2009, 05:35:23 »

how can i set those long exposure times? i cannot set it through 'extra photo operations' menu... max. is 64 sec.

thanks ewavr

Quote

Set Shutterspeed enum type = factor
then set "override shutter speed" and "value factor"

update: it works!!! thank you ewavr!!!

on canon a550:
100 sec. works!
300 sec. works!
600 sec. works!
1200 sec. works!!!
although image quality (noise) is quite bad. how can we fight it?

« Last Edit: 11 / April / 2009, 10:41:17 by barret »

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my timelapses on Vimeo my startrails gallery

ewavr

1057
A710IS

Re: extra long exposures

« Reply #35 on: 11 / April / 2009, 06:37:02 »

Quote from: barret on 11 / April / 2009, 05:35:23

although image quality (noise) is quite bad. how can we fight it?

See http://chdk.setepontos.com/index.php/topic,3409.0.html

Quote

**Made an Amp-off circuit to control the CCD voltage during the exposure. This is to avoid the CCD glow at the corners of the image.
**Peltier cooling to reduce hot pixels and slightly increasing the sensitivity.

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barret

125
S3 & a550

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

« Reply #36 on: 11 / April / 2009, 06:39:52 »

Quote

See http://chdk.setepontos.com/index.php/topic,3409.0.html Big Grin

oh, yes, thank you, i've read that before

interesting work, but rather extreme, don't you think?

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my timelapses on Vimeo my startrails gallery

ewavr

1057
A710IS

Re: extra long exposures

« Reply #37 on: 11 / April / 2009, 06:44:01 »

Without hardware modding we can only:
- use dark frame subtraction
- use noise reduction software
- use RAW sum (not average) of shorter exposures

or buy DSLR with big sensor

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fudgey

1705
a570is

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

« Reply #38 on: 11 / April / 2009, 13:40:25 »

I haven't done many test shots, but one 10 minute exposure with ISO80 F/11 (that aperture was to get rid of light, F2.6 got me severe overexposure in moonlight) was actually pretty good after Canon's dark frame removal. There was some noticeable noise in the top left corner where amp glow is the worst, but the photo is completely usable when scaled down a bit.

On the other hand, shots that long taken inside in poor light look very bad.

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gremmy

14

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

« Reply #39 on: 12 / April / 2009, 09:18:01 »

I was just wondering if there's a chance that an extended exposure time for the a590 might be available soon. Thanks to all the developers working on this, it really is great.

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