Long-Exposure Continuous Shooting (for star trails or other uses)

reyalp

14118

Re: Long-Exposure Continuous Shooting (for star trails or other uses)

« Reply #20 on: 22 / July / 2013, 22:26:31 »

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Quote from: waterwingz on 22 / July / 2013, 22:16:30

Seems like the half_shoot is where the camera decides on the exposure and focus settings, so you'd want to insert the overrides after that?

The CHDK override hook gets called during half shoot, so script needs to set beforehand. The script call just sets a variable the override hook will read later.

If you want to manipulate things inside half_shoot, you can do it by setting propcases directly, though I'm not sure how reliable or sensitive to timing this method is.

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waterwingz

12140

Re: Long-Exposure Continuous Shooting (for star trails or other uses)

« Reply #21 on: 22 / July / 2013, 22:54:52 »

Quote from: reyalp on 22 / July / 2013, 22:26:31

The CHDK override hook gets called during half shoot, so script needs to set beforehand. The script call just sets a variable the override hook will read later.

So the correct way to think about this is that you set overrides before the half-shoot determines exposure and they will replace what half-shoot came up with.

Where does set_aflock() fit into this process ?

I'm thinking a wiki page is in order here ... I usually get it to work right with each new script but I feel like I always end up "re-inventing the wheel".

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Ported : A1200 SD940 G10 Powershot N G16

reyalp

14118

Re: Long-Exposure Continuous Shooting (for star trails or other uses)

« Reply #22 on: 23 / July / 2013, 00:00:30 »

Quote from: waterwingz on 22 / July / 2013, 22:54:52

So the correct way to think about this is that you set overrides before the half-shoot determines exposure and they will replace what half-shoot came up with.

Right. Which is actually undesirable if you want to base your exposure on the measured Bv, since it only updates in half shoot. We've discussed this somewhere before.... http://chdk.setepontos.com/index.php?topic=9110.msg94450#msg94450

Hmm, I thought you were involved too, maybe a different thread.

Quote

Where does set_aflock() fit into this process ?

Beats me, haven't played with that one much. But set_aflock() calls the Canon function directly rather than setting a flag for the override hook.

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waterwingz

12140

Re: Long-Exposure Continuous Shooting (for star trails or other uses)

« Reply #23 on: 23 / July / 2013, 00:28:08 »

Quote from: reyalp on 23 / July / 2013, 00:00:30

Right. Which is actually undesirable if you want to base your exposure on the measured Bv, since it only updates in half shoot.

That's why some of my script do a half-press and release just to get the current Bv prior to actually doing a shoot().

Quote

Quote
Where does set_aflock() fit into this process ?
Beats me, haven't played with that one much. But set_aflock() calls the Canon function directly rather than setting a flag for the override hook.

Seems like philmoz tried to shed some light on the correct placement a couple of months ago. I'll go back and look for it.

Update : in case I end up back here, the post was : http://chdk.setepontos.com/index.php?topic=9533.msg97810#msg97810

« Last Edit: 29 / July / 2013, 09:34:09 by waterwingz »

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Ported : A1200 SD940 G10 Powershot N G16

Intheswamp

16

Re: Long-Exposure Continuous Shooting (for star trails or other uses)

« Reply #24 on: 23 / July / 2013, 09:22:13 »

Just so you don't think I'm a hit-and-run user I want to let ya'll know that I'm still here...ya'll pretty well lost me on page two but I'm still here.

Ed

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waterwingz

12140

Re: Long-Exposure Continuous Shooting (for star trails or other uses)

« Reply #25 on: 23 / July / 2013, 09:28:04 »

Quote from: Intheswamp on 23 / July / 2013, 09:22:13

Just so you don't think I'm a hit-and-run user I want to let ya'll know that I'm still here...ya'll pretty well lost me on page two but I'm still here.

Thanks. Here's the latest version - seems to work more stably than the rest although the first time it runs it still does not always use long exposures.

Give it a try and see what it does for you?

lecshoot.lua (1.07 kB - downloaded 76 times.)

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Ported : A1200 SD940 G10 Powershot N G16

Intheswamp

16

Re: Long-Exposure Continuous Shooting (for star trails or other uses)

« Reply #26 on: 23 / July / 2013, 13:09:03 »

I will check it out this evening. I've got the A1200 perched in a downtown window taking a time lapse series. I set up a weather station website a couple of months ago and have started uploading a time lapse of weather every few days...cloud movement is very interesting. I'm still figuring out the best settings for the movies. If your curious about them the videos are at http://www.beeweather.com/wxtlapse001.php . The name of the website incorporates another hobby of mine...honey bees. I've still got to get a greater presence of the bees on the website, though. CHDK has been a treat for me!

Ed

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waterwingz

12140

Re: Long-Exposure Continuous Shooting (for star trails or other uses)

« Reply #27 on: 23 / July / 2013, 14:13:15 »

Quote from: Intheswamp on 23 / July / 2013, 13:09:03

If your curious about them the videos are at http://www.beeweather.com/wxtlapse001.php .

Nice - you certainly get some interesting weather this time of year down there in L.A.

Roll tide.

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Ported : A1200 SD940 G10 Powershot N G16

Intheswamp

16

Re: Long-Exposure Continuous Shooting (for star trails or other uses)

« Reply #28 on: 23 / July / 2013, 19:55:30 »

Thanks Waterwingz. Yelp, we are having a very odd summer down here. It should be busting 100F and DRY right now...we've had more rain this summer than I recall in recent times and the temperature has only gotten up to around 95-96F....it's really been a nice, (mostly) comfortable summer...if you can ignore the humidity!

For anybody that has ever driven highway 331 to the beaches down at Destin/Ft.Walton then you very well may have driven down the street shown in some of the timelapses...it is downtown Luverne, Alabama.

Yo!!!....ROLL TIDE!!!!!!!!! Dang that felt good to this redneck!

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Intheswamp

16

Re: Long-Exposure Continuous Shooting (for star trails or other uses)

« Reply #29 on: 27 / July / 2013, 15:50:50 »

Well, I finally made it back an lecshoot.lua seems to be working good. I've still gotta memorize all the key presses on the A1200 so I can turn the lcd off and then start lecshoot.lua. It's coming together and a far cry better than before I found CHDK!!!!

THANKS!!
Ed

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