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fixedint.lua: Astrophotography oriented script for long exposure + timelapse

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Offline reyalp

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One thing I'm wondering about is if I enable dark frames then I'm going to get a bigger gap between exposures, resulting in a less smooth movie for the time lapse, unless what you said about the raw therapee program addresses this.
Right, there are two options:
1) Let the camera create and subtract a dark frame for each shot. This will cause a gap equal to the exposure length between each frame, plus the normal saving time.
2) Shoot with dark frames disabled on the camera, and use a separately created dark frame on the images later.

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And do I need to uncheck the "disable canon dark frame" and check the "make dark frames" in the script options?  I don't think the Canon firmware on this camera has dark frame subtraction as an option. 
By default, the Canon firmware on most of these cameras does a dark frame if the exposure is longer than a few seconds. This is actually described in the Canon manuals, they just call it "processing" without mentioning that it's a dark frame.

The "disable canon dark frame" option prevents this. So if you want one dark frame per shot, turn this option off.

The "make dark frames" option shoots with the shutter closed. Use this if you want to make standalone dark frames, but remember to uncheck the option before you try to shoot another timelapse ;)

You need to enabled "Lua native calls" in the miscellaneous menu for the "make dark frames" option to work. Except for the interval and number shots, all the script settings should be left the same as your real shots. The camera should also be at a similar temperature. Averaging several dark frames may give better results.

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I'm still using your unfixed script - I was sure the 5 second interval was working, but I'll check when I use it again.
I'm pretty sure it couldn't work, but it's not the first time I've been wrong. At ISO 1600, the camera will spend a significant amount of time processing (even without dark frames enabled), so the difference between a 5 sec interval and no interval might not be obvious. If you are shooting 32 sec exposures, shooting as fast as possible may be the best approach anyway, the shot to shot variations probably won't be more than a second most of the time.
Don't forget what the H stands for.

I just download fixedint-1.2.zip but the zip includes rawopint.lua 0.19…
M100 100a, M3 101a, 2*G1x (101a,100e), S110 (103a), SX50 (100c), SX230 (101a), 2*S45,
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Offline reyalp

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I just download fixedint-1.2.zip but the zip includes rawopint.lua 0.19…
Whoops  :-[

Re-uploaded with the correct files. Thanks for letting me know.
Don't forget what the H stands for.

I was just starting to play a little bit with the script. My plan was to run the script overnight.

I think it would be a really good option, to have a protection mode in the script which stops it when the overexposure goes to high (Just simple when it goes over 25%). I’m not sure what happens when on 30s exposure time the sun goes up… yes of course you can calculate the runtime but you never know… 
M100 100a, M3 101a, 2*G1x (101a,100e), S110 (103a), SX50 (100c), SX230 (101a), 2*S45,
Flickr https://www.flickr.com/photos/136329431@N06/albums
YouTube https://www.youtube.com/channel/UCrTH0tHy9OYTVDzWIvXEMlw/videos?shelf_id=0&view=0&sort=dd


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Offline reyalp

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I think it would be a really good option, to have a protection mode in the script which stops it when the overexposure goes to high (Just simple when it goes over 25%).
Currently the script doesn't do anything with exposure or metering. I guess it wouldn't be too hard to add.
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I’m not sure what happens when on 30s exposure time the sun goes up…
I'm no expert, but AFAIK all that happens is your photo is ruined. I'm not aware that too much light can do any actual damage. Direct sun might be a different story.

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yes of course you can calculate the runtime but you never know…
One feature I've been meaning to add is start/stop at a particular clock time.
Don't forget what the H stands for.

Currently the script doesn't do anything with exposure or metering. I guess it wouldn't be too hard to add.

I’m thought about very simple like

Code: [Select]
if get_histo_range(1023,1023) > 25 then
logdesc('shutdown: Overexposure')
log:write()
break
end
Or does this function don’t work on longer exposure times?

One feature I've been meaning to add is start/stop at a particular clock time.


Yes I thought about the same…

But this goes now more complicate for me… I always was thinking how I can handle the time on all my (around 10) cams … not changing them always from summer to winter time and back…
I decided now, to set all my cams to UTC independent where I am…


M100 100a, M3 101a, 2*G1x (101a,100e), S110 (103a), SX50 (100c), SX230 (101a), 2*S45,
Flickr https://www.flickr.com/photos/136329431@N06/albums
YouTube https://www.youtube.com/channel/UCrTH0tHy9OYTVDzWIvXEMlw/videos?shelf_id=0&view=0&sort=dd

Re: fixedint.lua: Astrophotography oriented script for long exposure + timelapse
« Reply #16 on: 24 / September / 2017, 09:11:10 »
If I have understood the script correctly, then you have to create the 'dark frames' separately.
Would not it make sense to create them automatically after 'Number of shots '?
So if you run the cam overnight you have not taken care about 'dark frames' on the end…
M100 100a, M3 101a, 2*G1x (101a,100e), S110 (103a), SX50 (100c), SX230 (101a), 2*S45,
Flickr https://www.flickr.com/photos/136329431@N06/albums
YouTube https://www.youtube.com/channel/UCrTH0tHy9OYTVDzWIvXEMlw/videos?shelf_id=0&view=0&sort=dd

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Offline reyalp

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Re: fixedint.lua: Astrophotography oriented script for long exposure + timelapse
« Reply #17 on: 24 / September / 2017, 14:57:49 »
If I have understood the script correctly, then you have to create the 'dark frames' separately.
Would not it make sense to create them automatically after 'Number of shots '?
So if you run the cam overnight you have not taken care about 'dark frames' on the end…
In my workflow, I just make master darks once for a given combination of settings (tv, iso, zoom) rather than making new ones for each session.

If you really wanted to do it right, you'd match darks to the sensor temperature at the time the light frames were taken. Doing it at the end won't necessarily accomplish that, depending on the conditions.

edit:
Using http://chdk.wikia.com/wiki/Meteor_Intervalometer_with_Dark_Frame_Management you should be able to take darks at the end of the run.
« Last Edit: 24 / September / 2017, 15:00:23 by reyalp »
Don't forget what the H stands for.


Re: fixedint.lua: Astrophotography oriented script for long exposure + timelapse
« Reply #18 on: 25 / September / 2017, 05:47:41 »
If you really wanted to do it right, you'd match darks to the sensor temperature at the time the light frames were taken. Doing it at the end won't necessarily accomplish that, depending on the conditions.

For longer timelapse, the temperature is likely to converge (or remain nearly constant). If you create the darks at the end, then this frame will probably be used for most recordings (except the firsts). But is a pure guess on my part…

M100 100a, M3 101a, 2*G1x (101a,100e), S110 (103a), SX50 (100c), SX230 (101a), 2*S45,
Flickr https://www.flickr.com/photos/136329431@N06/albums
YouTube https://www.youtube.com/channel/UCrTH0tHy9OYTVDzWIvXEMlw/videos?shelf_id=0&view=0&sort=dd

Is there any limitation of maximum exposure time?

I increased the maximum exposure time in the script to 3600s. My EOS M3 crashes. It was not the typical crash where the cam goes immediately off. The camera tells my that an error was detected and switches off. ROMLOG attached.

2000s works fine but EXIF says only 300s
M100 100a, M3 101a, 2*G1x (101a,100e), S110 (103a), SX50 (100c), SX230 (101a), 2*S45,
Flickr https://www.flickr.com/photos/136329431@N06/albums
YouTube https://www.youtube.com/channel/UCrTH0tHy9OYTVDzWIvXEMlw/videos?shelf_id=0&view=0&sort=dd

 

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