Astrophotography Time Lapce using CHDK - blog post

[guysoft42]

Hi all,

I just wrote on my blog a post about CHDK
I used it during the last meteor shower to try and catch them, and also made animations of moving stars.
Here are the animations

Hope enjoy it
Guy

[RaduP]

Wow, how did you manage to get that much ampglow in some of your videos? What exposure did you use?

[bongo_bingo]

Very interesting!

Thanks fo share

[guysoft42]

Wow, how did you manage to get that much ampglow in some of your videos? What exposure did you use?

If by ampglow you mean the light at the top edge of the frame. Then I have a bad feeling its the chip warming up from long exposure times and the intensity of them. Also there might have been light pollution

[@rt]

Hi, I get a page load error. Anyone else have problems?

[RaduP]

If by ampglow you mean the light at the top edge of the frame. Then I have a bad feeling its the chip warming up from long exposure times and the intensity of them. Also there might have been light pollution

Yes, but the ampglow should only happen with really long exposures, like 2+ minutes or more, so that's why I asked what exposure you used.

[guysoft42]

If by ampglow you mean the light at the top edge of the frame. Then I have a bad feeling its the chip warming up from long exposure times and the intensity of them. Also there might have been light pollution

Yes, but the ampglow should only happen with really long exposures, like 2+ minutes or more, so that's why I asked what exposure you used.

Have no way to explain that.. you can see the code I used.

@rt, Here its fine, and I am getting a lot of traffic. Is it ok now?

[reyalp]

I'd guess you had dark frame subtraction off.

[@rt]

If by ampglow you mean the light at the top edge of the frame. Then I have a bad feeling its the chip warming up from long exposure times and the intensity of them. Also there might have been light pollution

Yes, but the ampglow should only happen with really long exposures, like 2+ minutes or more, so that's why I asked what exposure you used.

Have no way to explain that.. you can see the code I used.

@rt, Here its fine, and I am getting a lot of traffic. Is it ok now?

Still not working for me unfortunately.
I get a page load error using Firefox.

[Hacki]

The link in the first posting is broken. It should be http://guysoft.wordpress.com/about/videos-of-sky/

[zeno]

Chop the "p//" out of the html link and it works (at least it does for me)

[guysoft42]

The link in the first posting is broken. It should be http://guysoft.wordpress.com/about/videos-of-sky/

Ok, that will explain other posts, fixed.

I'd guess you had dark frame subtraction off.

Yes, I am not sure how to do a darkframe. Do you know what settings I should put on the camera to make one? I could add it to the script for next time.

[reyalp]

Yes, I am not sure how to do a darkframe. Do you know what settings I should put on the camera to make one? I could add it to the script for next time.

You can set canon darkframe subtraction auto, off or on using set_nr (0,1,2 respectively). Note that this will take a darkframe after each exposure, doubling the time required to capture each image, and halving your actual coverage of the sky.

You could also take a darkframe manually (by covering the lens) and subtract it in post processing. You'll probably want to work in raw or DNG if you do this.

[guysoft42]

You could also take a darkframe manually (by covering the lens) and subtract it in post processing. You'll probably want to work in raw or DNG if you do this.

Isn't it possible to make a script that will create a darkframe (without using your hands)?

Also, do you have a way to automatically batch process raw .CRW files? I did not find any tool for this.

[reyalp]

You could also take a darkframe manually (by covering the lens) and subtract it in post processing. You'll probably want to work in raw or DNG if you do this.

Isn't it possible to make a script that will create a darkframe (without using your hands)?

Not yet.

Also, do you have a way to automatically batch process raw .CRW files? I did not find any tool for this.

There are some command line tools that understand CHDK CRW.  dcraw for example. You could easily make a shell script/batch file to do bulk processing.