beginner astrophotography

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    beginner astrophotography
    « on: 01 / October / 2012, 12:05:47 »
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    I have a G12 with firmware 1.00g.  I have successfully loaded CHDK on to my 16GB SD card using ACID.

    I plan to use CHDK for some night photography (star-trails to start).  Is there a relatively easy way to set CHDK so when I start CHDK it has the following settings:

    ISO 800
    F-STOP 2.8
    Manual focus – Infinity
    Noise reduction – OFF
    Image review – OFF
    30 Second Exposure
    Dark Frame subtraction - off

    I would prefer to change config files (or whatever) on my PC.  I find it difficult to navigate the CHDK menus on the camera.  Perhaps I will be more comfortable with this later.

    I am very new to manual photography and CHDK.  Any additional input is welcome!

    Thanks!
    G12

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    Offline lapser

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    Re: beginner astrophotography
    « Reply #1 on: 01 / October / 2012, 12:54:47 »
    You can do everything with just the camera except turning off dark frames. Go to the CHDK main menu and scroll down to "RAW". Then scroll down again to "Dark Frame..." and set it to OFF. Don't turn on RAW file saving. Better to learn  more about the camera first.

    The best way to do star trails is with a time lapse script. It's worth learning to run scripts. You press the SET button to get to the script menu. Load a script file, then press the shutter button all the way down to start it, and again to stop the script. You can probably use a simple script that just calls "shoot" repeatedly as fast as possible, so you don't have gaps in the star trails.

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    Re: beginner astrophotography
    « Reply #2 on: 01 / October / 2012, 13:22:25 »
    Thanks!

    I thought there was a 15 second exposure limit, though...?

    I also thought it would be nice for easy setup.  Just run CHDK and my camera is ready!
    G12

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    Offline lapser

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    Re: beginner astrophotography
    « Reply #3 on: 01 / October / 2012, 20:23:46 »
    I thought there was a 15 second exposure limit, though...?
    If the limit is 15 seconds on that camera, you'll need to overrride it with the CHDK menus. It's not hard.
    I also thought it would be nice for easy setup.  Just run CHDK and my camera is ready!
    Most CHDK menu items have the option to reload them at startup, so you only have to figure it out once and it will load the next time.

    The words "CHDK" and "Easy Setup" aren't often used in the same sentence, though. I assure you it's worth the effort to learn. Here's a couple of videos I made using the time lapse script I'm writing.

    http://www.youtube.com/watch?v=zkLBPlY6DRE#ws

    http://www.youtube.com/watch?v=Nr-Q5aztka4#ws


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    Re: beginner astrophotography
    « Reply #4 on: 01 / October / 2012, 20:52:03 »
    I also thought it would be nice for easy setup.  Just run CHDK and my camera is ready!
    You have that right.  That can be very convenient and nice.

    You can write a CHDK script that runs at startup and sets things up for you - either directly or by setting CHDK menu items.  You can also cause CHDK to appear to press camera buttons to set Canon menu items.

    Its going to need to be customized to your needs so you either need to learn CHDK scripting or post what you want to do here (in detail !)  and hope somebody will write a script for you.



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    Re: beginner astrophotography
    « Reply #5 on: 02 / October / 2012, 04:24:20 »
    Photo-star trails

    2 options.
    1) single exposure around 30 mins. f2.8, high iso. You can try iso 800 to 1k but it will be noisy.
    2) Use lapse.lua / ultra-intervalometer script, f2.8, iso 800, 15-20s with 1-2s interval.  Then use a program like startrails.exe to stack all the photos you have recorded so you can see the trails. It will be less nosier at 15s-20s. Set focus to infinity, manual WB(cooler wb will give less noise).

    timelapse stars video.
    Just like option 2 but this time you will use windows movie maker. 


    I have a G12 with firmware 1.00g.  I have successfully loaded CHDK on to my 16GB SD card using ACID.

    I plan to use CHDK for some night photography (star-trails to start).  Is there a relatively easy way to set CHDK so when I start CHDK it has the following settings:

    ISO 800
    F-STOP 2.8
    Manual focus – Infinity
    Noise reduction – OFF
    Image review – OFF
    30 Second Exposure
    Dark Frame subtraction - off

    I would prefer to change config files (or whatever) on my PC.  I find it difficult to navigate the CHDK menus on the camera.  Perhaps I will be more comfortable with this later.

    I am very new to manual photography and CHDK.  Any additional input is welcome!

    Thanks!

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    Re: beginner astrophotography
    « Reply #6 on: 02 / October / 2012, 04:40:02 »
    @lapser, those are beautiful sunsets. What script did you use?

    I thought there was a 15 second exposure limit, though...?
    If the limit is 15 seconds on that camera, you'll need to overrride it with the CHDK menus. It's not hard.
    I also thought it would be nice for easy setup.  Just run CHDK and my camera is ready!
    Most CHDK menu items have the option to reload them at startup, so you only have to figure it out once and it will load the next time.

    The words "CHDK" and "Easy Setup" aren't often used in the same sentence, though. I assure you it's worth the effort to learn. Here's a couple of videos I made using the time lapse script I'm writing.

    http://www.youtube.com/watch?v=zkLBPlY6DRE#ws

    http://www.youtube.com/watch?v=Nr-Q5aztka4#ws

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    Offline blackhole

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    Re: beginner astrophotography
    « Reply #7 on: 02 / October / 2012, 10:10:06 »
    Quote
    1) single exposure around 30 mins. f2.8, high iso. You can try iso 800 to 1k but it will be noisy.

    Exposure of 30 minutes would do completely unusable images in the smallest iso, especially at ISO 800
    Here's the image with the following settings:
    TV 512 sec.
    ISO 65
    f2.8
    F23.2 (EFL 140mm)
    Manual subtracted dark frame, the lighting pollution and ultimately set the histogram in B channel.

    Take a few pictures with similar settings and uses BlackFrame NR to subtract dark frame,then uses startrails.exe and uses a lower resolution (1600x1200).
    To remove the LP could use PixInsight, but making LP mask is quite complicated.
    http://www.mediachance.com/digicam/blackframe.htm
    http://startrails.de/html/software.html
    http://pixinsight.com/

    You can try to catch Iridium flare, it thrives with compact cameras.


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    Offline lapser

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    Re: beginner astrophotography
    « Reply #8 on: 02 / October / 2012, 16:38:41 »
    @lapser, those are beautiful sunsets. What script did you use?
    Thanks. It's a script I'm developing. I'll post it in a few weeks when I work out a few more bugs.

    http://www.mediachance.com/digicam/blackframe.htm
    http://startrails.de/html/software.html
    http://pixinsight.com/
    Thanks for the links. Im my last test, the Canon G1X, with the larger, low light sensor, had NO hot pixels at 60 second 100ISO (cool weather). The SX260 was full of hot pixels with the same settings.

    I love the star trail and the iridium flare. I've captured a lot of satellites going by, but never a flare like that (it comes from a reflection off a solar panel or something on the satellite as it rotates).

    This is a night time lapse I took with a Panasonic FZ150 before I discovered CHDK. Let me know if you think I identified the airplanes, satellites and meteors correctly:

    http://www.youtube.com/watch?v=hoasBykH6-E#ws

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    Offline blackhole

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    Re: beginner astrophotography
    « Reply #9 on: 02 / October / 2012, 17:51:45 »
    Well you do it, the plane is easily recognized by intermittent light (1.13 and 1.22).
    This is probably the best place for identifying and predicting satellites and Iridium flare, but be sure you enter your exact coordinates, Google Earth can help you there, used to display decimal degrees (Tools> Options> 3D View> Show Lat / Long> Decimal degrees) .http://heavens-above.com/ManualLocationInput.aspx?lat=0&lng=0&loc=Unspecified&alt=0&tz=CET
    For Iridium flare you can use the settings:
    P mode
    TV 20 sec
    ISO 100
    shoot 5 seconds before the scheduled time for the appearance of flare.

     

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