Best CHDK tips for the Orionid meteor shower this Sunday ?

  • 68 Replies
  • 9677 Views
  • Publish
    Re: Best CHDK tips for the Orionid meteor shower this Sunday ?
    « Reply #20 on: 20 / October / 2012, 17:57:31 »
    Advertisements
    Which script would you recommend for that? I was hoping to see some meters last night to do some testing, but that didn't happen, so now I'm on a time crunch.  :(  Most of the scripts I've seen adjust time between shots, but I've not seen anything about adjusting exposure times (or perhaps I don't know what I'm looking for.)
    Well,  the one I posted above is all I have to offer.

    Quote
    [EDIT] What's the point of taking dark frame pics? Does that help in Photoshop?[
    If you take a picture with an exposure time longer than about 1 second,  your camera will automatically take a second picture of the same length with the shutter closed and then subtract that picture from the first one.  This removes some of the thermal noise ( called "amp glow") that builds up during longer exposures.    Obviously, this means that if you are taking 30 second exposures of star trails,  the camera will spend 50% of its time taking the "dark frame" image and you will miss 1/2 of what goes by in the night sky.  If you take a dark frame picture separately and use it to post-process your image,  you can tell CHDK to turn of the built-in dark frame process of your camera.
     

  • Publish
    Re: Best CHDK tips for the Orionid meteor shower this Sunday ?
    « Reply #21 on: 20 / October / 2012, 18:29:33 »
    I'm getting an "ukn stmt" which I presume means unknown statement, probably related to the "native call" feature you wrote about. Is this script not compatible with the firmware and/or model of my camera?  :(

    Canon 300 ELPH Powershot

  • Publish
    Re: Best CHDK tips for the Orionid meteor shower this Sunday ?
    « Reply #22 on: 20 / October / 2012, 18:36:02 »
    I'm getting an "ukn stmt" which I presume means unknown statement, probably related to the "native call" feature you wrote about. Is this script not compatible with the firmware and/or model of my camera?  :(

    Canon 300 ELPH Powershot
    It needs to have Lua native mode enabled.    Use the version from CHDK-DE (link posted above) and run the default script on startup to switch it to work in English.

    *

    Offline reyalp

    • ******
    • 9881
  • Publish
    Re: Best CHDK tips for the Orionid meteor shower this Sunday ?
    « Reply #23 on: 20 / October / 2012, 18:49:59 »
    I'm getting an "ukn stmt" which I presume means unknown statement, probably related to the "native call" feature you wrote about. Is this script not compatible with the firmware and/or model of my camera?  :(

    Canon 300 ELPH Powershot
    unk stmt is a ubasic error. To run a lua script, the file extension must be .lua
    Don't forget what the H stands for.


  • Publish
    Re: Best CHDK tips for the Orionid meteor shower this Sunday ?
    « Reply #24 on: 20 / October / 2012, 18:53:46 »
    unk stmt is a ubasic error. To run a lua script, the file extension must be .lua
    Good catch - I thought that looked strange.   He needs a version with native calls enabled as well though.

    *

    Offline lapser

    • *****
    • 1022
    • SX50_100b / SX260_101a / G1X_100g / D20_100b
  • Publish
    Re: Best CHDK tips for the Orionid meteor shower this Sunday ?
    « Reply #25 on: 20 / October / 2012, 18:57:46 »
    Code: (lua) [Select]
    --[[
    @title MLapser
    @param d Shots per Dark Frame
    @default d 50
    --]]

    -- close mechanical shutter
    function  closeshutter()
      if (call_event_proc(closeproc) == -1) then
        print("closeshutter failed")
      end
    end

    -- open mechanical shutter
    function openshutter()
      if (call_event_proc(openproc) == -1) then
        print("openshutter failed")
      end
    end

    --print_screen(1)
    if (type(call_event_proc) ~= "function" ) then
      error("your CHDK does not support native calls")
    end
    bi=get_buildinfo()
    if bi.os=="vxworks" then
      closeproc="CloseMShutter"
      openproc="OpenMShutter"
      if (call_event_proc("InitializeAdjustmentFunction") == -1) then
        error("InitAdjFunc failed")
      end
    elseif bi.os=="dryos" then
      closeproc="CloseMechaShutter"
      openproc="OpenMechaShutter"
      if (call_event_proc("Mecha.Create") == -1) then
        error("Mecha.Create failed")
      end
    else
      error("Unknown OS:" .. bi.os)
    end

    npic=0
    press("shoot_half")
    while(not get_shooting())do sleep(100) end

    repeat
      dark=(npic%d==0)
      npic=npic+1
      print(npic,dark)
      if(dark)then
        closeshutter()
      end
      ecnt=get_exp_count()
      press("shoot_full_only")
      repeat
        sleep(20)
      until(get_exp_count()~=ecnt)
      release("shoot_full_only")
      if(dark)then
        openshutter()
      end
      sleep(10)
    until false
    Here's my script for shooting the meteor shower, with automatic dark frames, derived from the fudgey script. I used the native call compiled version that blackhole provided (thanks again!)

    The G1X has full manual control, but you can also set up any camera with the CHDK Enhanced Photo Operations from the main menu. You need to set ISO, shutter speed, aperture (widest for night shots), and focus. If you don't, the script uses the automatic values from the first picture. That may or may not work the way you want. It's best to take some test pictures until you see what you want, and then use those values. I'm thinking of trying 60 second shutter speed and ISO 100 to start, and adjust from there. Also, be sure to turn off dark frames in the RAW menu. The G1X has native RAW, so I don't need to use the CHDK version raw, except to turn off auto dark frames.

    I used the "shoot_full_only" button for each shot, which holds exposure and focus between shots. It also saves about 1 second of the delay between shots since it doesn't measure the brightness each time. get_shooting() is always true this way, so the only way I could figure out how to tell when the picture is done was to wait for the exposure count to change. It seems to work.

    Code: (lua) [Select]
    --[[
    @title ShLapser
    --]]
    press("shoot_half")
    while(not get_shooting())do sleep(100) end
    repeat
      ecnt=get_exp_count()
      press("shoot_full_only")
      repeat
        sleep(20)
      until(get_exp_count()~=ecnt)
      release("shoot_full_only")
      sleep(10)
    until false
    If you just want to shoot as fast as possible so you won't miss any meteors, without worrying about automatic dark frames, or native calls, try the above script. You can shoot a dark frame at the beginning and end manually, with the lens cap on or lens covered somehow.
    « Last Edit: 20 / October / 2012, 18:59:59 by lapser »

  • Publish
    Re: Best CHDK tips for the Orionid meteor shower this Sunday ?
    « Reply #26 on: 20 / October / 2012, 19:29:55 »
    I have a few more checks in my script at startup - making sure the camera is in P mode and the flash is off.  It also switches to shooting mode automatically if you accidentally start the script in playback mode.

    My next step is to add a bit of code to start & stop shooting based on time of day.  I really don't want to get up at 2 AM to start the camera or return at 6 AM when then sun comes up.

    So I added the checks listed above because I won't be there at 3 AM to notice that I forgot to disable the flash.


    *

    Offline lapser

    • *****
    • 1022
    • SX50_100b / SX260_101a / G1X_100g / D20_100b
  • Publish
    Re: Best CHDK tips for the Orionid meteor shower this Sunday ?
    « Reply #27 on: 20 / October / 2012, 20:07:26 »
    I have a few more checks in my script at startup - making sure the camera is in P mode and the flash is off.  It also switches to shooting mode automatically if you accidentally start the script in playback mode.

    My next step is to add a bit of code to start & stop shooting based on time of day.  I really don't want to get up at 2 AM to start the camera or return at 6 AM when then sun comes up.

    So I added the checks listed above because I won't be there at 3 AM to notice that I forgot to disable the flash.
    Good ideas. There are a million ways to mess up a time lapse, and I've done most of them. I think I'll put a check list into my phone or something.

    Weren't we talking about using an 8.4 volt external battery for the 7.4 volt G1X? I discovered that the "full" voltage for the G1X is 8.2 volts, so I got the 8.4V external battery and a 7.4 volt AC to DC power supply with a dummy Canon G1X battery. It works well, and shows a constant 50% full or so. I don't have the connector for the 8.4V yet, but it should work fine.

    Do you have an external supply? I suppose a wide angle lens attachment would help too.


  • Publish
    Re: Best CHDK tips for the Orionid meteor shower this Sunday ?
    « Reply #28 on: 20 / October / 2012, 22:08:36 »
    Do you have an external supply? I suppose a wide angle lens attachment would help too.
    I have elcheapo Chinese power supplies for all three of my Canon P&S cams.   So far none of them have overheated or caused trouble on 8+ hr shooting runs.

    I've been looking for a high efficiency DC-DC converter that will let me take a 12V car battery as the input and adjust the output as necessary for each of my cams.  Should be able to run for days from something like that.  And motorcycle / RV batteries can be had that are a lot smaller if necessary.



    « Last Edit: 20 / October / 2012, 22:10:23 by waterwingz »

  • Publish
    Re: Best CHDK tips for the Orionid meteor shower this Sunday ?
    « Reply #29 on: 20 / October / 2012, 22:52:25 »
    "Use the version from CHDK-DE (link posted above) and run the default script on startup to switch it to work in English."

    Do I copy over all the files? (CHDK directory, diskboot.bin, and buildconf.txt). I ran the default script, but I'm still getting the same error. (I renamed meteor.bas to metero.lua)

    [EDIT] the only thing in the CHDK direc. was Modules, so I overwrote my old ones with the new ones.)
    « Last Edit: 20 / October / 2012, 22:55:52 by MeBeJedi »

     

    Related Topics