Timelapse with variable shutter speed

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Offline wontolla

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    Re: Timelapse with variable shutter speed
    « Reply #10 on: 22 / April / 2008, 17:08:16 »
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    I can't watch the timelapse!

    the playing bar moves for a fiew seconds but the screen remains black.

    Is it me? I have flash player installed  :'(

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    Offline fbonomi

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    Re: Timelapse with variable shutter speed
    « Reply #11 on: 22 / April / 2008, 17:23:05 »
    you are not missing a lot :-)
    I will now check better.


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    Offline fbonomi

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    Offline wontolla

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    Re: Timelapse with variable shutter speed
    « Reply #13 on: 22 / April / 2008, 17:52:24 »
    Darn!, both show the QuickTime icon with an interrogation symbol.

    Don't worry fbonomi, I bet it's my computer. I just reinstaled it. Let's see if someone else can play it.

    Judging by the graphic your scipt seems to work. I'll try it next time the friking weather gives a truce.


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    Offline fbonomi

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    Re: Timelapse with variable shutter speed
    « Reply #14 on: 22 / April / 2008, 18:06:36 »
    I have changed the encoding...
    Can you please try again?

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    Offline wontolla

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    Re: Timelapse with variable shutter speed
    « Reply #15 on: 22 / April / 2008, 18:16:29 »
    Woha!! I was blind but know I see!

    I think it's the first time I see a time lapse of this kind.

    It still looks a little bit "steppy" <-This word doesn't exist, does it?

    I mean, the steps of the graphic can be noticed in the video. Which variable should I modify? Is it a compromise between "s" and "d"?

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    Offline fbonomi

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    Re: Timelapse with variable shutter speed
    « Reply #16 on: 22 / April / 2008, 18:57:20 »
    no, it's the direct effect of the "slowdown effect".

    i.e. if I wait for 4 deltas before actually changing Tv, this means that in the meanwhile the change has become important...

    I am implementing:
    1) a variable, inertial step
    now the Tv changes of +/- 16.

    graph (1#=4 tv)
    ####
    ####
    ######## +16
    ########
    ############ +16
    ############
    ############
    ############
    ################ +16
    ################
    ################

    it should start changing slowly (1 tv) then become faster (8 tv) then stop slowly...



    graph (1#=4 tv)
    ####
    ##### +4
    ####### +8
    ######### +8
    ########### +8
    ############ +4
    ############# +4
    ############## +4
    ############### +4
    ################ +4
    ################

    the overall effect is similar but less "steppy"

    2) the delay
    If I wait 4 deltas before actually changing Tv, in that 4 frames Tv will be constant and a step will be born.
    On the other hand, I must somehow "delay" the changes or sporadic fluctuations will make the exposure bounce up and down


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    Offline fbonomi

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    Re: Timelapse with variable shutter speed
    « Reply #17 on: 22 / April / 2008, 19:05:35 »
    I think it's the first time I see a time lapse of this kind.

    No, there are a few, but never with expositions going up to 60 seconds....


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    Offline Jucifer

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    Re: Timelapse with variable shutter speed
    « Reply #18 on: 23 / April / 2008, 05:00:23 »
    a bit off topic, but mplayer supports quite a few codecs

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    Offline fbonomi

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    Re: Timelapse with variable shutter speed
    « Reply #19 on: 23 / April / 2008, 07:00:15 »
    I am advancing in research with a few different algorithms.

    The fact is, I realize that light variations are VERY different from situation to situation, and different algorithms or tweaks are needed for different situations!

    So, I asking for some help from all you fellows.

    In order to properly test the script, could you please run this script and sens me the results?

    This script reads bightness information and logs it to pr_screen.txt. Also, it shoots a shot every 10 minutes, just to document what was going on and why the light was changing.

    I would like to have the log result for different situations: clear sky / overcast; around noon / at twilight  etc.

    Artistic considerations do not matter, so just stick the camera to the window and let it run for about a couple of hours and send me the PS_SCREEN.TXT file plus the few shots it takes (it's ok even in S size, they are just to understand what's

    That would help me very much.

    Thanks to all the ones that will feel like helping!

    PS: do not leave the camera pointing straight to the sun!

    Code: [Select]
    @title Brightness log

    rem brightness log
    rem reads brightness information every 10 seconds and logs it to pr_screen.txt
    rem Plus, shoots a photo every 10 minutes
    rem please run with following settings
    rem MODE: AUTO
    rem flash: off
    rem Image size: S (the smallest)

    print_screen 1

    print "Start Brightness Log"

    rem loop counter
    p=0

    :loop

    press "shoot_half"
    sleep 1000
    get_bv96 B
    get_sv96 S
    get_av96 A
    get_tv96 T
    release "shoot_half"
    print p,B,S,A,T

    if (p%60=0) then shoot

    p=p+1

    sleep 9000

    goto "loop"
    « Last Edit: 23 / April / 2008, 07:02:09 by fbonomi »

     

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