Page 1 of 2 12 LastLast
Results 1 to 10 of 12

Thread: difficuly recording beam shows

  1. #1

    Default difficuly recording beam shows

    Hi dudes.

    i saw some cool LEM videos and decided to record some videos of my own beam animations. I started the projector and tried recording with iphone 4s, my lumia phone, a 2007 year sony camcorder and i keep getting cutting artifacts.

    i tried different iso and shutter speed settings but the problem doesnt go away.
    Last edited by zorn; 04-28-2016 at 15:50.

  2. #2
    Join Date
    Jan 2013
    Location
    Detroit, USA
    Posts
    558

    Default

    In that first pic it looks like the lasers are made of ribbons, which is pretty cool.

  3. #3
    Join Date
    Aug 2008
    Location
    UK
    Posts
    5,675

    Default

    Rolling Shutter.

    Look at my Avatar and you'll see a similar effect albeit at the shutter speed I took it at, there weren't gaps presumably as it recorded more than 1 scan.

    I believe Andy Con on here is quite good a laser photography. Might be worth giving him a shout for shutter speed advice.

  4. #4
    Join Date
    Dec 2012
    Location
    Norway, Stavanger
    Posts
    69

    Default

    Banding and, rolling shutter and ribbons can occure at certain scanspeed and Fps&shutterspeed combos, Try and record at 24 Fps with 1/24 shutterspeed or 30Fps with 1/30th shutterspeed, If it gets dark try and bump the iso or open the aparature abit. Its a bit challenge at first but you get a feel of what scanspeeds do what at those combos. Try and get the camera to have as low fps/shutter combo but aproxamently as close as the eye (around 24Fps) having a low Fps with a high shutter will produce those ribbons in and cuts like you have in your pictures.

    That is if you have a DSLR to record with. But some people have gotten very good results with iphone cameras , Would recommend DSLR's for higher quality and more fine control over everything.

    -Hybrid
    Last edited by hybridz0rz; 05-12-2014 at 14:04. Reason: Adding info
    1x - 2W RGB DT40Pro (Currently building)
    1x - 1W RGB PT25K
    ------------------------------------
    EtherDream, LaserShowExpress, Ipad (TouchOSC)
    -Hybridz0rz

  5. #5

    Default

    video is a hard one with lasers, it really comes down to each recording device. they are all different.

    photos are easy

    I would rule phones out straight away, DSLR cameras are the way to go. you will just need to have a play with the settings and see what works for your camera.
    Eat Sleep Lase Repeat


    Aluminium Optic Mounts

    http://www.laser-man.co.uk/opticmounts/

  6. #6
    Join Date
    Dec 2012
    Location
    Norway, Stavanger
    Posts
    69

    Default

    I use DSLR's and some times the video just works. but other times it just doesn't, as i said earlier and aswell as Andy_Con said. DSLRs is the best option and would give you full controll over everything, (Especially with Canon Dslrs with the MagicLantern hack).

    Examples:
    This shows more or less true to the eye reproduction, what flickers on video flickers in real life:
    https://www.youtube.com/watch?v=n1oEhbUy2RY

    This video has messed up settings and is not showing true to the eye video: (to high of a shutter was used)
    https://www.youtube.com/watch?v=CKxBWqITz9I

    -Hybrid
    1x - 2W RGB DT40Pro (Currently building)
    1x - 1W RGB PT25K
    ------------------------------------
    EtherDream, LaserShowExpress, Ipad (TouchOSC)
    -Hybridz0rz

  7. #7
    Join Date
    Aug 2008
    Location
    UK
    Posts
    5,675

    Default

    Quote Originally Posted by zorn View Post
    What about the suggestion i was given that it is caused by the camera 'matrix' and i should use a video camera (camcorder) instead of a regular camera with video recording capability? should i waste my time trying to find a video camera which i havent been able to yet or is it a wrong guess and i shouldnt waste my time on that? Maybe by this suggestion they meant not to use a DSLR camera?
    Rolling shutter is caused by CMOS sensors which are without global shutters, irrespective of the type of device they're used in.

    CCD devices generally use global shutters.

    So unless you can find a device with a CCD and thus global shutter (quite rare these days as CMOS are cheaper), then you're going to have the problem of trying to minimise the effect through camera settings. Generally CCD's are found in high end video equipment. Most consumer stuff uses CMOS just the same as most stills cameras.

    DSLR's generally give you very good control over settings as do professional level video cameras. Anything that automatically controls one or more aspects is best avoided.
    Last edited by White-Light; 05-12-2014 at 14:48.

  8. #8
    Join Date
    Feb 2008
    Location
    East Sussex, England
    Posts
    5,127

    Default

    Try bumping your scan speed 1000 pps up or down and see how it shifts the problem.
    http://www.facebook.com/SubsonicSystems
    http://www.frikkinlazors.co.uk

    You are using Bonetti's defense against me, ah?

    I thought it fitting, considering the rocky terrain.

  9. #9
    Join Date
    Feb 2008
    Location
    East Sussex, England
    Posts
    5,127

    Default

    I'm suggesting that you try it. Your camera 'sees' stuff differently to your eyes, so a flicker you can see may not necessarilly show up on the camera footage.
    http://www.facebook.com/SubsonicSystems
    http://www.frikkinlazors.co.uk

    You are using Bonetti's defense against me, ah?

    I thought it fitting, considering the rocky terrain.

  10. #10
    Join Date
    Dec 2012
    Location
    Norway, Stavanger
    Posts
    69

    Default

    Quote Originally Posted by zorn View Post
    Hey dudes so I tried all the suggestions today and i cant get rid of the "rolling shutter" artifact...

    if recording as a 1920x1080 video, the fps is fixed at 25 fps, but the shutter speed cant be set lower than 30.
    i changed the video resolution to 1280x720 and in that case the fps is set to 50, but then i cant set the shutter speed to lower than 60.
    Might this be the problem? because im not able to manually set the fps and shutter speed the same number, or is that normal and i should think of something else?...
    You cant have a shutter speed slower then the FPS, because then it would get out of sync and overlap. You should be able to have close to or the same shutterspeed as you FPS. Some canon cameras needs to have the Magic lantern hack to manualy lower the Shutter to the same FPS.

    Try changing the PPS, FPS and Shutter untill you get a good combo that works for you.

    -Hybrid
    1x - 2W RGB DT40Pro (Currently building)
    1x - 1W RGB PT25K
    ------------------------------------
    EtherDream, LaserShowExpress, Ipad (TouchOSC)
    -Hybridz0rz

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •