Worklights - Light gels?

Discussion in 'Digital Video' started by P-Worm, Apr 19, 2007.

  1. P-Worm macrumors 68020

    P-Worm

    Joined:
    Jul 16, 2002
    Location:
    Salt Lake City, UT
    #1
    I'm looking to shoot some video and I want to really work on getting the lighting the way that I want it. Because I don't have much, I only have access to worklights that you would buy at a place like Home Depot. Should I get gels for these lights so that I can match color temperature with the surroundings better? Where can I get some gels? Are they really expensive?

    I obviously don't know what I'm doing in this area, but I want to learn. Can you point me in the right direction?

    P-Worm
     
  2. Artofilm macrumors 6502a

    Artofilm

    Joined:
    Oct 12, 2005
    #2
    Shop lights are great for lighting a film set.

    You mention you want to use gels, and that you want to match the colour temperature of your surroundings. What are you surroundings you want to match?

    You can get some gels but forcing halogen work lights would require some CTB fulls to correct the colour. (depending on your temperature needed)

    This is a website for light gels. Im am not too sure about pricing, but I do know it would probably be best to buy a roll of the gel you want, you will use them again.

    http://www.lowel.com/gels.html
     
  3. P-Worm thread starter macrumors 68020

    P-Worm

    Joined:
    Jul 16, 2002
    Location:
    Salt Lake City, UT
    #3
    It's not just one particular scene, it's actually for a movie that I'm making with my friends. I want to be able to control the lighting better. For example, if I'm indoors and there's a window, I want to be able to match the indoor lighting to the same temperature. Or I might want some gels to give a distinct look.

    Could you explain what CTB fulls are? I'm afraid I know the software side of video much better than I know how to shoot video myself.

    I went to your link and I find it really confusing. You said that it was better to buy in rolls. Aren't these reusable? Why would I need a lot?

    Thanks for your help.

    P-Worm
     
  4. RedTomato macrumors 68040

    RedTomato

    Joined:
    Mar 4, 2005
    Location:
    .. London ..
    #4
    Gels fade after a while.

    I work with theatre, not film, but generally, after a 2 week run I chuck away all the old gels. That's about 10 x 2 hours + technical rehearsal time. (but not all lamps are on at the same time). Having said that, if we're setting up at a new venue, and there's a lamp with the right gel already in the right place, hey, leave it in, I won't bother cutting a new one.

    Theatre gels are also much more strongly coloured, hence they fade faster, and also the lights are sometimes more high wattage - one production, I was putting 13 000 watts on stage, and maybe 20-40 % of that was absorbed by the gels - (darker gels absorb more).

    Film uses more naturalistic gels for colour balancing.

    If you're just starting out, one of the main things that will help is a heat resistant gauze - drape it over your film lights (aka diy work lights) when indoors - it will diffuse the glare. Big pieces of cardboard will help you to mask where you don't want the light to go. It's useful to have a friend(s) to stand around holding that cardboard - works better then fiddling with a stand.

    Try taping white paper over one side of the cardboard, then you have a choice of a shiny side or matt side. You can then use that reflection as a secondary light source if you want (aka fill light).

    One other semi-pro trick I remember from my limited film work is if you're doing any filming indoors, and there's a window with daylight in your composition, try taping a neutral density gel over the whole window - helps balance intensities and gives you better definition on what the camera sees of the outside environment.

    There are books out there that will help, but some of them are over-technical. The main thing for you at your stage is to work with what you have, make the most of it, and try new things, learn how things work. Try not to obsess with spending an hour trying to get a small lighting detail right - if it doesn't work, move on.

    Hope that help.
     
  5. P-Worm thread starter macrumors 68020

    P-Worm

    Joined:
    Jul 16, 2002
    Location:
    Salt Lake City, UT
    #5
    Thanks a lot Red Tomato. That was very helpful. Are there any other suggestions that from people that are in the same boat I am in budget wise? There must be at least a few independent film makers around here that know a bit about lighting.

    I guess my biggest question is what kind of gels I should buy. It's my understanding that there are some colors that take light and make it a certain temperature. How are these labeled?

    P-Worm
     
  6. killr_b macrumors 6502a

    killr_b

    Joined:
    Oct 21, 2005
    Location:
    Suckerfornia
    #6
    Ah, the old lighting conditions matching. Let me pass on to you and everyone at MacRumors the ancient guerilla technique of "Gel the window." :D :D

    Yes, white balance the camera to your lights pointed at a white surface. Then look at how the sunlight looks in the window. Is it too blue? Is it to orange? This is what you want: http://www.filmtools.com/y.html

    Usually you can find a gel to correct it easily. Then, buy a whole role. ;)

    For a distinctive look, shoot perfectly white balanced footage and correct the color to you liking in post.
     
  7. Artofilm macrumors 6502a

    Artofilm

    Joined:
    Oct 12, 2005
    #7
    Film Gels are labeled by the "CT" name. If the gel is to push the light temp. to a blue colour, it will be "CTB". If the gel is to push the lighting temp. towards yellow/orange, it will be named "CTO". That's how to tell what colour gel you are buying.

    Secondly, you then need to know about how powerful the gel is. The power, is labled by a fraction (1/4, 1/2, full). For example, if you have a tungsten (yellow light) , and use a CTB Full, the gel will shift the yellow fully to blue temperature. 1/4, 1/2, etc. gels will make minor shifts to the colour temperature of your light.

    So in other words, if you want to change your Halogen worklight colour temperature to full blue temperature, use a full CTB. But if you want to only change the temperature, but still have a little bit of warmth to the light, use a 1/4 or 1/2.

    Also, in using gels, the gels will make the light dimmer (by aperature stops). So if you use a CTB full gel, u will notice that you cameras aperature will have to be boosted by 1 full aperature stop.

    Really, it is best to probably buy a couple sheets of every colour and temperature rating. Experiment with them, and learn visually what gels REALLY do for you and what colour gel you use the most. This wil save you money in buying a colour temperature gel you wont use because its maybe too small a change or too much of a change.

    I hope this helped!:D
     
  8. P-Worm thread starter macrumors 68020

    P-Worm

    Joined:
    Jul 16, 2002
    Location:
    Salt Lake City, UT

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