Identical GL2s White Balance Blues

Viewing 7 reply threads
  • Author
    Posts
    • #39343
      Avatarvideojunke
      Member

      I use two GL2s and shoot a lot of theater performances (dance and choral concerts, plays, etc.) and I’m having difficulty getting the white balance on both cameras to match up. I’m usually able to get the light crew to bring up full stage lights and house lights off before the performance and then I zoom in on the cyc. I’ve tried auto and manual white balance and expodisc’s digital white balance filter. The only thing else I can think of is using a white sheet. Any suggestions on how to get both video cameras to balance equally?

    • #170253
      AvatarAnonymous
      Inactive

      junke,

      compusolver has a valid point in regards to the on stage lighting. Question When you tried setting your cameras against a target on stage, were they right next to each other (side by side)?

      I use the same exact cameras and I have found that you can balance them a lot closer if you set them next to one another and shoot a whiteboard under the projected lighting conditions and manually set the balance that way. This way you are shooting under the same exact circumstances. If you have one camera on one side of the stage and the other on the other side and you try to shoot even the same card, the lighting conditions or angles will not be the same thus affecting the color look from each camera. It doesnt take much of a difference to affect the colors. Also keep in mind that you have to make sure that all of the other settings are set identical between both cameras too.

      I’m sure you know this but just in case you don’t, some of the GL2’s settings will revert back to their defaults when the camera is powered down. Make sure you use the stand-by feature so that your settings are preserved.

      Honestly however, Im thinking more like compusolver in that there might be different temp lighting involved on stage. Take it from me when I say that this can play havoc with color on video. I just finished a wedding with huge windows on the sides of this church along with very weak incandescent lighting from up top. What a pain to try and fix in post! The bride had a very white dress in the middle of the church but as I followed her to place some flowers at the statue of Mary (which was closer to a window) her dress started to turn bluish right before my eyes. If the stage is using a certain temp light and then lets say some florescent lighting was added in the mix for whatever reason, youll pretty much have two chances of keeping both cameras looking the same. SLIM & NONE! :'( If this is the case then all you can really do is to try and find a happy median between the two because it is pretty much impossible to prevent this situation from happening with digital video cameras.

      RAM

    • #170254
      Avatarvideobob1
      Participant

      I mostly do dance programs ( Ballet mostly some jazz ) and I had the same problem you did. I now set the white balance to the light bulb setting because the cyc is not a true white and didn’t work well.
      You also have a lot of lighting changes and that plays havoc also.

      Just another note if you don’t already use manual focus TRY IT.
      Zoom in and focus on a dancer downstage, but only a full length shot, because if you go in to far then when you back out to upstage it will be somewhat out of focus.

    • #170255
      AvatarAnonymous
      Inactive

      Hey RAM,

      I just started editing a wedding like that. The stage had nice bright incandescent bulbs, which I set my White balance to. The main portion of the chapel however was lit by fluorescent bulbs along with natural lighting, and if that wasn’t bad enough, the back of the room was lit with some very yellow incandescent bulbs. I watched through my viewfinder as the bride’s dress turned from yellow (at the back) to a bluish green (in the main part of the chapel) to finally white when she got on stage. Now that’s a dress of a different color!

      On topic, the interior light setting on the GL-2 does a fair enough job for most interior lighting, but I’ve noticed that on staged performances, sometimes it’s not perfect. Of course, on the flip side, if you set both cameras to this setting, both will be imperfect in the same manner, which in theory means that it’s easy to adjust all your footage.

      If white balance really matters to me, I bring along a white 18"x36" foam core poster board panel that I’ll set up. If you do that, just keep the board away from glare, and don’t turn off your cameras once the WB is set, but your color will be a little truer than if you just go with the preset.

    • #170256
      AvatarAnonymous
      Inactive

      On a Roll:

      Now that’s a dress of a different color!

      X-D LOL

      Yeah… A white board is the way to go for WB set-up in tough situations but it still won’t solve the changing light conditions during a continous video shot. It’s just the nature of the beast. I guess if someone complained about it all you can do is tell them that there is nothing you can do about it and if they don’t believe you have them ask anybody else who knows what they’re doing and see if they hear the same answer.

      Like I mentioned on some other post, wouldn’t it be nice if you had full control of everything during a wedding job? Think about it, perfect lighting, perfect sound, perfect cam angles. Perfect EVERYTHING! 😯

      Now you have to deal with 3 or 4 different light sources, try and catch the sound without babies crying and car horns beeping, mics cracking, organs drowning out the singer, getting in the way of Aunt Mary, being in the right place at the wrong time and vice-versa, running out of tape while the ceremony is still going on. What a challange!

      Man… are we nuts!!!! πŸ˜›

    • #170257
      AvatarCompressor
      Participant

      On a large stage that isn’t lit to one particular area you will need both cameras as close together as you you can, this is due to light spilling over the same area at different angles. One camera reads one light temperature and the other camera reads a different light temperature. Use a white card or a white piece of paper because this will give you the flattest whitest source you can get. Make sure the light is shining on the card evenly. Whatever you white to the cameras are essentially saying "What ever color there is most of on the screen that is what I am going to call white." When you white it to a cyc chances are they use the gray shadowy area inbetween your white white and everything else. Turning the stage lights on and the house lights off is good, but make sure that you have only the stage lights that have no gels on them. This includes cookies if they are used. You don’t want any shadows or colors hitting your white card. Finally, a little tip that I use is in the broadcast industry they use a spectrometer to measure the colors the camera sees. White is usually set at 90%. The GL2s have an option to adjust your zebra stripe. I changed mine so that I start seeing zebras at 90% so that when I white my camera I iris the camera to the point where I just start seeing zebras. That way I know that the camera will be using as much of the CCDs as it possibly can, Not only that but then you know that both cameras are receiving the same amount of light iris wise.

    • #170258
      Avatarhank-okvideoguy
      Participant

      I changed mine so that I start seeing zebras at 90% so that when I white my camera I iris the camera to the point where I just start seeing zebras.

      This is undoubtedly working fine for the broadcast guy who is used to his technique, but others beware…

      First, 90% refers to the IRE rating, I believe – which most of us have no way of measuring. Secondly, zebras respond to exposure, not color temperature. You can get zebras on any color if exposed to enough light or if your iris is open and your gain is up, etc.

    • #170259
      AvatarCompressor
      Participant

      Yes, 90% does mean IRE, which is a measurement for composite video it is also the same rating that zebra stripes do use. So to correct hank there is a way to measure it, and that’s through your zebra stripes. It’s not by any means an accurate measurement. As in, you can’t get an exact reading of 84.3% but you can get an already predetermined reading, such as the way I have already stated in my previous entry. This helps by first making sure that all of your settings are the same on both cameras (including hard to read settings, such as exposure.) It also helps because if you optimize your exposure it gives you a clearer reading. CCDs are similar to the human eye, in that they can only read what they can see. Again hank is correct, zebra does respond to any color. It’s an exposure tool and I apologize if I wasn’t clear enough on that. When you use it to white balance make sure you are white balancing on white. I never meant to make it sound like zebra stripes were a way to tell you that you had a good white to balance to. It just another tool to use in the art of making good video.

Viewing 7 reply threads
  • You must be logged in to reply to this topic.

Best Products

The best new video tech at CES 2019

Every year, we head to CES to check out the latest innovations in consumer technology and look for the next big thing in video production. CES 2019 was no exception.
homicide-bootstrap