GF1: White Balance for Light Sticks?

Discussion in 'Panasonic Cameras' started by ctawn, Jun 4, 2010.

  1. ctawn

    ctawn New to Mu-43

    6
    Jun 4, 2010
    I tried to take some shots that included light sticks at an amusement park. Plenty of ambient colored lights in trees. So I set GF1 to shutter speed priority mode (30). Everything turned out as expected except the colored light sticks, which were almost entirely white. Playing with white balance settings didn't seem to matter. Is this some kind of limitation of florescent lighting? They looked normal in the digital view finder...
     
  2. f6cvalkyrie

    f6cvalkyrie Mu-43 All-Pro

    Feb 12, 2010
    Brussels, Belgium
    Hi,

    without seeing an example picture, I can only take an educated guess : the fluorescent tubes are overexposed. This is very often the case when you expose dark (evening) scenes with visible light sources. They are too strong compared to the rest of the scene. You could expose for the light sources, but then the rest of the scene turns too dark. The dynamic range of the scene is just too big to be registered correctly.

    One way around it : HDR with a shot for the highlights and a shot for the shadows.

    I hope this helps :smile:

    C U,
    Rafael
     
  3. photoSmart42

    photoSmart42 Mu-43 Top Veteran

    628
    Feb 12, 2010
    San Diego, CA
    Were you using AWB (auto white balance), or custom WB? AWB is limited in its interpretation of what is white, so it's best for situations with complex lighting to do a custom WB using a gray card. It could also be an issue of overblown highlights caused by the intensity of the light stick if they were really bright compared to the rest of the background.

    Sometimes these things happen because we're dealing with software algorithms that are a software programmer's interpretation of how the sensor should interpret the world it sees.
     
  4. ctawn

    ctawn New to Mu-43

    6
    Jun 4, 2010
    exactly, the educated guess is correct -- the light sticks were over-exposed. it was on AWB but I adjusted it up and down with the dial to no effect. no idea what HDR is... and it seems like you're saying even with a grey card there's no way to get both the color of the light sticks and the background. but what puzzles me is why does the preview look just fine?
     
  5. photoSmart42

    photoSmart42 Mu-43 Top Veteran

    628
    Feb 12, 2010
    San Diego, CA
    I think the software for the preview in the EVF/LCD errs on the side of brighter lights (it's also a function of how you've set up your metering), so while you saw the glow-stick more clearly in the EVF/LCD, what you probably didn't notice was the loss of detail in the shadows.

    If you want to capture the glow-stick specifically, you might have to do a spot meter on it, then do an AE lock to lock in that exposure before you move your camera to compose the scene the way you want. You'll lose detail in the shadows, but that's the compromise of having a limited dynamic range.
     
  6. f6cvalkyrie

    f6cvalkyrie Mu-43 All-Pro

    Feb 12, 2010
    Brussels, Belgium
  7. ctawn

    ctawn New to Mu-43

    6
    Jun 4, 2010
    I see... thanks, I'll study that. Any specific ways to implement that on the GF1 that you can recommend?

    (I see for sure I'll need to use RAW mode. Seems like a tripod would also be essential.)
     
  8. f6cvalkyrie

    f6cvalkyrie Mu-43 All-Pro

    Feb 12, 2010
    Brussels, Belgium
    Sorry, ctawn, I don't own a GF1 but a G1.
    In general, you can do it with one or more RAW - files.

    If you should just one RAW, then develop it 3 times, at - 2 stops, normal and +2 stops. Merge these 3 pics and adjust parameters of merging for your liking.

    If possible (camera on tripod and no moving objects in the frame), try shooting 3 pics (minimum), at -2/0/+2, develop them normally and merge.

    Be aware that on many forums, participants can react rather hostile on "overcooked" HDR images. Have not seen any such reactions here, but you never know :biggrin:

    Have fun, the serious work is just starting.
    After HDR, there is still "focus stacking" left ... and many other techniques :eek:

    Rafael
     
  9. f6cvalkyrie

    f6cvalkyrie Mu-43 All-Pro

    Feb 12, 2010
    Brussels, Belgium
  10. JoepLX3

    JoepLX3 Mu-43 Top Veteran

    509
    Jun 13, 2010
    Japan
    Personally I like it for a limitted amount of picture within a collection and only if you keep some kind of "natural" look, that is as if you could have made it in darkroom, but then inside your PC :rofl:.