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Advice for correcting white background shot with 20mm pancake at f1.8
  • RamboRambo

    Yep, I got caught without a good lighting setup in a studio and shot a clip with GH2 and 20mm pancake at f1.8. The clip is of a white and red machine with an actor onboard. The background is a white wall and the combination of the lens at 1.8 and and uneven lighting resulted in a graduated vignette effect (getting darker further from the centre) I guess the pancake has a fair bit of light falloff at that aperture.

    I've applied a grad exposure from two sides with Magic bullets and a general lift in exposure and Neat video. This results in banding, washout out colours and the white subject parts disappearing into the white background.

    I bounced a very bright tungsten light off the ceiling as that's all that was available in the studio.

    Any ideas please.

  • 12 Replies sorted by
  • GravitateMediaGroupGravitateMediaGroup

    why NLE do you use?

    and can you take a screenshot?

  • RamboRambo

    Vegas pro 12, also have AE but not really proficient in AE.

    Sorry can't show the actual product but I have mostly masked that out of the centre and left the problem area intact as well as a portion of the white subject at the bottom.

    I shot this badly under exposed as well, this is the worst of it not all is like this. Actually most of the shoot is properly exposed but still shows vignette.

    image.jpg
    1280 x 720 - 45K
  • GravitateMediaGroupGravitateMediaGroup

    why can't you show actual product I also use vegas and may be able to help the while balance at the bottom of the effects menu doesn't work?

  • RamboRambo

    The end result I need is an even white background without losing much detail, this is the Untouched clip from the camera shot at 720p 50 fps. The product is unreleased so cannot be shown. Sony Vegas white balance in V12 helps but no where near as much as 2 levels of grad exposure in Magic Bullets.

  • GravitateMediaGroupGravitateMediaGroup

    ok, so mask it, color the outer section with whatever works best, then color the middle sections with whatever works best

  • RamboRambo

    I'm looking for other ideas other than masking, there is too much complex motion in the video to mask, thanks anyway for the suggestion.

  • GravitateMediaGroupGravitateMediaGroup

    i think you may just have to live with what it is multiple shades of lighting will be tricky to manipulate

    maybe just throw the sin city effect on it? lol

  • RamboRambo

    Ok no cigar for you ..lol

    The type of thing I'm looking for its a reverse (white) luminance/exposure vignette closely matching the lens fall off, the centre 1/4 of the frame has reasonable exposure, so if a reverse vignette was applied to the rest, a general lift would improve the centre and Neat video would take care of any noise. There are only two colors in the masked area, solid red, skin tone and of course black and white. Skin tone is not that important, the white and red product is.

  • RamboRambo

    All sorted, as usual I found a solution myself. Must have been too hard for all the effects gurus on this board. Thanks to the one person that at least had a crack at it.

  • GravitateMediaGroupGravitateMediaGroup

    sometimes it just takes a little experimenting with various effects

    what end up being the process to your fix?

  • jpbturbojpbturbo

    I would duplicate the layer and punch a feathered hole in the middle with a mask and then adjust brightness and the size of the mask until it looked right.

    AE would be perfect for this.

  • RamboRambo

    That's what i ended up doing jpbturo and then removed any leftover with two Grad Exposures one left and one right. Neat video and the skin corrector in Magic Bullets Looks "Cosmo" fixed the face. Now looks identical to the rest of the correctly exposed shots at closed down apertures.

    I shared this as a warning the small glass size on the 20mm pancake wide open can cause large edge light falloff if you're not careful with exposure.

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