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Finding Face Exposure on GH2
  • New to the camera.
    With video cameras, I usually expose faces to 75%IRE, using zebras set to 75.
    How can this be done on the GH2. Record Highlight is locked at 100%, no? I've never used a Histogram and will study it if that's what people use for accuracy.
    Thanks!!

  • 65 Replies sorted by
  • You can't do this on the GH2. The 'zebra' function isn't a traditional zebra, it simply flashes overexposed areas white. You can use the histogram and a 18% gray card to fill the screen and show the skin tone level.

  • I'm not sure, but what about spot metering, aiming for the skin and dialing in a white histogram?

  • An 18& gray card and spot metering works pretty good too. I use it sometimes, but I find the best way to me is to use a light meter.

  • I use spot meter all the time. My default.

  • For me the easiest, quickest (default) is to keep the GH2 on spot and hit whatever's about 18% grey in the shot I'm shooting, realizing of course that the spot follows the auto focus as well. So when using the touch screen- I touch for focus to frame and see the shot; then touch for exposure; then touch for focus again and then shoot. Focussing manually you can just touch your old spot metre all over the place and giggle.

    But it's very subjective. Personally I don't find the histogram as helpful as I had hoped. It tells me what my eyes already can see in the LCD, which for me is pretty good for lighting but useless for focus. But if I was actually lighting a scene (and not just shooting what's in front of me) then I'd use an incident light metre.

    But if I had to pull focus, well, I'd either pray, buy a monitor and all that, or hire a guy in a team as part of a crew that deserves to be paid as well as the catering truck that's required to feed 'em!

    So I prefer the prayer option, obviously, knowing that if I was to ever screw up I can always run away and cry, believing that some kind of entity beyond the somewhere and when might love me anyways. Maybe

  • 18% gray card + spot metering then what?

    Set one of Custom WB Preset 1/2/3/4 on the gray card?

  • I have a gray scale card with 20 steps. It has A mark on step 0 (100%), M mark on step 7 (65%), and B mark on step 16 (20%).

    On GH2 with spot metering, M mark gave the most dynamic range. Set EV to 0 based on the M mark. Then EV reading on the skin was 1 1/3 which is my target.

  • When using an 18% gray card, remember to compensate by 1/2 stop. DSLRs are calibrated for 12% gray.

  • That's a 1/2 stop -open- . (Drat, need even more light...)

  • Don't over think it. Since I was a kid shooting Kodachrome I just took a reading off the back of my hand (white guy with a tan = 18% grey)

  • Sure. That said, with the DR and low light noise/banding of a GH2, I often find it's better to shoot gray for reference and color correction but push the exposure as far as possible to the right on the histogram until just the smallest specular highlights are clipping.

    It all depends on the shot, but the thing to remember is that you can expose the shot the way you need and bring the footage back into like in color correction. The gray card or color bars can also be a post-production tool.

  • Actually that's pretty good idea... to record gray/color cards.

    About the highlight clipping, yes it depends.

  • Basic question, so bear with me - when exposing using a grey card, is exposure correct when the histogram turns white?

  • @mrbill

    Deliberately overexpose, then see what color it turns. Whatever is the opposite is your answer.

  • I have been approaching the same way I do stills. I shoot a short test then play back in camera and check the histogram there, I guess it's a bit long winded but I find the active histogram confusing. I would be interested to hear others thoughts on this.....

  • I try to get my skin tones (or subject areas) within EV0 to EV+1 1/3, and keep the highlights under EV+3 and shadows over EV-3.

    If the shadows are under, I need to light, if the highlights are over, I need to block. If I can't light, or block, I choose which ever option is best; crush, blow or push, which depends on the scene.

  • Anybody else finding that the new hacks throw the in-camera meter off by an entire stop? +/-0 on gray card reads 40% on waveform monitor in every film mode except nostalgic, which reads the appropriate 50%....or did I miss this on Quantum? It seemed to be accurate on Quantum, but Sedna is a full stop under using spot meter mode, filling the frame with the card, and adjusting till meter reads 0.

    same results in both tungsten and sunlight

  • @shian Yeah, I noticed it, too. Not sure it started with Sedna or earlier. I kind of think GH2’s metering is a bit wonky (to put it mildly).

  • @shian and @Mr_Moore

    I have just tested it and it is at 40% with +/-0 on gray card.

    What should be the correct value in Waveform?

    f1.4-iso640ev+-0-ss50.PNG
    1306 x 803 - 528K
  • ...and here is one underexposed by one stop.

    f2.8-iso640ev-1-ss50.PNG
    1295 x 809 - 507K
  • +/- 0 should be 50%. Turns out its a DSLR camera thing. Every DSLR does it. I'll cover the specifics in the CG Film School. It's a different curve on every film mode. Nostalgic boosts shadows and mids so that it reads 50. But highlights blow really fast above 70.

    U also have to angle your gray card correctly to get an accurate reading.

  • Cinema film mode doesn't seem boosting the shadow.

  • Cinema doesn't. Cinema actually lowers the shadows but retains highlights better.

  • @Shian

    Thank you and what should be the correct angle to get the correct reading? Also, I was under the impression 18% grey cards should fall at exactly at 46%. Does this mean I have to overexpose by +- 1/3 or +-2/3 depending on the situation.

  • basically, yes. I usually go with 2/3.

    The angle should bounce the brightest light (or the sun, if illuminating the subject) into the lens.