Exposing the GH4

Most advice regarding exposing digital cameras centers around protecting highlights. In general, this is good advice because if you blow out highlights,  that information is well and truly gone. There is nothing that can be done in post to recover it. Because of this fact, I tend to error on the side of under-exposing my images.

This rule of thumb is so ingrained into my thinking and workflow that it’s taken me far too long to realize that exposing to the left is a dangerous strategy when shooting with the Panasonic GH4.

Good exposure is good exposure, but at the fringes, some sensors are more forgiving of underexposure, and some deal better with slight overexposure. Because the latitude for a good exposure is so slim on most affordable DSLR style cameras, it’s very important to understand in which direction you should lean when you have to compromise. And in any scene with wide dynamic range (very dark darks and very bright brights) you’re going to have to compromise.

With the GH4, it is very clearly advisable to error on the side of overexposing. (“Exposing to the right.”) The reason for this is two fold:

  1. Underexposed shadows are very noisy and look quite bad when raised in post.
  2. Color accuracy suffers significantly in under-exposed midtones, and is very difficult to correct in post.

As usual, pictures demonstrate this much better than words. The following are still grabs from the same take. All of the camera settings are exactly the same, the only thing that changed was that I manually adjusted my aperture.

Proper exposure

Proper exposure

Proper exposure

Under exposed

Under exposed

Underexposed

Pay particular attention to the groom’s jacket and the bride’s skin. Despite using every color correction trick in my toolbox, the the best I match I could create leaves the underexposed shot clearly subpar.

Quick tips

  • The GH4’s exposure meter is pretty good. Keep your eye on it. If you can hit zero, do it.
  • If you must underexpose (to save the sky, for example) do so at the bare minimum that protects the highlight.
  • Cine-style lenses with de-clicked aperture rings are helpful in dialing in exact exposure.
  • Variable ND filters give an extra level of fine grained exposure control, while leaving other camera settings intact (shutter speed, etc.)

8 Replies to "Exposing the GH4"

  • Manny L.
    June 21, 2015 (1:54 pm)
    Reply

    Thanks Joe for sharing this! It has always confused me as to why some takes would look like they were shot on a diffrent profile setting.

    • joe12south
      June 21, 2015 (2:19 pm)
      Reply

      I’ve never used a camera that was this sensitive to correct exposure. It’s very unforgiving. I really hope that the GH5 utilizes recent technology advances to squeeze a better SN ratio out of that small M3/4 sensor.

  • sam holder
    June 22, 2015 (8:53 am)
    Reply

    I find the same rule applies when I shoot Magic Lantern Raw on my 5DmkIII. I do much better if I overexpose just a bit. Underexposure kills me with noise especially in the blue channel. Thanks for posting this article about the gh4.

  • davidp158
    July 31, 2015 (7:01 am)
    Reply

    I’m very confused by the color shift of the groom’s jacket. I have never seen such a radical shift in neutrals due entirely to exposure? Did you color correct either of these images? If so, the comparison is pointless.

    • joe12south
      July 31, 2015 (8:11 am)
      Reply

      The groom’s jacket was not neutral, it was navy blue. But when underexposed, colors tend to “wash out”, and of course have a higher SNR, thus it went grey. These samples have been corrected to match…the difference straight out of the camera is even more pronounced.

  • Jack McKinney
    October 7, 2015 (11:15 am)
    Reply

    This is precisely the issue that I have had with mine the most. I find it particularly unforgiving in Cinelike V though I can’t say exactly why without doing some testing. Muddy skintones are my biggest issue. It’s a shame because folks look at footage from the GH4 online and think that it is representative of what the camera can do which, as it turns out, isn’t really the case. Great informative article as usual.

  • Val
    May 3, 2016 (9:52 am)
    Reply

    Awesome advice, thanks. Perhaps that was one of the reasons for horrible skin tones, specially in CineD.

  • Zade Cross
    June 24, 2016 (7:17 am)
    Reply

    Nice one Joe, very helpful!


Leave a Reply