Panasonic GH2 ETTR

Discussion in 'Panasonic Cameras' started by Boatman, Sep 19, 2011.

  1. There have been numerous posts commenting on the fact that the Panasonic m43 cameras tend to underexpose images. Following the philosophy of ETTR (expose to the right), I very frequently add two to four EV clicks (1/3 EV each) to my images. This pushes the brightest part of the histogram right up snug to the right side of the graph. Doing this means that I'm getting the maximum amout of data for post-processing manipulation. (An excellent article explaining the reason for doing this is posted on the Luminous Landscape,

    However, when I review the images captured by this method in the camera using the histogram display, none of the color graphs seem to get into the upper 1/4 of the graph. Frequently, they are mostly in the lower half of the graphs, even though I exposed using ETTR.

    My question is, is the pre-shot histogram accurate? Has anyone tested what happens if you deliberatly over expose by a fraction of an EV, or has anyone done any meaningful comparison of the exposure levels in Photoshop or other PP software? Or, am I just misunderstanding something about the graphs?

    Bottom line, I'm getting good exposures, but I wonder if I'm maximizing the potential of the camera.
  2. dayou14

    dayou14 Mu-43 Regular

    Jul 6, 2011

    I have the same experience. My GH2 is always +0.33 or 0.66 EV more than correctly exposed, but when I call up the pics in Aperture, the pics still look dull or maybe even under-exposed. I don't dare to go more, but listening to you now, I think maybe I'll try 4 clicks to see what happens.

  3. nickthetasmaniac

    nickthetasmaniac Mu-43 All-Pro

    Jan 11, 2011
    Out of interest, are you shooting RAW? If you are, then the histogram you're getting in the camera is from a jpeg processed in-camera, which naturally doesn't have as much headroom as the RAW file.

    Therefore, when you stick it on the computer and see the actual RAW file (or at least a proper process of the RAW file) the histogram may 'magically' move to the left.
  4. I nearly always shoot in RAW + JPG, which was the case this weekend. I’ve not really monitored what my histograms in Photoshop look like, though I use the curves tool frequently. I just need to pay more attention.

    I think a series of controlled photos is in order. I’ll try to set up some shots using a second camera to photograph the pre-photo histogram and the post-photo color graphs. I can also take screen shots of my computer screen for Photoshop for comparison.

    Does anyone know if the Highlight feature works in still photo mode? I use it in video mode, but have never seen a setting to turn it on for stills. If it does work with stills, perhaps an ‘adjust to the left’ from a flashing screen could be used instead of ETTR using the histogram. More or less accurate? I don’t know. I’d have to try it out.
  5. Tom Swaman

    Tom Swaman Mu-43 Veteran


    Yes, the highlight feature works in still photo mode.

    Best regards,
  6. ETTR - Highlighting

    Correct. I tried it last night. But it won't do what I proposed. It only shows the blown out areas in the image playback, not when you are composing. It is useful, but not as useful as if you could see the flashing before the shot. If you are doing ETTR, there is a pretty good chance you are going to blow some small, very bright areas and the histogram will show that, too.

    I took a few shots last night and compared the preview histogram to the playback graphs. They are actually quite similar in range. I think it boils down to the fact that if you really want to maximize your exposure to the right you have to adjust the EV for each and every shot - even within a sequence in similar lighting.

    There was another piece on Luminous Landscape, Optimizing Exposure, that discussed the fact that using film camera metering techniques in digital cameras (which is what all current digital cameras do) is the wrong way to go about it. Digital cameras should meter off the histograms and automatically expose to the right, then adjust the JPGs for brightness. I think what we are seeing is just reinforcement of this fact. Digital camera makers are eventually going to figure this out, but I'm not holding my breath for a fix to come out in some future release of the firmware for a GH2.

    Bottom line, keep your eye on the histogram and ETTR using the EV thumb wheel.