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i.dynamic behavior: it just works good with M43 lenses, does not work with Nikon and Canon FD lenses
  • apefosapefos

    I did a careful test to discover what is the thing that makes i.dynamic turn on in GH2.

    I tested contrast scene with shadow / highlight areas, just shadow areas alone in the frame, and just highlight areas alone in the frame. I also tested same situations with the three different light mettering and different iso, shutter speed, aperture.

    What I found is: the camera does not take into account the differences in shadow/highlight areas to turn it on, and the mettering type, iso, shutter, aperture does not influence it also.

    What makes i.dynamic turn on is some amount of overexposure. It does not matter if the mettering is showing underexposure (if you put the spot meter in the shadow area), but if there is an area in the frame big enough to camera consider it an overexposure in some area of the sensor the i.dynamic turns on. It turns on even in a white wall if you overexpose it a little. The i.dynamic does not lock when hit record, it keeps in auto mode. So it is impossible to use it, because nobody will overexpose some area to get it on.

    If the hack could make the camera feel an overexposure even if there is not (a false overexposure information to camera), the i.dynamic would be keep enabled.

  • 10 Replies sorted by
  • mpgxsvcdmpgxsvcd

    Are you sure about that? In the GH2 Setup guide it shows how yes there needs to be an overexposed area but there also needs to be an underexposed area as well. I.dynamic does not affect the overexposed area. It can only bring up the exposure in the underexposed area. It does not bring down the overexposed area at all.

    http://www.youtube.com/watch?feature=player_detailpage&v=uROQbbiiO2I#t=89s

    Can you show us a video where the I.dynamic feature affects an overexposed area?

  • apefosapefos

    @mpgxsvcd yes i am sure. let me explain it better.

    First yes, it does not bring down the overexposed area. It only bring up the underexposed area. But this would be useful to get better shadows area if we could make it enabled all time.

    I tested it with GH2 pointed to a white wall. so i started with the image underexposed and start to open the aperture / change the iso / change shuuter speed. when the image start to get overexposed the i.dynamic turns on. and when I go back and expose correct it turns off.

    I did the same test in an image with highlight and shadow areas. If the highlight area is correct exposed the i.dynamic does not turn on even if the shadows are dark. It just turn on when the highlights area become overexposed.

    Same test with just a shadow image without highlights in frame. i.dynamic turns on when I open the aperture and low the shutter speed to make the image overexposed.

    It does not matter if I point the spot metter to the highlight area or to the shadow area. It does not matter if I use the other mettering options. The i.dynamic just turn on when there is an overexposed area in the frame.

    So i believe the GH2 does the wrong job. If the i.dynamic does not bring down the highlight areas why enable it when the image get overexposed? It would be better the camera enable it when the camera feel there is an underexposed area in the frame to bring it up. The camera is doing the reverse from what it need to do.

  • mpgxsvcdmpgxsvcd

    @apefos

    Ok I see what you have done. However, I disagree with the testing method that only uses a white wall. It sounds like you are testing the i.dynamic feature on a scene that has uniform exposure? If so then yes it will require you to overexpose to trigger the function. However, it will also require that there is an under exposed area as well.

    A uniform exposure is not what the function is intended for. It is intended for scenes with high dynamic range where one portion of the scene is greatly overexposed and one portion is under exposed. It will raise the shadow detail to compensate for the underexposed scene.

    It makes sense to only trigger i.dynamic when there is an overexposed area because this is meant to be a "dynamic" feature. It is intended for use when the dynamic range of the scene exceeds that of the camera. When that occurs(which is actually hard to reproduce) then it compensates for that.

    If your image is uniformly underexposed then you simply need to turn the exposure up. The error there is user error not a camera malfunction. The whole intent of the i.dynamic feature is to compensate for the GH2's complete lack of dynamic range in jpg and movie modes. It is the absolute worst camera dpreview has tested for dynamic range and the i.dynamic feature doesn't really help since it is so hard to trigger.

    Check out the image below to see how good dynamic range enhancers preform.

    DR Comparison.jpg
    1920 x 1080 - 176K
  • apefosapefos

    @mpgxsvcd you did not understand it yet.

    I used the white wall and the shadow image to test when the camera enable the feature. I will try to explain again using the shadow/highlight image:

    ok, there is a shadow/highlight image, a dark tree against a sky. And the GH2 i.dynamic bring the shadow up, it does not bring the highlight down. So what to expect from the feature is:

    I will do a correct exposure to the sky and I will expect GH2 will enable the i.dynamic to bring the dark tree up. But this does not happen, i.dynamic will not be enabled.

    If I overexpose the sky a little the i.dynamic will turn on, but this makes no sense, because i.dynamic will not bring the sky down.

    What I am trying to say is: the camera is enabling the i.dynamic in the wrong moment.

  • mpgxsvcdmpgxsvcd

    @apefos

    No I get what you are saying and I am saying that it is not designed to do that. This is not trying to maintain exposure. It is trying to expand the dynamic range of the camera by increasing the shadow exposure only when the scene warrants it.

    Basically, it waits till the scene overexposes "AND" underexposes. I think you need to try your experiment again. I just tested it by shooting a very bright light that completely fills the screen. While the i.Dynamic mode was showing that it was on, it was not showing that it was active(Yellow color) because there wasn't an under-exposed area to raise the level of.

    I then pulled the camera back slowly to fill less of the screen with the bright light and more of it with the underexposed background behind the bright light. Once I reached about 50%:50% between over and under exposed the i.dynamic yellow bricks lit up and the under exposed area brightened up.

    If you want the i.dynamic mode to decrease the highlights then you need to manually adjust the overall exposure down and let the i.dynamic feature do what they intended it to do which is raise the shadow level.

    I just tested it again by filling half the screen with the bright white background in my computer monitor and the surrounding dark scene. As I decreased the exposure the bright white screen became less bright until the camera was showing that the scene was properly exposed and the I.dynamic feature was still working(Showing up as yellow).

    Then I tried increasing exposure until both the white computer monitor and background were over exposed. Once I hit the point where there was no underexposed area and only over-exposed area the yellow indicators turned white showing that the camera will shut off the i.dynamic feature if everything is over-exposed.

    I am not saying that their implementation is desirable. However, it does do what they intended it to do which is raise the shadow level. Hopefully the GH3 will raise and lower the shadow and highlight areas respectively but I am not counting on that.

  • mpgxsvcdmpgxsvcd

    I don't have my second camera right now to demonstrate this. However, I will post the video showing this when I get home with my other camera. You can clearly see how the i.dynamic feature will only trigger when the highlights and shadows in the histogram are clipping. It will not trigger if either one or both of them are not clipping.

  • apefosapefos

    @mpgxsvcd Hi, I found the problem.

    The i.dynamic works great with the Lumix 14-42mm kit lens. But it does not work good with legacy nikon and canon fd lenses. The tests I did was with Nikon and Canon FD lenses and the i.dynamic just enable when there is overexposure. With the Lumix lens the i.dynamic works great and enables without overexposure. It seems the camera needs the aperture information from the lens to i.dynamic works properly.

  • mpgxsvcdmpgxsvcd

    @apefos

    That is entirely possible. Metering works with MF lenses. However, it only works correctly in some modes. For instance it won't work at all in shutter priority mode. It doesn't work consistently in Program mode either.

  • apefosapefos

    @mpgxsvcd

    I did try the i.dynamic with Nikon and Canon FD lenses in M, A, S and P modes, and also in the three metering options, none works. It just works with the Lumix lens.

  • mpgxsvcdmpgxsvcd

    @apefos

    I sold my MF lenses so I can't test it.

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