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Gx7 i.Dynamic+i.Resolution vs Raw

Discussion in 'Panasonic Cameras' started by tino84, Apr 22, 2015.

  1. tino84

    tino84 Mu-43 Veteran

    217
    Dec 29, 2013
    Hi,
    I shooted my day @ Ljubljana yesterday, with my gx7.

    I usually use raw and then save jpg with Rawtherapee, adjusting exposure and contrast.
    I was thinking ALL settings as also i. Dynamic and i.Resolution would affect only jpegs, so I forgot both to high.

    Yes, both affect Jpegs, but i.Dynamic also affects Histogram and Exposures, because it tricks normal exposures.. You're thinking you got it well, than you see your raw, and it is... underexposed (if sunny), a lot, even to -2Ev. There's no way you can recover well higlights starting from -2ev..

    But if you loose Raw, you can see Jpegs..
    Jpegs are sharp, crispy and detailed, and good thing, you can manage some highlight recover with Rawtherapee

    Here two ex. where you can find raw, original jpeg (yes, it is small..), jpeg from raw, and little adjustment on jpeg with rawtherapee.

    https://www.dropbox.com/sh/hgi1t1c2m6a1xmx/AAADWRaLTW1P6DE4nONmgZ-Fa?dl=0

    PS: The strange thing is you see Jpeg good, but histrogram showed on Rawtherapee (or another editor) would be.. low. Not flat, not good, just.. little
     
  2. Klorenzo

    Klorenzo Mu-43 All-Pro

    Mar 10, 2014
    Lorenzo
    I did not know that i.Dynamic can change exposure but it makes sense.

    Two stops are not much to push back with raw files, using a mix of exposure compensation, levels, tone curve and highlight&shadows recovery:


    The histogram can go "flat" or very low if you work too much on levels, saturation and other things.
     
  3. tino84

    tino84 Mu-43 Veteran

    217
    Dec 29, 2013
    Cannot see pics you posted, but with my pics, it's easier to make original jpeg better, than recover raw and make it detailed and sharp as original jpeg
     
  4. David A

    David A Mu-43 All-Pro

    Sep 30, 2011
    Brisbane, Australia
    The camera HAS to perform a RAW conversion in order to show you something you can understand in the viewfinder or on the camera's screen. The light meter part of the firmware operates after the conversion is done and is based on the conversion. Even if you're shooting RAW, the camera uses the JPEG image it generates for the viewfinder/screen for the light meter data.

    Any settings which affect JPEG file conversion are also used to generate the viewfinder/screen display image. What this means is that all JPEG settings can influence the meter reading, even if you're shooting RAW. This is true for all M43 cameras, both Panasonic and Olympus alike.

    Here's a link to a blog post by Pekka Potka a few years back: Expose to the right, ETTR - with E-P3 — Pekka Potka

    It's about exposing to the right with the E-P2 but he discusses the differences between RAW and JPEG when it comes to exposure, how JPEG settings affect the light meter, and recommends some JPEG settings that made the meter a bit more accurate if you were shooting RAW than the default neutral settings. I think there are differences between Panasonic's JPEG settings compared to Olympus, and the Gx7 has a lot more modern sensor than the E-P3 with a wider dynamic range amongst other differences. Portal's setting recommendations probably won't be of much value for you as a result, or even perhaps of much value to someone with a current Olympus body given the sensor and firmware changes since the days of the E-P3, but the article should give you a good general idea of what's going on and why the behaviour you're noticing is happening, and perhaps give you some ideas on what else you can do to make the meter a little more reliable when shooting RAW.

    What I ended up doing, which you can try, was to take a lot of test shots of a piece of white paper placed on the ground out in the sun. I varied the exposure using the exposure compensation dial from shot to shot and took notes of when the highlight overexposure blinkies started to appear on the paper, Then I processed the files so as to recover any blown highlight area on the paper and noticed at what exposure I could no longer recover blown highlights and compared that exposure to the one in which the blinkies started to appear on the camera. That told me how far I could push my exposure without losing highlights.

    That's a good and reliable method of working out how to use your camera's meter and the result will be reliable PROVIDED you don't change the camera's JPEG settings because that may change the meter's sensitivity. You will also have to repeat this test if you start using a different camera because results will change if you change the sensor and/or the camera's firmware.

    Hope this helps you understand what's going on a little better.
     
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