What you see is what you get with adapted lenses?

Discussion in 'Adapted Lenses' started by super8man, Jul 8, 2013.

  1. super8man

    super8man Mu-43 Regular

    Jun 17, 2013
    I am curious about in-camera processing of images (presumably prior to the image being created as a RAW (ORF) or JPG image on your memory card).

    My question is, what exactly is the camera doing prior to giving me what I want to see. As I understand it, the internal "IQ" of the camera is showing me what it thinks I "want" to see instead of giving me what my sensor actually saw. Yes? No?

    I have read on mu43 that the camera makes "corrections" for lens "errors", assuming this is referring to native manufacturer lenses sold as a system.

    So, in short, is the camera doing any processing when being served with image information coming from adapted lenses? And if so, what is the IQ doing? Is it removing tiny bits of perceived chromatic aberration from the pixels?

    I don't want to sound old ("Get off my lawn!") but I want what I think I saw! LOL. Just asking questions here...I love m4/3 and all forms of photography. I just wonder how much the camera is telling me a few white lies now and then?


  2. nsd20463

    nsd20463 Mu-43 Regular

    Apr 30, 2011
    Santa Cruz, CA
    In-camera corrections are only for native lenses. The lens contains the correction data, which the camera reads. Non-native lenses lack this data (and except for 4/3 lenses, lack any electrical data connection at all)

    What you get in the raw file is what the lens projected onto it passed through the sensor's hardware, with the configuration (ISO and IBIS) you the user selected.

    Incidentally the same is true for the raw file with native lenses. It does not contain CA, distortion or vignetting corrections. The raw file does contain the information as to how to correct the image, which is meant for the raw image development software. Most popular commercial raw developers won't let you disable the corrections, so the end result is essentially the same to the user. However all the open source ones will let you see the real raw image (and in fact don't decode the proprietary information at all).

    The jpg is more variable, since the camera.whatever the camera is set to do at that time. WB, film modes, sharpness, contrast curves, and the rest of the raw->jpeg conversion options you can set in the camera come into play. This happens no matter the lens.
  3. phidauex

    phidauex Mu-43 Regular

    Jun 17, 2013
    Boulder, CO
    True - it is basically "what you see is what you get". The only exception I can think of are if you have "Live Boost" or equivalent feature turned on, which increases the gain of the display for dark areas. If you are shooting RAW that is all you get. If you are shooting JPG it naturally does WB, sharpening, and other settings, but they work the same as in a native lens JPG.

    No CA or distortion corrections will be applied.

    I have noticed that occasionally when stopped down, non-native lenses have slightly unreliable metering. My assumption is that with native lenses, the camera meters wide open, then stops down to take the photo, while in adapted lenses, the camera must meter and shoot at the stopped down value. Less light hitting the sensor = less accurate metering. In practice this means that I occasionally see slightly underexposed images (compared to what I thought I was going to get) when stopped far down.
  4. super8man

    super8man Mu-43 Regular

    Jun 17, 2013
    Thank you, that makes a lot of sense. I had forgotten about the lens connections as far as processing is concerned. Fascinating stuff. Thanks again!