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Panasonic LX100 "Invalid area" in Raw files

Discussion in 'Panasonic Chat' started by Eye Robot, Jun 25, 2015.

  1. Eye Robot

    Eye Robot Well-Known Member

    Using Silkypix as developer, and using the Trimming Tool (ie Crop) there is an "invalid area" - a margin of perfectly useable pixels on all 4 sides of the image which is not normally visible, but can be added to the picture on clicking the right button and stretching the trim area.

    The amount varies - it can be as little as 10 pixels or fewer on each side (ie practically non existent), or it can be as much as 120 or more pixels on each side. In an example this was enough to put back the cross on the top of a steeple which I had thought I had missed and was about to dump the image.
    It may also depend on whatever aspect ratio chosen, but I took two photos yesterday both on 4x3 a few minutes apart, and some had a 3-10 pixel margin but another a 120 pixel margin.

    If using old version of ACR (I have to convert to DNG first) you are given no option to recover the missing pixels.


    So questions:

    Is this true of all Raw images of whatever variety?

    Why does the invalid but recoverable area vary between photos?

    Can they be recovered in Lightroom

    Do people generally know about this.

    Do any forumites use Silkypix. (Let down by poor translation of help from Japanese)
     
  2. El_Sid

    El_Sid Well-Known Member

    I've not encountered the phenomenon you describe but most (all?) cameras seem to have a total pixels and effective pixel spec. As I understand it the pixels not included in the effective value are used in calculating colour balance and the de-mosaicing algorithim. It appears that Silkypix includes them in the conversion but doesn't treat them as part of the 'true' image

    Could be connect to the de-mosaicing routine - the complexity of the image may determine how many pixels are needed to calculate an accurate conversion.

    Probably not, like PS LR uses ACR to convert the images. My version of ACR delivers exactly the image size quoted by the maker for the camera (Nikon or Canon in my case) - no more no less - and I suspect the same would run true for a Panasonic image

    Unlikely. It may just be an oddity of the way Silkypix works. I've run NEF and CRW/CR2 raw files through View NX2, Canon DPP, ACR, RawShooter and Raw Therapee and never seen this effect - what you get is all you get and nothing extra with any of them.

    When it saves a picture it's a bonus otherwise...
     
  3. Eye Robot

    Eye Robot Well-Known Member

    Ok, Thanks Nigel

    As you say, it is a bonus, and the advantage of using Silkypix.

    I might have figured it out (almost)

    The sensor on the LX 100 is actually larger than the pixel count of images
    (you can select different aspect ratios)
    example a 4 x 3 ratio image is 4112 x 3088
    but 16 x 9 is 4480 x 2520.

    If the sensor is 4/3 in shape it implies the actual count is something like 4480 x 3360, which almost exactly explains the maximum margin that I can recover on some pictures (4480-4112)/2 = 184

    What is doesn't explain is why I can't recover it all on every image, only some of them. The only thing I can think of is it depends on the amount of zoom being used on a particular image.

    Maybe there are some other LX100 users who experience similar. There ought to be because Image quality is great.
     

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