ACR / RAW Plugin 3.3 Out + Interesting Gamma & RAW Primers

Discussion in 'Digital SLR' started by C J Southern, Jan 21, 2006.

  1. C J Southern

    C J Southern Guest

    Hi,

    Whilst researching an interesting point John Sheehy raised this morning, I
    make the discovery that v3.3 or ACR / RAW Plug in is now available from the
    Adobe site.

    John raised the point that in converting files to DNG format Black Masked
    Pixels were stripped from the conversion - it appears that this was the case
    up to and including V3.1 - however Thomas Knoll (god-the-creator of
    Photoshop) stated that they were planning to include this data in V3.2
    (whether they did or not I don't know).

    For all of those confused by the issues of linear gamma as it applies to raw
    captures - and raw captures themselves, I discovered a couple of 4 page pdfs
    on the Adobe website that were written by Bruce Fraser (even includes a
    photo of the handsome devil!) - they're basically excerpts from his camera
    raw book, if anyone's interested in pre-viewing his writing style ...

    www.adobe.com/products/photoshop/pdfs/linear_gamma.pdf

    www.adobe.com/digitalimag/pdfs/understanding_digitalrawcapture.pdf

    Those interested in reading about the initial issue John raised can find
    some info here ...

    http://photoshopnews.com/2005/05/23/dng-workflow-part-i/

    And the closest thing from Adobe to suggest that it's not an issue anymore
    here ...

    http://adobe.groupbrowser.com/showpost57621-.html#post57621

    Happy reading everyone :)
     
    C J Southern, Jan 21, 2006
    #1
    1. Advertisements

  2. C J Southern wrote:
    [snip]
    There is more about this in the DNG specification:
    http://www.adobe.com/products/dng/pdfs/dng_spec.pdf

    Appendix A: Compatibility with Previous Versions
    Compatibility Issue 1: ActiveArea Tag

    "The ActiveArea tag was added to the DNG specification in version
    1.1.0.0. Previous versions of the DNG specification do not support
    storing masked pixels. DNG writers should set the DNGBackwardVersion to
    a minimum of 1.1.0.0 if the masked pixels are stored in the DNG file."

    (And there is more in pages 12 and 41).

    I have no separate specific confirmation that they have now changed to
    this version. But there IS indirect evidence. ACR 2.3 appears NOT to
    support (some? all?) DNGs written by version 3.3, but it DOES support
    (some? all?) DNGs written by version 3.1. It was ACR 2.4 that was
    updated for the new version of the specification, and that DOES support
    both version 3.1 and 3.3 DNGs.

    So it certainly appears that 3.3 writes a different version of DNGs
    from those written by 3.1, and this a version that ACR 2.4 supports but
    ACR 2.3 doesn't. (I didn't check what 3.2 did. It doesn't matter any
    more).
     
    Barry Pearson, Jan 22, 2006
    #2
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.