1. dcpTool has been available for quite a while as a command line application for Windows and the Mac. But now it available in the form of an easy to use Mac app, with powerful batch processing capabilities. dcpTool for the Mac is available from the App Store.

    dcpTool allows you to:

    1. Decompile DNG Camera Profile (DCP) files in XML. The XML can then be read and edited with a simple text editor.
    2. Recompile edited XML into DCP files
    3. Remove "Hue twists" from camera profiles. 
    For more information on hue twists, see these posts:
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  2. Many cameras embed lens corrections into raw the raw files that they produce. Generally, that's a good thing - straight lines stay straight, etc. For an example of lens corrections in practice, take a look at this post about the Leica SL.

    But, as the saying goes, "there is no free lunch". Lens corrections also have some downsides:

    • Lens corrections result in a small reduction in sharpness. Sean Reid, at Reid Reviews has done extensive testing on this as part of his various lens reviews, and his conclusions are clear - there is a measurable loss in sharpness.
    • Lens corrections result in some reduction in image size - the corrections inevitably result in the edges of the image curving, and the curved parts need to be trimmed off to get back to a straight edge.
    So sometimes, it's useful to be able to get an uncorrected image. Now there are some raw developer apps that allow you get to uncorrected images (AccuRaw EXR is one of them), but most mainstream apps such as Lightroom and Photoshop don't allow correction to be disabled.

    Fortunately though, there is a "simple trick" that will allow you to disable lens corrections for nearly any camera that produces raw images. What you need to do is a simple two step process:
    1. Firstly, convert the raw image to a DNG image, using Adobe's DNG converter.
    2. Then use DNG Cleaner (macOS only) to remove any opcodes.
    The resulting DNG will not have any lens correction, and you can load it into Lightroom, Photoshop, or any other app that supports DNGs.

    Why does this work? This works because whenever DNG Converter converts an image that needs lens correction, it embeds the required correction as an "opcode" into the DNG image. Lens correction opcodes as usually things like "WarpRectilinear". DNG Cleaner knows where to find these opcodes, and simply removes them, as long as you have the "Remove opcodes" checkbox selected:


    Note that in order for this to work, you need DNG converter to be using it's default settings. Specifically, Compatibility should be set to the most recent version of Camera Raw. You should definitely not be using Custom Settings with the "Linear" checkbox selected. "Linear", otherwise known as LinearRaw, bakes any corrections into the actual data in the DNG, making it impossible to remove.

    There's more information on the DNG Cleaner website.
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  3. Those of you that have read the Leica M10 raw file analysis post will know that M10 DNGs have more baggage in them that is typically the case for a Leica DNG. I've put together a little app to clean them up, called DNG Cleaner (Mac only for the moment). For M10 DNGs this will remove:

    1. The full size image preview - that will save about 3MB
    2. The various Lightroom/Photoshop adjustments embedded in the XMP portion of the DNG - ISO dependent noise reduction settings, lens profiles, etc

    DNG cleaner will also optionally remove opcodes, and apply lossless compression. This isn't relevant to the M10, but in many other Leica cameras, e.g., the Q, the SL, etc, opcodes are used for lens correction. For an example of the SL's with and without lens correction, see my post on the subject. DNG Cleaner is what Sean Reid used to remove opcodes for his SL 50 review, which some of you will have seen.

    As ever, back up your files before using any app that is designed to modify them.

    For more information on DNG Cleaner, see the website.
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  4. AccuRaw users might have gotten a bit of a surprise recently - AccuRaw has turned into AccuRaw EXR, and is now at version 3.

    The reason for the name change is that the focus of the AccuRaw product has changed a bit, based on what users were actually doing with it. AccuRaw has always been focussed on having highly linear color response, with no "hue twists" or other surprises in the color rendering. As it turns out, that is a very useful feature to have if you're composting stills into video - it reduces the amount of work required for color matching.

    In the world of video, especially in the professional cinematography world, the "gold standard" is to use a format such as EXR, which is a floating point format. That allows huge flexibility in the way that post processing is done. So the new version of AccuRaw, now named AccuRaw EXR, supports EXR output.

    However, it's more than just a name change. In order to really support EXR output, AccuRaw has seen major changes internally - it now has a fully floating point, non-clipping workflow. For more on why that is important, see this post.

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  5. Good news - AccuRaw, AccuRaw Monochrome and PhotoRaw now have support for the compressed raw format that Fuji use in the new GFX 50S. Previous versions of AccuRaw/PhotoRaw had support for the regular uncompressed RAFs, but not the compressed version. That's now resolved, and any GFX 50S file should now work. This is thanks to Alexey Danilchenko and the folks over at LibRaw, who added support for Bayer compression to their previous X-Trans compression work.
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