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Future Proofing RAW files

Discussion in 'General Equipment Chat & Advice' started by IanG1957, Dec 10, 2018.

  1. peterba

    peterba Well-Known Member

    Pete, I have wondered this, too - I also have a suspicion that it's nothing more than a commercial racket.

    I have version 0.19.2 of the freeware Raw converter, UFRaw (release date: March 2013) which will happily open files from current cameras. However, when attempting to open the same files with other - more recent - software programs (but not freeware), a message is displayed to the effect that the "File is not supported by this version".

    Hmmmmmmmm........I smell a rat (or possibly a cosy little cartel). :(
  2. Benchista

    Benchista Which Tyler

    The WHOLE point about RAW is that you're extracting the maximum possible information, which inevitably means what the file contains will vary from generation to generation as new features get added. Strikes me as totally counter to the point of RAW to NOT have an updated file format every time that takes full advantage of that, and certainly I wouldn't buy a camera which couldn't take advantage of that because it imposed a standardised unchanging RAW file format - it seems absurd, a real case of the tail wagging the dog.
    Besides, I've been using DSLRs (and thus RAW files) for 15 years now, and I don't have a problem with any of the RAW file formats in at least 2 different software packages. Nor, in fact, from an even older model I bought which was just about the first enthusiast DSLR on the market. Worth keeping a copy of Adobe DNG converter just in case, of course, but otherwise, I don't see any evidence that it's actually an issue for any extant digital camera manufacturer - might be a problem for my Kodak DSLR, though, going forwards, if an OS upgrade stops my Kodak software working, and I would be worried if I had a Contax, Minolta or Samsung.
  3. PeteRob

    PeteRob Well-Known Member

    It is largely semantic. The point of a file format is that it is a standard for encoding necessary information. The information may change in time and indeed it can't be foreseen what that information might be, but the format of the file shouldn't change even if the content does. Further the format is self describing so that a program can deconstruct the file.

    The only thing I can think of that would need adaption is if the manufacturer adds a camera specific feature not described in the file but tied to, for example, the model name. This is what would need a new software issue. That is not a file format issue as it lies outwith the format.
  4. daft_biker

    daft_biker Action Man!

    Also DNG can be updated so it would be easy to tamper with shots. Proper RAW files track changes in a separate file so the integrity of the original is maintained.
  5. IanG1957

    IanG1957 Well-Known Member

    This is only true if you decide not to let LR store the metadata (for the DNG files) - if you do use LR to store the data, the process is the same as treating a RAW file. (And in fact becomes slightly faster as the data file sizes are less important)

    Or so I'm told…

    There's an interesting article over on Peta-Pixel

  6. Benchista

    Benchista Which Tyler

    So how, for example, would DNG cope with Canon's Dual Pixel Focus information? And the answer is - it couldn't. It's a file format issue alright.
  7. PeteRob

    PeteRob Well-Known Member

    I thought Canon had a new raw format for that, CR3 ?
  8. Benchista

    Benchista Which Tyler

    Yes, they had to update the file format... ;)

    This is my very point. As certain things are introduced, the file format needs to change to allow for it. If you stick with DNG, that's just not possible, and thus it restricts what advances can be included in the camera. Tail wagging the dog.
  9. PeteRob

    PeteRob Well-Known Member

    It depends on the processor. Canon DPP writes edit instructions to the file (image data is not changed). LR to either the catalogue or to a separate file, On1 to a database or to a separate file. Last time I used Capture One it wrote to a separate file.
  10. PeteRob

    PeteRob Well-Known Member

    OK I lose that one if you consider CR3 to be an update of CR2 rather than an entirely new format. In my eyes the point of a format is that it describes how the information inside the file is written. I agree entirely there can become a point that the format is inadequate and a new one is needed.
  11. Benchista

    Benchista Which Tyler

    Yes, that's the only point I'm trying to make - file formats will change, and be replaced. But DNG is DNG. Sure, it can hold different data, but once you need to include new data classes, it can't cope, so it rather hamstrings the camera developers.
  12. PeteRob

    PeteRob Well-Known Member

    Yes. We were at cross purposes. A format is a container. A DNG is a DNG, a CR2 is a CR2 and a RAF is a RAF etc, sooner or later you need a new container.
    Benchista likes this.
  13. daft_biker

    daft_biker Action Man!

    DNGs can be altered though. I was thinking of things like natural history competitions where sometimes they ask for RAW files to prove the content has not been changed. Perhaps it is relevant to crime scene photography too?
  14. Terrywoodenpic

    Terrywoodenpic Well-Known Member

    An 8 bit tiff file, saved with LWZ compression, is about the same size as the original raw file.
    This is how I save most of my images. as I am reasonably confident that I will never revisit a raw file after a few weeks anyway.

    I actually hold most of the raws, dumped into a hold file, for some six months. as I find I do sometime want to work on them again in the first few days or weeks. There after they are binned. so for me Dumping is a two stage process.
  15. IanG1957

    IanG1957 Well-Known Member

    I'd be the first to say that it's rare that I go back to revisit an old file, but it can happen.

    I do a lot of work with theatrical companies and it's not unknown that they come back to me a year after a performance and ask for images I made, based on an online album of the performance - at this point I generally go back to the original files, if only to give a series of images before and after the chosen one - which means I process files I hadn't touched before. I sometimes see them in a new light (excusing the pun) so having a RAW file is a huge advantage for me as I can apply the same 'corrections' to the whole series (for coherencies sake...)

    I have nearly 5Tb of RAW data, so no, I don't get rid of anything - and yes, I know I should!

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