Question about raw format

Discussion in 'Digital Photography' started by SolracSelbor, Apr 19, 2008.

  1. SolracSelbor macrumors 6502

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    Nov 26, 2007
    #1
    If you have a raw format such as .dng and it states that it is 8 bits is there a point to changing it to 16 bits in photoshop?

    EDIT: OOPS, i meant to say 12 bits
     
  2. Lovesong macrumors 65816

    Lovesong

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    Sep 15, 2006
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    Stuck beween a rock and a hard place
    #2
    That is a fairly short, and yet loaded question-

    Does it matter in terms of viewing? No. Your screen is likely not capable of producing more than an 8-bit image (unless you have a $4000 Eizo).

    Does it matter in terms of printing? Yes- your color space and color depth is essential for getting accurate and smooth gradients in your prints. While software will basically interpolate the bit depth- even my 5D is a 12 bit camera, and a new 1Ds is 14-bit, so selecting 16-bit conversion to tiffs allows me to go up to 16-bit. In your case, if you're printing, I would convert to 16-bit, as it would allow you more accurate editing. If you're just viewing the images, I wouldn't bother. You want to save your RAWs, regardless.
     
  3. infowarfare macrumors 6502

    #3
    From my understanding, it doesn't work that way.

    The benefit is when the camera outputs 16 or 12 bit images you can process them without reducing the colour depth.

    When you've got an 8 bit image and you convert it to 16 bits you haven't got any more colour information than you had before. You can't magically add bits that don't exist in the first place (same with digital audio, you can always convert down from 32 bits to 16, but not the other way around.)
     
  4. SolracSelbor thread starter macrumors 6502

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    Nov 26, 2007
    #4
    this is what I thought.

    Is there any camera that produces 16 bit raws?
     
  5. termina3 macrumors 65816

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    Jul 16, 2007
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    TX
    #5
    Some Hasselblads do. But are you looking to spend $20K++ on a camera?
     
  6. SolracSelbor thread starter macrumors 6502

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    Nov 26, 2007
    #6
    not really, I was just curios
     
  7. compuwar macrumors 601

    compuwar

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    Oct 5, 2006
    Location:
    Northern/Central VA
    #7
    Even cameras with 12 and 14-bit output work in 16-bit space in Photoshop. Large format scanning backs and some medium format backs generally go to 16-bits/color However, if you're not exposing as far to the right as possible, you're not using all your bits..

    http://www.luminous-landscape.com/tutorials/expose-right.shtml
     
  8. ChrisA macrumors G4

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    Jan 5, 2006
    Location:
    Redondo Beach, California
    #8
    Yes but you are not likely to have one. But many common consummer level cameras output 12 bits and a few will do 14. 12 or 14 bits of data will "fit" in a 16-bit file but not in an 8-bit file.

    If you data is 8-bits does it help to convert it to 16-bits? Maybe if you are going to do a LOT of post processing but then I doubt it. Reducing the color depth is mostly a one way function you can go down but doing so throws away some information that can't be recovered by going back up.

    There is just one very technical exception. It applies to both images and audio. If you add two sources, that is combine tracks or images you in theory gain a bit. The sum of two 8-bits numbers can have as many as 9 bits.
     
  9. compuwar macrumors 601

    compuwar

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    Oct 5, 2006
    Location:
    Northern/Central VA
    #9
    The cheapest BetterLight back is $6500, you can pop it on ~300-500 worth of view camera, making the total investment for 48-bits of digital of under $7,000.
     
  10. SolracSelbor thread starter macrumors 6502

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    Nov 26, 2007
    #10
    Does anyone know how to convert their RAW photo to a 16 bit TIF? Every time i convert a 12-bit RAW .DNG photo it converts it to an 8-bit TIF in CameraRaw. How do I change this?
     
  11. infowarfare macrumors 6502

    #11
    As I mentioned before, you can't because you can't convert up (since you can't magically add extra bits that don't exist) you can only convert down.
     
  12. SLC Flyfishing Suspended

    SLC Flyfishing

    Joined:
    Nov 19, 2007
    Location:
    Portland, OR
    #12
    CS2 or CS3?

    In lightroom there's just a dropdown menu when your go to export a file. Select tiff then you can select either 8 it or 16 bit. You want to select 16 bit since selecting 8 bit will shave some of your data away!

    SLC
     
  13. compuwar macrumors 601

    compuwar

    Joined:
    Oct 5, 2006
    Location:
    Northern/Central VA
    #13
    At the very bottom, between the "Save Image" and "Open Image" buttons is a line describing the file's color space, bit depth and resolution. Click on that and you'll get a dialog box with a drop-down for bit depth.
     

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