Tiff vs Jpeg

Discussion in 'Digital SLR' started by Monty, Oct 2, 2005.

  1. Monty

    Monty Guest

    Can some one please tell me if there is any advantage converting RAW to tiff
    or RAW to jpeg. Any quality difference.

    Regards To all

    Monty
     
    Monty, Oct 2, 2005
    #1
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  2. Monty

    nv Guest

    In
    None, if all you do is look at your images on a monitor. It's the equivalent
    of looking at analogue negatives, as RAW files are the digital negative
    equivalent.
    Perhaps you might want to read a short 4-page pdf primer on this subject
    written by Bruce Fraser?

    http://www.adobe.com/products/photoshop/pdfs/understanding_digitalrawcapture.pdf

    hth

    Kind regards
    Nigel
     
    nv, Oct 2, 2005
    #2
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  3. Monty

    Monty Guest

    Thanks for the info Nigel.


    Regards

    Monty

     
    Monty, Oct 2, 2005
    #3
  4. Converting RAW to TIFF won't change the quality, but depending
    on the RAW format (i.e., which camera model) will have a more or
    less significant change in file size, requiring a much larger TIFF file
    to hold the same data as a RAW file.

    Converting to JPEG will lose significant data in the image. The
    effect that has varies though, because if you don't try to change
    things like the color balance or brightness and contrast, and if you
    view the image on a typical monitor, the process of viewing itself
    discards just about exactly the same data and you won't see much
    difference between formats.

    If you edit the image though, the JPEG version doesn't have all
    of the original data and can't produce the same results that
    editing a RAW file would. Typical results, for example, would
    be posterization of areas on the JPEG file that can be correctly
    adjusted with a RAW file. The JPEG might have fewer than 75
    brightness levels per f/stop range, while a RAW file may have up
    to 2048 levels (for example in the highlights). Adding a little
    brightness to a RAW format image can retain detail, while doing
    the same to a JPEG will almost certainly lose detail.
     
    Floyd Davidson, Oct 2, 2005
    #4
  5. Monty

    dylan Guest

    Generally speaking for simply viewing or printing to a reasonable size then
    there's not much difference, but if you plan to manipulate the images, ie
    sharpening, then you are best keeping as much information in the image as
    possible, and minimising artefacts, until you are ready for the completed
    image.

    TIFF will store more information than a compressed JPEG, but the
    disadvantage is memory space needed to store the images.
    You could compromise by setting the JPEG to minimum compression and seeing
    if that's good enough for you.
     
    dylan, Oct 2, 2005
    #5
  6. Monty

    JMW Guest

    If you plan to do any advanced post-processing, I believe that TIFF will
    allow you to work with transparent sections, while jpeg will not.

    Jan
     
    JMW, Oct 2, 2005
    #6
  7. Monty

    Bill Guest

    Actually there is a difference, especially on a monitor if the image
    size is retained. Detail can be lost with JPEG compression, while TIFF
    is a lossless compression.

    However, the file size advantage of JPEG is obvious, and if you're
    converting the RAW file for display to others, JPEG is the way to go.
    You don't want to force users to download massive 15-20meg TIFF files
    for viewing on the net.

    Of course, it should go without saying that the original RAW file should
    be kept as a "digital negative" in the event you wish to change the
    viewed file or if you want to print a photo.
     
    Bill, Oct 2, 2005
    #7
  8. Before transmitting an image to the lab to be printed, I save it as a
    TIFF file. The quality of the prints seems to be much better,
    especially with large sizes.
     
    Randall Ainsworth, Oct 2, 2005
    #8
  9. Monty

    DoN. Nichols Guest

    [ ... ]
    With the exception of what happens if you intend to zoom into
    fine detail on your monitor. Then a TIFF is far better than a JPEG, and
    a RAW keeps more range of brightness, allowing you to recover more
    detail from shadows if you need to do so.

    Where JPEG is really terrible is on a two color (e.g. B&W) photo
    or scan of a line drawing with lots of fine detail (such as an exploded
    parts diagram for some piece of equipment which you intend to attempt to
    repair. JPEGs of that can lose both fine detail form the drawing
    itself, and legibility in the tiny text which can accompany the drawing.

    The typical TIFF has no compression, so it is painfully larger
    than a JPEG, but compression can work with a TIFF, which makes the pain
    a lot less.

    Enjoy,
    DoN.
     
    DoN. Nichols, Oct 3, 2005
    #9
  10. If you want to work further on the converted image (in PhotoShop etc.), it
    is better to convert initially to TIFF - 16 bit. Only when you have
    completely finished (including any re-size and sharpening) should you save
    as 8 bit JPEG to get the file size down.

    Mike Bernstein
     
    Mike Bernstein, Oct 3, 2005
    #10
  11. Monty

    JPS Guest

    In message <>,
    RAW conversion is still in the dark ages, as well, IMO. You may have
    opportunities to make better images from them in the future. The
    shadows are basically trashed by current RAW converters.
    --
     
    JPS, Oct 3, 2005
    #11
  12. Eh?
     
    Randall Ainsworth, Oct 4, 2005
    #12
  13. Monty

    JPS Guest

    In message <031020051858444871%>,
    Yep. The deepest shadows have half of their pixels clipped.

    And while it is not directly the fault of the converters, most fail to
    account for the banding offsets in the readout.
    --
     
    JPS, Oct 5, 2005
    #13
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