Demo Canon RAW vs jpeg benefits?

Discussion in 'Digital Photography' started by David Ellis, Oct 6, 2003.

  1. David Ellis

    David Ellis Guest

    With various Canon cameras (G1, G2, D60) I've attempted to design an
    experiment that would clearly show the benefits of using RAW format.
    I understand the theory -- getting a file of raw data as "seen" by the
    sensor without any camera-computer processing, thereby retaining all
    the processing options.

    I can't print larger than 8 1/2 x 11, using a Canon S800. Maybe such a
    demo requires 11x14 or larger.

    With each trial, using a wide variety of software, including many
    Photoshop actions posted by others, BreezeBrowser, etc., I have failed
    to demonstrate any significant difference between RAW and jpeg large
    fine.

    Could someone suggest a blow-by-blow demo of the RAW benefits over
    jpeg large fine? I'd like to follow the steps and see the contrast.
    (Now using a 10D.)

    --David
     
    David Ellis, Oct 6, 2003
    #1
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  2. Hi, David,

    Jay Maisel has an article in the current issue of Digital Photo Pro (Volume
    1, issue 1, get it while it's still extant), page 64. The master says,
    I've had 40x60-inch prints made from JPEGs, and the only people
    who have a problem with them are the ones who get two inches
    away from the print and say, "Aha! There are artifacts!"

    He says he doesn't shoot in RAW mode, only in JPEG fine. The last page of
    the magazine has an essay on just this topic: RAW v. JPEG. Answer: it
    depends.
     
    Phil Stripling, Oct 6, 2003
    #2
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  3. David Ellis

    Rafe B. Guest


    If you can't see the benefits of RAW, then don't bother with it.

    JPG will certainly give you more shots per CF card, and will
    be understood by more image viewing/printing apps.

    The benefit of RAW will show up with large prints, and has
    the added benefit of giving you more flexibility in processing
    the image, or (for example) tonal range control using layers
    and multiple "exposures" from the same image. If you don't
    need any of that, then don't bother with RAW.

    If on the other hand, you're an anal geek like the rest of us,
    and want to eke out every last bit of information from your
    digicam images, shoot with RAW and learn to use it.
    There are plenty of tutorials on the web; Canon's web site
    is a good place to start.


    rafe b.
    http://www.terrapinphoto.com
     
    Rafe B., Oct 6, 2003
    #3
  4. David Ellis

    Jim Townsend Guest

    David Ellis wrote:


    Are you trying to show RAW has better *resolution* than a large fine JPEG.
    (ie. it produces a sharper image). ?

    This may start some controversy, but (post processing advantages aside).. I'll
    be darned if I can see *any* visual difference between a fine JPEG and a TIFF
    file created from RAW.

    I've taken both, put them side by side and viewed them at 800% zoom.. I just
    can't see a difference in resolution.

    Of course, RAW does give you *many* big advantages in post processing. I do
    use those advantages when doing portraits. RAW is also great when used with a
    grey card when it's important for white balance to be correct. I put my 18%
    grey card in the scene and choose it as the white point.. The balance is
    always perfect.
     
    Jim Townsend, Oct 6, 2003
    #4
  5. David Ellis

    Savidge4 Guest

    Could someone suggest a blow-by-blow demo of the RAW benefits over
    If you are in general, a decent photog the difference is minor, if at all. the
    differences in quality appear when you have a shot you "have to have" that is
    either under or over exposed. Adjusting these conditions could demonstrate the
    advantages of RAW.
     
    Savidge4, Oct 6, 2003
    #5
  6. David Ellis

    Martin Brown Guest

    You just have to choose the right bit to look at. And enlarge it more.
    No need to print it out you should be able to see it when the image
    scale is sufficient to see individual pixels clearly on a screen
    display.
    The simplest test case that will almost reliably force visible JPEG
    artefacts is a sharp black power line diagonally against a pale blue
    sky. Choose the distance so that the line is only one or two pixels
    across in the image.

    On some cameras the JPEG artefacts will be largely disguised by the
    effects of gratuitous amounts of in camera unsharp masking / sharpening.

    Regards,
     
    Martin Brown, Oct 6, 2003
    #6
  7. David Ellis

    Mark B. Guest

    For me, the biggest advantage of raw is being able to correct the white
    balance, adjust the histogram, and add some sharpening at the time of
    conversion. That's pretty easy to demonstrate - go outside and shoot with
    the camera set on say, tungsten white balance. I'd much rather fix a raw
    image than a jpg. Even when WB is set properly, there are times I tweak the
    color a little cooler or warmer.

    Mark
     
    Mark B., Oct 6, 2003
    #7
  8. David Ellis

    Rafe B. Guest


    What exactly does being a decent photog have to do with it?

    The issue is exposure lattitude -- and it is limited on most
    digital imaging devices.


    rafe b.
    http://www.terrapinphoto.com
     
    Rafe B., Oct 6, 2003
    #8
  9. David Ellis

    David Ellis Guest

    Thanks for the tip, Jay. A good time to take my first look at Digital
    Photo Pro.
    --David
     
    David Ellis, Oct 6, 2003
    #9
  10. David Ellis

    David Ellis Guest

    "... using layers and multiple 'exposures' from the same image..." may
    be what I already do in jpeg by shooting multiple exposures of a
    contrasty scene to obtain a shot exposed for highlights and one
    exposed for shadows. I then "blend" these in Photoshop to achieve what
    film photographers call "compression." The result is detail in both
    shadow and highlight. The 11-stop scene perceived by the human eye is
    compressed into the five-to-seven stops the digital system can
    reproduce.

    Are you suggesting there is an 11-stop range in a RAW file that can be
    accessed by appropriate techniques?

    <snip>

    --David
     
    David Ellis, Oct 6, 2003
    #10
  11. David Ellis

    David Ellis Guest

    No. I don't recall seeing a claim that RAW provides higher resolution
    than jpeg.
    I shoot everything in daylight balance, even incandescent, and make
    corrections in the image editor. I've only recently run across some
    images where applying white balance in the image editor wouldn't yield
    the desired result without going to great lengths.

    Are you saying you can get white-balance results in raw that you could
    not get in jpeg? If so, any chance you could post an example with a
    blow-by-blow explanation of how you did it?

    --David
     
    David Ellis, Oct 6, 2003
    #11
  12. David Ellis

    Savidge4 Guest

    I am not so sure "limited" would be the correct term, but "smaller" may be.
    meaning that there is a greater risk of not getting it correct, and in turn
    needing correction after that fact.

    With the canon line in particular there is a pattern in this. Overall dark
    shots tend to produce shots that are underexposed and shots that are well lit
    tend to produce shots that are blown out. This is becomiong a basic "given" in
    digital photography.

    when I read posts here with people making adjustments of 2 stops, I have to
    wonder. Thats 50% of the total exposure latitude. Thats like printing an 11
    x 17 image on 8.5 x 11 paper and saying "what happened, where is the rest of
    the image?"

    So again i say "if you are a decent photog" you really wont have to make 2 stop
    adjustments in exposure, you will have your white balance set correctly, and
    then the need for RAW is not so important.
     
    Savidge4, Oct 6, 2003
    #12
  13. David Ellis

    Mick Ruthven Guest

    I don't know exactly what the writer meant, but I routinely shoot RAW with
    my G3 and convert with BreezeBrowser. At the convert window, clicking on a
    neutral-color portion of the image automatically sets the proper white
    balance. Or you can select "daylight", "tungsten", etc., white balance at
    that time instead of having to set the camera correctly when shooting.
     
    Mick Ruthven, Oct 6, 2003
    #13
  14. David Ellis

    Mick Ruthven Guest

    Forgot to mention that with BreezeBrowser you can do the
    "click-on-neutral-color-area" thing and automatically apply that color
    balance to all the images in that batch for conversion. That's handy in a
    lot of situations, but really good for shooting through tinted glass or
    plexiglass. For shooting from a small aircraft with tinted windows I shoot
    one image of a gray card held in outside in the sun, camera inside shooting
    through the tinted window. And shoot all photos in that flight with Daylight
    (or whatever) WB. Then in BB I set the white balance for the gray-card image
    by clicking on the gray card and apply that WB to all the photos taken
    through the windows during that flight.
     
    Mick Ruthven, Oct 6, 2003
    #14
  15. David Ellis

    SD Guest

    Well then I would say shoot JPGs, convert to TIFF or BMP or some other
    non-lossy format for postprocessing. Is there any disadvatage to that?
     
    SD, Oct 6, 2003
    #15
  16. David Ellis

    SD Guest

    Not noticable on my dimage f100 and for better cameras it should be even
    less.. I tried clicking plain blue sky with only the powerlines. In fact
    ive never noticed any artefacts looking at 4MP images with a lot of zoom..
     
    SD, Oct 6, 2003
    #16
  17. David Ellis

    Seymour Guest

    What exactly is a neutral color?
     
    Seymour, Oct 7, 2003
    #17
  18. David Ellis

    Jim Townsend Guest

    No disadvantage.

    Since you're not recompressing and saving the JPEG again, it will be saved
    lossless as a TIFF. The only JPEG loss in the file will have been from the
    original conversion within the camera.

    (The filesize will be a heck of a lot bigger though).
     
    Jim Townsend, Oct 7, 2003
    #18
  19. David Ellis

    Jim Townsend Guest

    I think this ability to *precisely* adjust white balance under any condition is
    one of the major advantages of shooting RAW.

    I sometimes carry a grey card and include a piece of it in the corner of a
    photo. I choose it as white point, then crop it out in the final processing
    stage.
     
    Jim Townsend, Oct 7, 2003
    #19
  20. David Ellis

    David Ellis Guest

    I must have one of those gratuitous cameras. :=)

    I've photographed the power line against blue sky in raw and jpeg,
    processed the former in BreezeBrower, using default settings except
    16bit tiff. With the tiff and the jpeg side by side in Photoshop,
    zoomed to 1600%, I can't see any difference between the two.
    (Using a Canon 10D with Canon f2.8L lens.)
    --David
     
    David Ellis, Oct 7, 2003
    #20
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