NEF vs JPEG fine, large on D70 - benefits?

Discussion in 'Digital Cameras' started by AK, Nov 26, 2004.

  1. AK

    AK Guest

    I have been running some (admittedly simple) tests with my D70, trying to
    see if there is any significant difference visible in pictures taken with
    the NEF vs. JPEG, fine, large setting (both are 300 x 2008 pixels - the NEF
    is stored in a 5,4MB file, the JPEG in a +/- 2.4MB file). Obviously, the
    JPEG has a compressed version of the picture.

    In practice, the difference are so small that I can barely see them -
    literally at the level of one or two pixels brighter or darker in an area-
    and it may even be a matter of taste which is "better". (I use PS elements,
    and transfer the images from the camera to my computer using
    PictureProject). What really surprised me was that the much more compressed
    JPEG that the D70 provides to allow you to view images in IE and to store
    EXIF information, even though only about 750KB vs. 2.4MB for the fine, large
    JPEG, was also barely distinguishable form the other formats!!

    So - is the difference really simply that the NEF format is lossless and
    allows you, if you wish, to adjust exposure and white balance when importing
    to PS, and keep saving in lossless format? (I understand that repeated
    saving images in JPEG format loses information, and, of course, the JPEG
    could always be saved in TIF or PSD format).

    And, importantly, if you blow these up to a large print size, such as 13" x
    19", is there likely to be any quality difference visible between the NEF
    and JPEG image, assume both go through the same PS processing steps, or are
    not postprocessed in PS at all?

    I put up a couple of screen shots showing the comparisons at
    http://www.photo.net/photodb/photo?photo_id=2911793&size=lg and
    http://www.photo.net/photodb/photo?photo_id=2911790&size=lg . The images
    have had no PS post processing (no levels, sharpening etc. - just as they
    were transferred from the camera to PS. And, of course, you're viewing them
    at the resolution your screen can give of a screen shot off my screen, but
    they seem reasonably representative of what I view in PS.

    Alan
     
    AK, Nov 26, 2004
    #1
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  2. AK

    Aerticeus Guest

    In general there is a great deal of difference between RAW and JPEG

    If you can't notice it, don't worry or be anxious about it and save with the
    format that meets and addresses your needs

    Aerticeus
     
    Aerticeus, Nov 26, 2004
    #2
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  3. AK

    AK Guest

    Oops - should say 3000 x 2008, not 300 x 2008
     
    AK, Nov 26, 2004
    #3
  4. AK

    AK Guest

    Well, I guess my question is - what is the visible difference? Are there any
    examples out there of significant differences visible?

    E.g., if I printed the same picture a large blow-up, would I notice a
    difference between the image captured as a NEF vs. the image captured as a
    JPEG (on the D70) - same number of pixels in each case - just that the D70
    has compressed and possibly tweaked the image data using an in-camera
    algorithm in the JPEG format?
     
    AK, Nov 26, 2004
    #4
  5. AK

    Aerticeus Guest

    S'OK AK - we all do it from time to time but I think everyone knows what you
    meant

    You've really answered the question you asked

    If you are happy and pleased with in camera processing - well, JPEG is fine

    If you want to tweak images on PC rather than rely on incamera processing =
    go RAW

    If you do go RAW it may be wise to invest in a dual processor 'pooter

    Both MAC and PC variants show a marked performance while image processing
    using duals (or quad) pumped cpu units (IMHO)

    So, there you go. No absolute best answer as it depends upon what you want
    to do with the kit and the files it produces :)

    Aerticeus
     
    Aerticeus, Nov 26, 2004
    #5
  6. AK

    Wright Guest

    And, importantly, if you blow these up to a large print size, such as 13"You are showing some results here that are much closer than what I, or many
    others, might have imagined! However, perhaps one thing you are forgetting
    is what if your original exposure needed work to rescue? Suppose, for
    example, that it was badly under exposed. It would be much easier to pull
    some detail out of the raw image than out of the JPEG.
    Chuck
     
    Wright, Nov 27, 2004
    #6
  7. AK

    Aerticeus Guest

    I think you have answered the question yourself Rita

    6 seconds for a RAW file is quite good, less than 1 second to start
    applications is also very good

    The extra umph of a dual cpu setup supported by fast SCSI and I daresay a
    sizeable chunk of RAM helps

    However, to go to the original message, there is a lot of functionality
    built into cameras and almost, it seems, a guilt factor about not using
    parts of that functionality because the user - well to put it bluntly - sees
    no difference.

    It really is OK to use the camera in the best way for an individual user
    without using all the bells and whistles if the end user does not want to

    It really is OK

    For example, how many 7-seater vehicles are there that are fully occupied
    100% of driving time with 7 people? (at a guess I'd estimate zero, zilch,
    nada)

    Same with cameras - because the feature is there does not mean it has to be
    used 100% of the time

    Aerticeus
     
    Aerticeus, Nov 27, 2004
    #7
  8. AK

    AK Guest

    Chuck:

    You definitely have a good point there about dealing with poor exposed
    shots - even though the D70's metering is superb, it's not always what you
    want or expect, specially if you forget to adapt it to the special
    circumstances of a difficult shot - e.g., using full matrix metering when
    spot would be better, or changing the white balance.

    One of the reasons for my interest is simply that one can fit so many more
    JPEG images on a storage card or drive than NEF, which is useful when
    traveling, for example, or taking sports shots (also, with the JPEGs, the
    camera keeps up with continuous mode shooting better since it stores 9
    actual pictures in its buffer (in NEF+Basic, it stores only 4 - one for the
    NEF and one for the same basic JPEG) and empties the buffer faster, so you
    are ready to shoot another sequence sooner. Since the difference seems so
    negligible, I may stay with JPEGs except for shots where I really want to be
    able to fine tune the exposure.

    The other reasons for going with JPEGs are that storing the NEFs chews up a
    lot of disk space quite fast, and bringing them into the computer and then
    uploading to PS is much slower, as Rita pointed out elsewhere in this
    thread, though that bothers me less as I am not a professional concerned
    with the speed of my workflow.

    Thanks

    Alan
     
    AK, Nov 27, 2004
    #8
  9. AK

    LarryLOOK Guest

    There's enormous debate about jpeg vs nef on dpreview d70 forum. Nef lovers
    seem to point to 16bit color of nefs, but I don't think my eyes are that
    good. And apparantly nefs are not full 16 bit color. Also, sinces dslr's
    get wb setting (when camera is set on auto wb) on the basis of less
    information than a point and shoot (or so I've been told) - they can get the
    WB wrong. It's easier fixing wb and exposure in processing with nef than
    jpeg. That being said I still don't know what's right for me and go back
    and forth. It's disheartening when you get a ton of average photos in
    nef/basic jpeg. You feel your wasting HD space for no reason. But maybe
    for that winner shot, where the camera chose the wrong wb for you, you'd
    wish you'd taken it with nef, no? For me, with 98% of shots, when I view
    them, I wish I had just taken them with fine jpeg setting.

    There's an art to opening nef's with ps elements, and I'm curious what
    people here are doing with the photo's when they open them up in elements.
    What are the most common options you play with?
     
    LarryLOOK, Nov 27, 2004
    #9
  10. AK

    Roger Lake Guest

    Why would you use Auto WB? You should always
    set the WB unless you're using a mixed light source,
    and then you can shoot a card.
     
    Roger Lake, Nov 27, 2004
    #10
  11. AK

    Roger Lake Guest

    By "pixels" do you mean "incremental levels" or
    something like that? Are you actually examining
    individual pixels on a display screen? Brightness
    is not a very good indicator of JPEG quality.
    Look for artifacting or blurred edges.
    The first use of JPEG also causes loss. Saving a JPEG
    from the camera as a TIF still loses information from
    the camera's own JPG conversion of the raw data.

    Why not use both? Shoot in NEF, transfer to your
    hard drive and archive as NEF. All your work can
    be done, if you like, on JPEG, TIF, PSD, BMP or
    any format you wish to play with. Just use a batch
    converter like IrfanView or Bibble to create working
    images from the archived NEFs as often as you like.

    As for disk and card space -- prices have come down
    on cards, and disks these days are enormous. If you
    dump the losers periodically, you won't have a storage
    problem. I have a lot of cards and use external FireWire
    drives for storage. If you don't, then use JPG.

    As for the buffer issue, there I agree. If you're shooting
    sports shots and need quick turnaround and can stand
    the use of JPEGs, then by all means do it.

    The perceived quality difference can be quite small.
    Even pro labs will tell you they don't see much difference
    in shots they print from JPG. But I like having the raw
    camera output to work with. There are times when that
    small difference makes ALL the difference in workflow
    output.
     
    Roger Lake, Nov 27, 2004
    #11
  12. AK

    Aerticeus Guest

    Hi Roger

    whoa - slow down, everyone doesn't have the same range of experience and may
    be quite new to JPEG - RAW

    6 months ago I didn't know that JPEGs had different levels of compression
    now I realise that

    To go back to the automobile example I gave earlier - it is a function there
    to be used No law against using it - No law about having to use it

    Aerticeus
     
    Aerticeus, Nov 27, 2004
    #12
  13. AK

    AK Guest

    Just to add fuel to the flames .... without ignoring the issue of being able
    to manipulate the NEF file better in the event of exposure problems.

    I've added another test shot D70 NEF vs. JPEG. The JPEG here is the "Basic"
    JPEG, file size 749 KB, that the D70 stores along with the NEF file (so you
    can easily view an image in Windows Explorer). This is highly compressed vs.
    the 5 MB NEF file. Images at 72 pixels/inch in PS Elements, set to "View
    Actual Pixels" . See
    http://www.photo.net/photodb/photo?photo_id=2914965&size=lg

    Image is of my daughter's right eye, using a Sigma 70-300 APO, the D70
    on-camera flash, macro mode. USM of 100-20-1 applied, no other changes,
    which actually seems to slightly emphasize the quality difference in favor
    of the NEF. You can easily see, in both images, the rim of her contact lens,
    and you can see that the NEF is marginally sharper (look, e.g., at the flash
    highlight in the center of the pupil, and some of the eyelashes). But the
    difference is remarkably small, even at this level of compression, and if I
    had shot it as a "large, fine" JPEG, would have been impossible to detect, I
    believe. (The D70's "large/fine" setting creates JPEGs of 2 MB i.e.,
    compressed much less than the "Basic" image I've shown here.)
     
    AK, Nov 27, 2004
    #13
  14. AK

    Roger Lake Guest

    Comparing un-manipulated NEF images to JPEGs
    is, to me, a pointless exercise. The purpose of NEF
    or any raw file is to provide a basis for manipulation.

    Some people don't want to do that, and choose
    camera JPG, and I don't have a problem with that.
    To each his or her own.

    But the comparison, in my estimation, should be
    made between a JPG from the camera or perhaps
    manipulated, and a NEF file that has gone through
    a standard WB-Levels-Curves-Sharpness treatment,
    at least.
     
    Roger Lake, Nov 28, 2004
    #14
  15. AK

    Tom Scales Guest

    Good grief why? The D70 Auto WB is outstanding. I very rarely have to set
    it specifically.

    Tom
     
    Tom Scales, Nov 28, 2004
    #15
  16. AK

    Hunt Guest

    The best example(s) that you could find would be to shoot the same scene in
    both modes, bring into your image program and then use the Magnifying Glass
    Tool to take them up many times. compare the images. If you don't find any
    problems with the JPG, then use it. If you find artifacts (no offense Arty),
    then you need to decide if they are objectionable, and is the RAW method worth
    the HDD real estate. As Arty stated, it's really up to you.

    Hunt
     
    Hunt, Nov 28, 2004
    #16
  17. AK

    Cynicor Guest

    I just screwed up some pix tonight. I had the camera set to custom white
    balance at a hockey rink, and was shooting NEF+JPG. Then I took it inside to
    a post-game party for the team and swapped it over to JPG only, but took a
    bunch of pix before remembering to reset the white balance. Everyone looks
    like they need to be treated for exposure.
     
    Cynicor, Nov 28, 2004
    #17
  18. AK wrote:
    []
    A most interesting comparison! My own tests on both a Nikon 990 and 5700
    of the different JPEG levels have lead me to use Basic for most of my
    work. Of course, it also depends on your exact viewing conditions as to
    what level is required.

    Where I have recently found the Basic level to be not quite good enough is
    in areas of slightly-saturated colour - and slate roof that is just
    off-grey, or a very pale blue sky (not an intense blue), and perhaps areas
    of grass. There can be a slight "muddiness" in these areas - the colour
    is not well-defined and the pixels sort of blur into each other, and
    perhaps there is a blockiness of the JPEG 8 x 8 or 16 x 16 cell size.

    You can't see this by looking at the full image on a CRT display, though,
    you need to zoom in to a level equivalent to looking at a print with a
    magnifying glass. So depending on your use of the pictures, the better
    quality of Fine versus Basic JPEG, or NEF versus JPEG /may/ be worth the
    extra file size or processing time.

    Cheers,
    David
     
    David J Taylor, Nov 28, 2004
    #18
  19. AK

    AK Guest

    To your point, I found that taking a picture that included a very vividly
    blue sky, the NEF rendered it "properly" (i.e., the image seemed to match
    the actual color I perceived in the sky) while the Basic was a rather murky
    grey blue.

    I have also begun to consider whether the software used to view and process
    the images isn't a major component - since each software package has its own
    way, I imagine, of reading, decompressing and displaying a JPEG, NEF (or
    RAW) file, that could introduce variations. (I refer only to perceived
    "sharpness" or "quality" - of course, the entire postprocessing workflow,
    down to and including the printer and driver etc. will affect the final
    print).


     
    AK, Nov 28, 2004
    #19
  20. Well, in that sense the NEF doesn't contain any rendering at all - just
    the raw sensor values - so yes, the rendering will be dependant on the
    software used to convert from sensor values to RGB.

    Sensor to RGB conversion will depend either on the camera firmware (for
    the JPEG or TIFF images from the camera) or on the program used to read
    the file (for the NEF file to RGB conversion). There isn't one "right"
    result, and different methods will produce different results that
    different viewers may find differently pleasing. "JPEG from the camera"
    users have none of these problems to worry about!

    RGB converted to JPEG and then back to RGB for processing will have small
    errors in each of the RGB components. How RGB is encoded to JPEG depends
    on the quality level set (which the user can control) plus some data
    tables and colour sampling methods which will be chosen by the
    manufacturer. It is an art rather than a science to make the best choices
    for a particular camera. Decoding JPEG to RGB should be a completely
    deterministic process, though - i.e. all software should do it in exactly
    the same way as it is mathematically defined.

    Cheers,
    David
     
    David J Taylor, Nov 28, 2004
    #20
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