RAW vs JPEGs - Does RAW show more detail?

Discussion in 'Digital Photography' started by Tim, Jun 24, 2006.

  1. Tim

    Tim Guest

    I'm trying to assess the image quality of several cameras and have been
    downloading iso100 full-size sample images from dpreview. Are these
    images examples of the highest detail that I would receive from the
    cameras or would RAW images show much more detail? So far, I haven't
    been impressed with the digital SLRs in my price range but was wondering
    if their RAW images would provide higher detail.

    Tim, Jun 24, 2006
    1. Advertisements

  2. Tim

    SteveB Guest

    I saw some tests of RAW vs. JPG under difficult high contrast conditions and
    where the JPGs had blown out the highlights there was still detail in the
    RAW files. A wider dynamic range basically.
    SteveB, Jun 24, 2006
    1. Advertisements

  3. Tim

    cjcampbell Guest

    Raw images preserve more information in the highlights and shadows.
    Bringing up the shadows in a raw image will frequently show details
    that are missing in a JPEG.

    However, a raw image will not be sharper or show details that simply
    are not there. If a line looks fuzzy in JPEG, it is because it is fuzzy
    in the raw image. If you are not impressed, it is because the images
    you are looking at are tiny areas of the whole image blown up large. In
    real life, you probably not get anywhere near the detail that the
    DPReview pictures have. Still, it is probably more detail than you
    would get in 35mm film, which does not have the dynamic range or number
    of colors that digital has. Whether 35mm film is sharper or less
    grainy, of course, depends on the film and the ISO of the digital
    image. In general, digital now produces more detailed pictures than
    film, but film still has more 'shoulder,' that is, it continues to
    preserve more details in blown highlights and deep shadows than even a
    raw image.
    cjcampbell, Jun 24, 2006
  4. Tim

    My View Guest

    That's right. RAW does give more detail in the highlights as that is where
    most of the information is stored (ie 2048 levels out of 4096 are in the
    brightest section (first stop) of the dynamic range.
    Also that is why you should expose to the right in the histogram when
    shooting RAW.
    Best to read this article for better explanation http://tinyurl.com/2hebo
    I've seen some amazing detail come out of what appeared to be an overexposed
    RAW image.
    My View, Jun 24, 2006
  5. : I'm trying to assess the image quality of several cameras and have been
    : downloading iso100 full-size sample images from dpreview. Are these
    : images examples of the highest detail that I would receive from the
    : cameras or would RAW images show much more detail? So far, I haven't
    : been impressed with the digital SLRs in my price range but was wondering
    : if their RAW images would provide higher detail.

    : Thanks.

    You have already heard about the level of information that is in the
    extreems of lighting so I won't go into that. The amount of detail is
    largely dependent on the size of the light sensitive elements with
    relation to the whole. If an image is made up of only four light sensitive
    elements, the smallest discrete element that can be resolved will be 1/4
    of the whole. If the same image is made up of 1 million sensors, the
    smallest element resolvable will be 1 millionth of the whole. So a 1 mp
    raw image will have the same minimum resolvable element as a 1 mp jpg
    image. Of course the subsequent jpg compression and or any changes in
    color pallet would impact this resolution. If the color pallet of the Raw
    file from the camera is 16 bit per pixel and the jpg conversion compresses
    this to 8 bit per pixel, the subtle variations within an image may be lost
    or muddied.

    But to compare this to film the pixel resolution of a digital camera can
    directly relate to film grain. But with film the grain size was a function
    of the film speed (to an extent). With digital this isn't a direct
    relationship. A 3 mp sensor and an 8 mp sensor can both give the same ISO.
    Even tho the 8 mp sensor will capture much finer detail (in relation to
    the whole image) than the 3.


    Randy Berbaum
    Champaign, IL
    Randy Berbaum, Jun 24, 2006
  6. Tim

    minnesotti Guest

    I never had or used a dSLR but read a lot about it :) .

    dSLR have a large CCD chip (say, 20 mm x 30 mm) as compared to a
    point-n-shoot (at most, 6 mm x 8 mm). This means the dSLR can have a
    small deapth of field (DOF). This means that you can have
    "traditionally-looking" (as in 35 mm film) portraits with blur of
    background. (No background blur for small-sized CCD sensors.)

    The other advantage of having a large CCD chip is that pixels can be
    large. This means they provide less of noise. If you shoot your picture
    in the conditions which are less than perfect (e.g. dimly-lit room),
    then you will have less noise and thus more of "detail". If you shoot a
    small-sensor camera with the same high speed in a dim room, you will
    get lots of noise. When the camera process theimage and doe noise
    reduction, the details go.

    A speedier optics of dSLR provides more light to CCD chip. Thus, less
    noise (=more detail) when shooting at high ISO.

    If you process your RAW image into a JPEG by your computer (and the
    processing is not done by an on-board camera processor), you have more
    powerful software at your fingertips. With a certain degree of skill,
    you are able to get more detail.

    Now, I presume you would like to hear from the people who actually used
    dSLR about what levels of detail and noise they see in their real
    world-shot pictures, as compared to those made with smaller-sensor

    minnesotti, Jun 24, 2006
  7. Tim

    Bill Guest

    The samples will give you a guideline and close approximation of what
    you can expect, but not always completely accurate.

    For instance, my lowly Canon Rebel XT seems to be better at doing
    "in-camera" conversion to JPG files than my friend's Nikon D70s.
    However, the Nikon seems to be capable of finer detail and resolution on
    a pixel to pixel scale (due to pixel size?). The Canon has a sensor with
    more pixels, so overall it captures more detail.

    If we take identical shots with the Nikon though, and convert the D70s
    RAW file in software, it contains substantially more detail and
    resolution than the "in-camera" JPG.

    The Nikon D70s seems to losing detail in the JPG conversion in an effort
    to keep file sizes lower. For 4x6 snapshots, that works great and you
    wouldn't notice the difference compared to Nikon or Canon photos of
    similar shots. But if you intend to enlarge or show the images on a
    computer, the D70s RAW images have a LOT more fine detail and it's the
    preferred storage format.

    In the end, if you shoot RAW with any camera, you should have the best
    it can offer.
    You will always get higher detail, highlights, resolution, etc. with a
    RAW file because it hasn't been converted to JPG, which is a lossy file
    Bill, Jun 24, 2006
  8. Tim

    Lobby Dosser Guest

    Why not expose correctly to begin with? This is a serious question, not a
    snide remark.
    Lobby Dosser, Jun 24, 2006
  9. Tim

    ben brugman Guest

    Because there is no correct exposure. (This is not a snide remark :)

    With film there was a shoulder when exposing film. This meant that in
    places where the film was 'overexposed' there was still some difference
    in the exposure.

    Digital (CCD's) are far more lineair. So exposure goes to a certain point
    and beyond that you get overexposure. In those overexposed area's there
    is no difference in the exposure anymore. So for any important parts of the
    picture you should not cross that line. (Where with film the line was more

    With digital (CCD's) most information goes in the high end of the exposure.
    Allthough varying with different camera's there are a lot of digital value's
    for the high end exposure. For a 12 bit system there are over 2000 values
    in the highes level (1 stop) for the exposure.

    So if you do postprocessing with your digital picture, you should not cross
    the line for overexposure, but should use as much of the higher levels as
    possible. For high contrast scenes this will often be the correct exposure
    as wel. But for low contrast scenes, this can give an overexposed scene,
    but with more information to play around. It's (fairly) ease to correct this
    exposure digitally in postprocessing.
    So with digital camera's there can be a difference in capturing as much
    information as possible in a scene and capturing with the correct exposure.

    Because correct exposure is not totaly defined, you can choose for
    capturing as much information as possible and get the correct exposure
    on a pc.
    But if you are capable of making the correct exposure for sure, you can
    choose to make the correct exposure at the time of making the picture.
    If the exposure is correct you have enough information for the picture,
    but less information to play around with.

    So to capture as much information the advise is expose to the right, but
    NOT beyond. For low contrast scenes you probably have to reduce
    the exposure in postprocessing, this will give good results.
    (Making the mistake of underexposure, you have to postprocess and
    increase the exposure. This is not optimal and in some instances will
    result in worse pictures).

    with kind regards,
    ben brugman
    ben brugman, Jun 24, 2006
  10. "What appeared to be an overexposed RAW image", wasn't
    over exposed.

    It would have been more correctly exposed than the others it is
    being compared to!

    It's just that if someone shoots off 300 frames that all turn
    out looking right, and the exact same raw data to image format
    conversion makes the 301st image look over exposed, people will
    (incorrectly) tend to say it "appeared to be over exposed".

    In fact it wasn't, and the other 300 should be described as
    "appearing to be under exposed, and requiring special adjustment
    to compensate". ;-)
    Floyd L. Davidson, Jun 24, 2006
  11. Tim

    Alfred Molon Guest

    Also depends on the camera. JPEGs from the Sony R1 for example are
    processed very bad in-camera, so you need to shoot RAW to get the full
    Alfred Molon, Jun 24, 2006
  12. Even better with RAW images one can use Photoshop's HDR process to get
    a huge dynamic range just not possible with either film or JPEG.

    For more about HDR see.


    Additionally by using RAW and working in the ProPhoto color space one
    has a far larger color gamut to use in ones prints now that high end
    printers aren't 8bit limited.

    I can not think of any reason one would shot JPEG unless one just
    didn't care about the quality of their work.


    "One, two, and the Depot RAR-O, I will buy you a sweet Banana.
    One, two, and the Depot RAR-O, I will buy you a sweet Banana.
    Banana, banana, banana I will buy you a sweet banana.
    Shield, spear and knobkerrie, soldiers in war and peace,
    In war she fights with bravery, I will buy you a sweet banana.

    "Sweet Banana"
    Battle hymm of the Rhodesian African Rifles
    John A. Stovall, Jun 24, 2006
  13. Tim

    JPS Guest

    In message <jp5ng.15193$>,
    I would call that a well-exposed RAW that had an over-exposed in-camera
    or default JPEG.
    JPS, Jun 24, 2006
  14. Tim

    JPS Guest

    In message <[email protected]>,
    Because "correct" JPEG expsoure results in more image noise, that's why.
    To expose correctly for JPEGs is to under-expose for RAW. An ISO 800
    RAW image with +1 EC, on a Canon 20D, has less noise and artifacts than
    if taken as a JPEG at ISO 100 with 0 EC. This gives you two more stops
    of aperture or shutter speed to play with, for the same or better
    results (less posterization, and about the same shadow noise). Shooting
    JPEG allows for at least a stop less exposure, which means double the
    noise, equaivalent to 4x to 8x the ISO, in terms of shadow noise,
    depending on the camera.

    JPEG = lower exposure = higher noise.

    Ideas of "correct exposure" as applied to slide film applies only
    partially to JPEGs, and not at all to RAW.
    JPS, Jun 24, 2006
  15. Tim

    JPS Guest

    In message <>,
    .... and unnecessarily noisy.

    One thing that is really important for people to understand, that very
    few people do, is that exposure affects shadow noise as much as ISO in
    the cameras with shoddy high-ISOs, and exposure affects shadow noise
    *far more* than ISO in cameras with good high-ISO performance, like
    recent Canons. JPEGs have a bit of a shoulder to watch out for, or you
    may want them as-is out of the camera, but if you're shooting RAW, you
    get the best quality images generally by using an aperture and shutter
    speed that gives the highest possible photon exposure on the sensor,
    while using the highest ISO that doesn't clip the highlights that you
    want to keep. Sticking to low ISOs out of principle, and under-exposing
    (which "normal" exposure is, and you're shooting limited-contrast or
    high-key scenes, and you're shooting RAW), is a recipe for higher noise.
    Low ISOs only give less noise when you are comparing at the same EC
    amongst ISOs, and the Av and Tv freedom allows the same relative
    (histogram) exposure at all ISOs; ISO 100 at -0.5 EC has as much noise
    as ISO 1600 with +1.5 EC on my 20D. Shooting a low-contrast or high-key
    scene at 0 EC and ISO 100 is a false security. Better results can be
    had with a higher EC at ISO 100, if the Av and Tv values permit, or to a
    (not much lesser) extent, with a higher ISO and the same Av and Tv

    I run into so many people in the field who are shooting in low light,
    with a rule never to use above ISO 400, with 20D and 1DmkII cameras,
    which clearly give much better results at higher ISOs with higher ECs.
    JPS, Jun 24, 2006
  16. Tim

    JPS Guest

    In message <>,
    .. than 35mm color films. MF and 35mm B&W still have higher resolution.
    JPS, Jun 24, 2006
  17. Tim

    Stacey Guest

    Depends on the camera, some produce more detail with RAW using the right
    processing engine.
    Stacey, Jun 24, 2006
  18. Let's see if I've got this right ...

    The other day I was shooting some coastal scenes on a 20D (RAW Mode) - the
    images on the built-in monitor looked correctly exposed, but the histogram
    only had entries across the first 3/4 of it's scale.

    Adjusting my exposure so that the image stretched across the full range of
    the histogram the image appeared to be at least a couple of stops

    If I'm understanding this correctly, what I should be doing is exposing via
    the histogram, and not by looks because the image will contain more shadow
    detail (infact, more information at every level) - to get the image looking
    correctly exposed one would then need to adjust it with levels and curves.

    Basically in the right track?
    Mick Anderson, Jun 24, 2006
  19. Tim

    My View Guest

    Also an excellent article in the latest pBase Magazine using Channels to fix
    underexposed areas of a RAW image (with required adjustments for jpeg).

    Go to www.pbase.com and download Issue #5.
    My View, Jun 25, 2006
  20. Yes!

    With film it was "Expose for the highlights and develop for the
    shadows..." Hmmm, with digital you can expose for the
    highlights, and then convert for whatever part you want to
    Floyd L. Davidson, Jun 25, 2006
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.