Blown Out Highlights Question

Discussion in 'Digital Photography' started by JeffS, Aug 15, 2004.

  1. JeffS

    JeffS Guest

    I have several shots which I am happy with for the most part, except for
    a few areas in them where the highlights got blown out. Here is one
    example: . The areas to the right of
    the beak and to the left of the upper wings are kind of nasty. I tried
    using Photoshop Elements' burn tool to tone those areas down a bit, but
    wound up with them just turning grey (no real surprise there, but I
    thought I'd try it anyway).

    Does anyone have some suggested techniques they would care to share to
    diminish or fix the blown out spots during post-processing? I usually
    shoot using the largest (highest quality) JPEG mode. I know I probably
    should be shooting in RAW mode to have a better chance of fixing the
    problem, but I'm still saving for a few decently sized (2 GB or more) CF
    cards and doing research on the RAW processing software available.

    Any help or advice would be greatly appreciated.

    Thank You,

    JeffS, Aug 15, 2004
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  2. The blown highlights are clipped ... that is to say they saturated the A/D
    converters. The information is just not there. No amount of
    post-processing can do anything but "fake" what might have been there.
    Charles Schuler, Aug 15, 2004
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  3. JeffS

    JPS Guest

    In message <>,
    RAW will buy you some extra highlights, as you suggest (on most, if not
    all cameras). In the meanwhile, you basically have two options:

    1) Set the exposure compensation to a negative number. This will
    decrease the signal-to-noise ratio, but will help prevent the blow-out.
    You can then use the gamma adjustment or a custom curve to get your
    midtones and shadows where they should be, without losing the
    highlights. If you are already shooting at a high ISO, you can lower
    the ISO to get the same aperture and shutter speed, if necessary.

    2) Use a custom parameter set and set the contrast to -2. This will
    squeeze more dynamic range into the image, and you can change things
    with the curves tool later to your taste.

    JPS, Aug 15, 2004
  4. JeffS

    Alan Meyer Guest

    I agree with Charles. The data never got recorded in the
    first place. If so, switching to RAW mode would not
    have helped at all. The highlights were just too bright
    for the sensor to see it as anything other than maximum

    There may be solutions at the time you take the photo.
    You could reduce the exposure or, possibly, the
    contrast (something I think you can do in some digital

    Alan Meyer, Aug 15, 2004
  5. JeffS

    JPS Guest

    In message <>,
    Actually, the detail in that particular image probably survived the
    clipping point of the A2D coverter. This image just barely clipped, as
    there are many 253 and 254 values in the middle of the bright areas.
    The RAW -> JPEG converter in the firmware simply discarded the
    highlights (compressed them all to the max value) present in the
    digitized RAW data.

    JPS, Aug 15, 2004
  6. JeffS

    JPS Guest

    In message <>,
    You have some major misconceptions about RAW mode. RAW mode is not just
    a finer resolution of light levels; it is a wider range. For example,
    if you shoot at ISO 100 on a 10D, with daylight white balance, 0 to 255
    in the JPEG will correspond to about 100 to 1500 in the RAW data for the
    red channel, and about 100 to 2100 in the green and blue channels.
    That's out of 4096 possible levels. The JPEG actually throws away
    levels 1501 to 4095 in the red channel, and 2101 to 4095 in the blue and
    green channels.

    I kid you not.
    JPS, Aug 15, 2004
  7. Yep, that's what "blown out" means -- no detail there to be
    There's no really good "win". But in toning down blown out areas,
    injecting some noise often help avoid the horrors of the plain gray
    look. This rarely works if they're too large -- even with noise they
    look fake. But I've sometimes gotten it to work with smaller areas.
    Or sometimes you can steal a relevant pattern or texture elsewhere in
    the image and clone it in, then perhaps adjust brightness and color.

    All of these are a royal pain, lots of trial and error, lots of time,
    and dont' work in many cases. So if you find something really clever
    and easy, do please let us all know!
    David Dyer-Bennet, Aug 15, 2004
  8. JeffS

    Ken Weitzel Guest

    Agreed that "faking" is the only possible option, but
    given that I wonder if cloning other bits of vegetation
    might not be better than nothing?

    Ken Weitzel, Aug 15, 2004
  9. JeffS

    Ryadia Guest

    Ahhh. The contrast ration thing.
    Missing from the OP's message is the camera details. However...
    Digital cameras such as Canon's 10D come from the factory with multi
    point metering enabled. Worse, they have multi point focus set as well
    so the chances of someone unpacking one of these jiggers and taking
    correctly focused pictures - let alone correctly exposed ones is remote,
    to say the least.

    With a DSLR like the 10D you can (thankfully) set the focus to a single
    point and you can also set the metering to a single point (or several)
    as required. You might find setting the metering to the centre sensor
    point (if you can) will result in better metering for the subject.
    Certainly setting the focus to one single point will result in sharper

    Consumer "happy snapper" cameras might not have the ability to alter the
    metering point. How would I know if yours can when you don't say what
    brand, much the model of camera you have? RAW data capture seldom gives
    you more detail in highlights. It will however allow you to capture a
    lot of detail in the shadows (in a decent brand camera) so if you meter
    for correct exposure in the highlights, using Photoshop elements "fill
    flash" facility, you can open up the shadows and get a better exposed

    Ryadia, Aug 15, 2004
  10. JeffS

    Alan Meyer Guest

    Aha! So RAW is 12 bits / channel instead of 8!
    I didn't realize that.
    I believe you.

    Jeff: Sorry for my misinformation.

    JPS: Thank you for educating me.

    Alan Meyer, Aug 15, 2004
  11. JeffS

    leo Guest

    The caption of the picture indicated it's taken from Canon 300D. I have that
    camera too. When I focus using half pressing shutter technique, I would
    think the exposure mode is switched from matrix to center point as well. I
    found that most of the pictures taken this way render underexpose about 2/3
    to 1 stop. Is this normal? I don't set to EC +1 because highlight could
    easily be blown when there're a bright sun in some occassion.
    leo, Aug 15, 2004
  12. JeffS

    JeffS Guest

    Ahhh, I get what you are saying. I shall try that in the future as the
    general conditions I normally shoot in are fairly similar. Bright
    sunlight blasting through fairly dense growth onto reflective things
    like leaf litter and (the worst) white coral rock. I have tried exposure
    bracketing in burst mode (as some have suggested in other threads) to
    try and overlay areas. I'm afraid my technique in Photoshop is sadly
    lacking to pull this off with much success. My subjects (animals/birds)
    tend not to remain still for long and I'm usually shooting freehand. So,
    I usually mess up when trying to align things in PS.
    Another good idea. I will try that also. Really appreciate the tips!

    Best Wishes,

    JeffS, Aug 15, 2004
  13. JeffS

    JeffS Guest

    Sometimes I do find small amounts of detail remaining in some shots.
    That's why I try the burn tool initially, just to see if anything at all
    is there. In a few rare cases, there is just enough information left for
    me to at least partially rebuild the area (if small) in a convincing
    Yep. I've tried everything you've mentioned. With about the same
    failure/success rate you seem to be indicating. At least I know I am on
    the right track for smaller areas. I just wasn't sure. I frequently use
    the methods you mention to remove distractions from an image (like a
    portion of a vehicle or chain-link fencing). While a pain, in some cases
    it is an interesting challenge to see if I can clone a convincing
    pattern/texture. In other cases, it just isn't practical or workable.

    Thank you for the response! One thing I have learned ... the easiest way
    to smooth post-processing work is to get the shot right to begin with. I
    am learning. Slowly, but I am deleting fewer images with each outing.

    Thanks Again!

    JeffS, Aug 15, 2004
  14. JeffS

    JeffS Guest

    No problem. I appreciate that you took the time to read and respond to
    my question! I was aware from some of Mr. Sheehy's other informative
    posts about RAW having additional information over JPEG that could save
    certain shots. I just need more experience with it once I finish
    researching RAW software. I'm just a hobbyist, so nothing fatal in my
    making mistakes. I'm learning by trial and error, plus a healthy dose of
    help from posters like yourself in this newsgroup.

    Best Wishes,

    JeffS, Aug 15, 2004
  15. JeffS

    JeffS Guest

    Sorry, I did leave out information about my equipment. I use a Canon
    300D. I have it set to use only the center focus point. Not sure how to
    alter its metering modes though. Back to the manual and experimentation
    for me.


    JeffS, Aug 15, 2004
  16. JeffS

    JPS Guest

    In message <>,
    That's not true. For a JPEG set to contrast 0 (default), and daylight
    white balance, the RAW file has about one stop more highlights in the
    blue and green channels, and about 1.5 stops more in the red channel,
    used for full RGB color. Then, the red channel also has another few
    stops of highly posterized highlights cramped into a small range at the
    top, used by Adobe Camera RAW and Capture One converters as greyscale
    JPS, Aug 15, 2004
  17. JeffS

    JPS Guest

    In message <>,
    These tips are for JPEG. That doesn't mean that you shouldn't try RAW,
    as RAW will give much better results for scenes with high dynamic range
    (and are less likely to need compensation at all).
    JPS, Aug 15, 2004
  18. JeffS

    JeffS Guest

    Understood. I've learned from other threads that RAW mode (at least for
    my model Canon and many others) bypasses/ignores the parameter settings
    and leaves all that for post-processing. Still, useful information
    nonetheless. Appreciate your responses and time.

    Thank You,

    JeffS, Aug 15, 2004
  19. I experimented with the clone brush in Paint Shop Pro. It could fix the
    areas, with a lot of patience and attention to detail.
    Marvin Margoshes, Aug 15, 2004
  20. JeffS

    kashe Guest

    From the caption area below the picture:

    Canon EOS 300D Digital Rebel
    1/200s f/6.3 at 130.0mm iso400 with Flash full exif
    kashe, Aug 16, 2004
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