Raw photo software

Discussion in 'Digital Cameras' started by Mayayana, Aug 11, 2012.

  1. I'm afraid that all sounds good, but it just is not
    true. Yes, it *does* have to re-render *everything* to
    get another pre-view image.

    You *can't* just remove the white balance and add in
    another white balance.
    So just how do *you* think it is done. There is one other
    way, and I really doubt anyone would write it that way...
    Just you. Round and round.
     
    Floyd L. Davidson, Aug 18, 2012
    1. Advertisements

  2. Mayayana

    Eric Stevens Guest

    You are still evading the question. Does it have any editing
    functions?

    If not, where does Savageduck get the ability which enables him to
    write:

    "However, all of the above, including selective processing via the
    adjustment brush, sharpening, noise reduction, spot correction,
    red-eye correction, spot correction, image alignment, custom &
    fixed ratio cropping, color balancing, application of gradients,
    application of lens profiles, CA & Vignette corrections, creation
    of pre-sets, and more can be done in ACR, either using the CS, or
    LR interfaces."

    - selective processing via the adjustment brush

    - spot correction

    - image alignment

    - custom & fixed ratio cropping

    - application of gradients

    - application of lens profiles

    - CA & Vignette corrections

    - creation of pre-sets

    .... are not functions essential to raw conversion. In fact they entail
    altering the image in some way and can be done at any stage of the
    image _editing_.
     
    Eric Stevens, Aug 18, 2012
    1. Advertisements

  3. Mayayana

    tony cooper Guest

    How do you "remove" white balance?
     
    tony cooper, Aug 18, 2012
  4. Mayayana

    Savageduck Guest

    I get the ability to write the above, because all of the above
    adjustments/edits are available to the user of CS5 when processing RAW
    image files with ACR. I am able to use any of the above listed
    adjustments and edits prior to clicking on the "Open" or the "Done"
    button.


    ....or I can hold the shift key down and click on "Open" so that the
    adjusted RAW file is opened in CS5 as a 32-bit Smart Object.
    True. However, this is the subtle bonus you get by using CS5/6 & ACR.
     
    Savageduck, Aug 18, 2012
  5. Mayayana

    Eric Stevens Guest

    I understand that and am not objecting to your statement in any way.
    I'm quoting it as evidence that ACR is more than a raw convertor. I'm
    probably the only one still sticking with that as the point of the
    argument. :)
    Which was my original point.
     
    Eric Stevens, Aug 18, 2012
  6. Mayayana

    Savageduck Guest

    OK!
    You could say that ACR is a RAW convertor on steroids, and Lightroom
    wraps it all in a package with a bunch of other stuff, such as print
    and presentation options, some serious editing ability, Mapping, and
    the ability to use third party plugins, and presets. There are a few
    things LR won't do, such as the 32-bit Smart Object conversion, but
    that isn't really one of its functions or selling points.


    OK!
    Time to put it to rest.
     
    Savageduck, Aug 18, 2012
  7. Either go back to the original raw sensor data, or to the
    initial uncorrected RGB data if it has been saved.

    Generally that means the RAW converter has to be invoked
    again to generate an uncorrected RGB data set.
     
    Floyd L. Davidson, Aug 18, 2012
  8. Mayayana

    Guest Guest

    don't apply it.
     
    Guest, Aug 18, 2012
  9. Mayayana

    Guest Guest

    i'm not evading at all.

    camera raw is a plug-in. it *can't* be run by itself.

    it can only be run within photoshop or lightroom, both of which add
    editing functions.

    in the case of lightroom, there's no distinction between editing or raw
    conversion, nor does it matter. you make the desired change to the
    image at any time.

    in photoshop, there's a small difference but if you use smart objects,
    you can go back to camera raw from within photoshop, just like you can
    with an adjustment layer.
    he posted a screen shot which shows all of that within camera raw.
     
    Guest, Aug 18, 2012
  10. Yeah right. That's how you know if it is correct, or
    too much this or too little that, is you don't apply it
    and never know what the effect is.

    Some of the silly things you say...
     
    Floyd L. Davidson, Aug 18, 2012
  11. Mayayana

    Eric Stevens Guest

    Which confirms that it's more than a raw convertor.
     
    Eric Stevens, Aug 18, 2012
  12. Mayayana

    tony cooper Guest

    I'm unsure of what you mean. "White Balance" is a point at which the
    color temperature is set. It can be changed, set, and re-set, but I
    don't understand how it could be "removed".

    If you mean white balance can be re-set in an image, then "removed" is
    a poor choice of words to use.
     
    tony cooper, Aug 18, 2012
  13. Mayayana

    tony cooper Guest

    What does that mean? Every image has a white balance factor. It is
    not added or removed, but it can be changed.

    Saying "don't apply it" makes no sense at all in answering a question
    about removing something. You can only remove what is there. If it
    is never there, it can't be removed. White balance, though, is always
    there and cannot be removed. It can be changed, but not removed.

    I suspect that you two are muddling about talking about *adjusting*
    the white balance by applying the white balance tool in the RAW image.
    Not applying that tool does not remove white balance. Setting the
    white balance differently from the first application does not remove
    white balance.

    It's like setting the thermostat in a room. You don't remove the
    room's temperature, you change it.
     
    tony cooper, Aug 18, 2012
  14. White balance is the application of a set of channel
    multipliers. If it has not been set, then essentially
    the multipliers are all three equal to 1.0. It isn't
    actually impossible to "remove" it, but it is not
    exactly reversible because of rounding errors. To get
    the exact original requires regenerating the original
    data.

    Incidentally, if the channel multipliers are all set to
    1.0, the image will look "sickly green". That is
    exactly what something known as UniWB does. If you are
    interested, use Google to track down more information
    about it.

    The only benefit to using 1.0 channel multipliers as far
    as I know is that the resulting JPEG image, while it
    might be horribly ugly, does produce an histogram that
    is very nearly exactly what true "raw histogram" would
    be. Since to date no camera manufacturer has yet
    decided to generate a raw histogram, using UniWB is a
    way to get an extremely accurate histogram. It is
    entirely possible to set exposures to within 1/10 of an
    f/stop of obtaining the maximum dynamic range for any
    given ISO. It requires shoot in RAW mode, as the in
    camera JPEG is useless for anything other than generating
    an accurate histogram.
     
    Floyd L. Davidson, Aug 18, 2012
  15. The "thermostat in a room" analogy is not good. In
    essence, if it is used in practice, the results will
    be flawed by accumulating rounding errors.

    The sensor data in the RAW file that is demosaiced to
    form pixel data, which is in a three channel (RGB) 16
    bit format, has absolutely no White balance applied.
    White Balance is applied to the raw data as it is
    demosaiced (it could be applied to the RGB data after
    demosaicing, but that reduces precision).

    To set any preset "color temperature", the data
    necessarily must either not have yet had any channel
    multipliers used or those multipliers have to be
    removed. That could be done with a custom multiplier to
    convert from one multiplier to a different one, but due
    to rounding errors the accurate method is to start
    without any previous application of multipliers. And by
    simply restarting with unaltered data there is no need
    to even know what previous WB settings have been used.

    The operation to set any given white balance requires
    adjusting each of the three channels with a multiplier.
    The values differ with each sensor, so each model of
    camera has different values of multipliers for any given
    "color temperature". Worse yet, just exactly what the
    actual "color temperature" is is not well defined
    either! There are different accepted ways of
    calculating color temperature...

    For example, with a Nikon D4 one of the WB presets is
    "Cloudy", and if that is set the multipliers are 1.0 for
    each of the two Green channels, 2.1778125 for the Red
    channel, and 1.30078125 for the Blue channel. The numbers
    are recorded in the Exif data with every image.

    The Nikon manual says that is a 6000K temperature.
    However, the preset for 6000K is very slightly
    different, with Red at 2.171875 and Blue at 1.296875.

    Regardless, if those are plugged into UFRAW, that
    program calculates the color temperature as 5680 for one
    and slightly higher for the second. And if UFRAW is set
    for 6000K it will use multipliers of 1 for the green
    channels, 2.339 for Red and 1.307 for Blue.

    All are close enough for most people, but someone who is
    doing proofing work needs to know exactly what the
    differences are.

    As with other raw converter parameters, each time the WB
    is changed the preview image will be recalculated to
    show the effect. The WB is not adjusted from the last
    setting to a new setting, it is simply rendered from the
    very beginning. The preview image is not full size, and
    the raw conversion can be optimized for speed. When
    everything is "finished" a conversion is done at full
    size and optimized for quality.
     
    Floyd L. Davidson, Aug 18, 2012
  16. Mayayana

    tony cooper Guest

    This is an election year, so I'm used to a volume of rhetoric that
    sounds like it says something, but - when examined - doesn't address
    the point at all.

    I repeat, "How do you remove white balance"?

    In that muddle of rhetoric you seem to saying that there is a default
    white balance where all three multipliers are equal to 1.0. My
    position is that this can be changed, but it cannot be removed.
     
    tony cooper, Aug 18, 2012
  17. Mayayana

    tony cooper Guest

    Please refer to my other post on the subject of a volume of rhetoric
    that doesn't address the point. You have added to the volume, but
    still have not addressed the simple question: "How do you remove
    white balance?"

    I congratulate you on the introduction of the problem of rounding
    errors in the analogy of changing the temperature by adjusting the
    thermostat. You have ascribed an error of precision to an action of
    change where no numerical result has been mentioned. And done so with
    a straight face! As if it actually means something!
     
    tony cooper, Aug 18, 2012
  18. That is true. We get a constant stream of that from
    Republicans on a normal basis, and now we're absolutely
    being flooded with it.

    Perhaps you've been numbed to the degree that you simply
    can no longer follow any valid logic? The only thing
    is, I don't recall that you've ever been able to, at any
    time!
    I just gave you an in depth butairly concise description
    of how it works, including enough information to abuse
    you of several odd notions you seem to want to bring to
    the discussion.

    Read it again, until you understand it. Every word was
    included because it counted. Do not skip through it.

    I have no need to rewrite it...
    I guess it's just too much for you to understand Tony.

    *There is no default white balance.* If you don't think
    so, then just try to calculate the color temperture with
    a Nikon D4 that is set to use multipliers of 1 for each
    channel.

    And keep in mind that is exactly what the raw data
    recorded in the NEF file is, plus I am in fact using a
    preset WB intended to change that as little as possible
    (granted that it is off by 4/1000ths, but Nikon lists
    two multipliers for 6000K that are different by the same
    amount). The green images do not have a "color
    temperature", and you can't just crank it up or down.
     
    Floyd L. Davidson, Aug 18, 2012
  19. Mayayana

    Guest Guest

    it is true.
    nope. it might in some cases, but certainly not always.
    sure you can.
    it has a list of edits that are applied to the raw which are rendered
    on the fly and it caches some of it for speed.

    if you make a change to sharpening, for instance, the white balance is
    still valid and there's no need to recalculate that. as i said, that
    should be obvious but apparently it isn't.
    what way is that?
     
    Guest, Aug 18, 2012
  20. Mayayana

    Guest Guest

    that's funny. it's the same as what you said in your response to him,
    except your response was full of technobabble about multipliers and
    coefficients.

    you're arguing just to argue.
     
    Guest, Aug 18, 2012
    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.