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Thread: 645d green fidelity

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    645d green fidelity

    Don't know if someone also noticed: greens from the 645d are too
    green, too pleasing, and blues too saturated also.
    First example is from a g1, and colors are (winter)spot on.
    Second example,from 645d, much more pleasing, but totally not correct.

    G1

    _1050772 by sergio lovisolo, on Flickr

    645d

    _IGP1370 by sergio lovisolo, on Flickr

    Sergio

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    Re: 645d green fidelity

    Hi Sergio,

    With the 645D, it's not something I've looked and tested for, so it will be interesting to note what other observed wth their 645D. From the two images you posted, it appears there is an over abudence (ie: too much) cyan, which can be seen not only in the change in the hue of the pines of the tree but in the sky too.

    Many manufacturers digital cameras often have a bias towards one primarily color or another, which often is readily seen.

    Dave (D&A)

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    Re: 645d green fidelity

    Sergio:

    My greens are very realistic; some reds cause problems and end toward magenta however. I assume you are comparing RAW files.

    Tom

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    Re: 645d green fidelity

    Dave, thanks for the "colorimetric"explaination.
    Tom,yes, raw files converted in ACR 6.5 no corrections for both.
    The greens are very pleasing for aerials in winter,but far from reality.
    Sergio

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    Re: 645d green fidelity

    I have found my 645D to give very accurate color for greens and blues in winter and other seasons.

    What were you using for white balance. When I look at the two images above, what I see is the G1 image to be more yellow which would account for the change in the greens and blues. What you really need to do is photograph a color checker--how do we know if either of these photographs is accurate?

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    Re: 645d green fidelity

    Shashin, the color checker is in front of me. This three is in my garden, and i can immediately and directly compare to what I see on screen.
    But I'll follow your advice of using a color checker card.
    Thanks.
    Sergio

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    Re: 645d green fidelity

    [QUOTE=Shashin;395514] What you really need to do is photograph a color checker QUOTE]

    The suggestion by Shashin of use of the color checker is of course ideal, especially when two cameras are used to compare the color balance of one vs. the other. With regards to this and of course in particular the testing of the 645D alone, careful attention needs to be paid to first properly white balancing against a netural gray card etc. I wonder can it be possible that individual bodies of the same cameras display different color balances in RAW output assuming all components are are within spec?

    Just out of curiosity, what lens did you use for your tree shot? Is the bias towards cyan (as shown in your shot with the 645D) also eveident when you shoot similar subjects with any other Penatx 645 lenses?

    Dave (D&A)

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    Re: 645d green fidelity

    Dave, this one was with the FA*300 4, but all other lenses give the same result.

    Sergio

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    Re: 645d green fidelity

    Quote Originally Posted by sergio lovisolo View Post
    Shashin, the color checker is in front of me. This three is in my garden, and i can immediately and directly compare to what I see on screen.
    But I'll follow your advice of using a color checker card.
    Thanks.
    Sergio
    Sergio, looking at a tree outside your window and comparing it to your monitor is not an ideal viewing situation. Your eye is going to be doing so many things to your perception and the monitor is really a dicy device to judge--I set up a print lab and with viewing lights and it is not as simple as all that.

    I would at least shoot in a very controlled condition.

    What color temperature and gamma do you have monitor set to? Do you color manage your monitor? What are you using for white balance on the cameras? This information would help me in figuring out what you are seeing. Posting something on the web and saying this is correct color is kind of like me sticking my finger in the air to give you an accurate temperature reading.

    My experience is the color from the Pentax is excellent--I find it better than Phase One and a bunch of Nikon and Olympus cameras I have used.

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    Re: 645d green fidelity

    Shashin, thanks for your help.
    Monitor is an iMAC 27", gamma 2,2 , color temperature 6500. Calibrated only with the internal routine.
    Tomorrow I'll perform a more controlled test, but I have been seeing this strange effect
    with foliage from a long time. I should say I never complained, because it is very useful
    for my aerials, prolonging the season of operations.
    Sergio

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    Re: 645d green fidelity

    Sergio, I think your monitor is good. I profile the monitors in our lab and the iMacs tend to be very close. And a 2.2 gamma at 6,500K is also good.

    I would also test how each camera does WB among auto, preset, and custom. The nice thing is you can also make adjustments to the WB. WB does not affect RAW, but you might find a better or more consistent solution for color when it opens in the RAW processor. I carry an E-P1 in my camera bag for snaps and the Olympus color is very different, especially under warmer conditions such as late in the day and tungsten.

    One of the biggest problems with cameras used outdoors is the shooting/color conditions vary widely from hour to hour, day to day, and season to season so profiling them is really tricky. I shoot RAW so WB is a moot point, but I do notice that the "as shot" and presets in the RAW processor are different and not always in favor of "as shot" which I find I usually prefer. And sometime I do touch the sliders.

    And I don't know the significance of the DR and contrast here--your G1 image does not have the same contrast. Contrast alone will impact color and saturation.

    But first, I think you need to identify the "problem." But if your only problem is the Pentax has more pleasing color, I am not sure I can think of a better problem.

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    Re: 645d green fidelity

    Today is overcast, dull light, so both cameras WB on cloudy.
    Scene at 3 meters distance, so I can clearly evaluate colors.

    G1

    _1050785 by sergio lovisolo, on Flickr

    645d

    _IGP1379 by sergio lovisolo, on Flickr

    and the following one is my best trial(sliders in action) to mimic reality, I think reasonably accurate.

    reality by sergio lovisolo, on Flickr

    It is not a WB problem. Both cameras produce too vivid conversions, but the 645d is really exaggerated, and requires reprofiling, at least with Photoshop ACR 6

    Sergio

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    Re: 645d green fidelity

    Sergio, you have two choices at this point. You can either just find the relative change required in ACR/Photoshop and process each image that way or you can try to build a profile for your camera. There are kits out their that will let you do camera profiling.

    I would also get a good book about the ins and outs of color management, Real World color Management, for example, just to get a good picture of what it does and does not do. Color is a really trick thing. Or at least it can be when you are getting to the point where you are questioning your camera's color and you have a definite idea of what you want to achieve.
    Last edited by Shashin; 4th March 2012 at 15:20.

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