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Thread: Color cast on technical cameras.

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    Color cast on technical cameras.

    I noticed that picture in the thread about the IQ3100:



    The picture is taken with the IQ3100 and the Rodenstock 32mm f/4 HR Digaron-W.

    I don't use a technical cam, so this is the first time I see a demonstration of the colour shift. Is this level of colour cast common with lenses designed for technical cameras?

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    Re: Color cast on technical cameras.

    Quote Originally Posted by jerome_m View Post
    I noticed that picture in the thread about the IQ3100:



    The picture is taken with the IQ3100 and the Rodenstock 32mm f/4 HR Digaron-W.

    I don't use a technical cam, so this is the first time I see a demonstration of the colour shift. Is this level of colour cast common with lenses designed for technical cameras?
    This image was processed with C1 9.0.2 which current is adding a green cast to the processed LCC files for the 3100. It's my understanding a fix is in process for this issue. Without the fix its hard to gauge the color cast issues

    If you search on this site for some of voidshatter's posts on other Phase One backs and tech cameras you can see some good examples of the normal red/magenta color cast with shifts. The 23 28 and even the 32 can show a bit of color cast even on center shots.

    Paul C

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    Re: Color cast on technical cameras.

    Quote Originally Posted by Paul2660 View Post
    If you search on this site for some of voidshatter's posts on other Phase One backs and tech cameras you can see some good examples of the normal red/magenta color cast with shifts.
    I have seen other threads, but they only had images of a white reference surface. This is the only time I have seen the shift on a normal subject.

    Of course, it is possible I overlooked another image, I don't follow the threads on technical cams very closely. I am not interested in a technical cam for myself.

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    Re: Color cast on technical cameras.

    Quote Originally Posted by jerome_m View Post
    I have seen other threads, but they only had images of a white reference surface. This is the only time I have seen the shift on a normal subject.

    Of course, it is possible I overlooked another image, I don't follow the threads on technical cams very closely. I am not interested in a technical cam for myself.
    Note that color cast is removed when you apply an LCC. If there's a residual color cast left then it's because there's a software bug (like in the example above) or the sensor is totally incompatible with the lens and then they should not be used together.

    Color cast exists to some extent also in normal cameras, I even see it in my mobile phone wide angle camera if I shoot an even surface. If you make an LCC shot on a wide angle on an SLR you will probably see some small amount also there.

    Tech lenses pushes the limit though so applying an LCC is necessary. The reason we're so obsessed with LCC these days is because today's sensors (the Sonys) have not been designed to be compatible with the tech lenses and when it's pushed past the limit strange things can happen. The Sonys have such much over-capacity in tonality and dynamic range so we're going further past the design limit than was thinkable with previous sensors.
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    Re: Color cast on technical cameras.

    This links shows a bit more of the effects, the LCC's are before, showing full color cast. The image after, but I have plenty of them before and will post one later today. Showing the effect on the file before the LCC is processed.

    Paul C

    http://www.getdpi.com/forum/medium-f...ighlight=IQ250
    Paul Caldwell
    [email protected]
    www.photosofarkansas.com
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    Re: Color cast on technical cameras.

    Quote Originally Posted by torger View Post
    Note that color cast is removed when you apply an LCC.

    I understand that. I also understand the negative effects of software corrections.

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    Re: Color cast on technical cameras.

    Quote Originally Posted by Paul2660 View Post
    This links shows a bit more of the effects, the LCC's are before, showing full color cast. The image after, but I have plenty of them before and will post one later today. Showing the effect on the file before the LCC is processed.

    Paul C

    http://www.getdpi.com/forum/medium-f...ighlight=IQ250
    Thank you for the link. To my eyes, the degradation on the 23 HR lens when shifted 15mm is severe. Not only color cast but sharpness too.

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