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Thread: Raw files from any back on H2

  1. #1
    Panopeeper
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    Raw files from any back on H2

    I found a strange phenomenon in the raw file created by a P30+ on a H2. It indicates some electrical problem; however, the same back on another camera behaved normal.

    Then I checked an older file, this time a P45+ on a different copy of H2: the same phenomenon. Other P45+ on non-H2: nothing special.

    My suspicion is, that the connection between the camera and the back passes some signals, which seriously impede the readout.

    Now, two cases don't make a rule, but if you guys upload raw files (native or DNG) from any back on H2, I verify those. The subject, the exposure, everything is irrelevant, except that it should not be a black frame with 1/10sec (i.e. there should be something in the image). Are PhaseOne backs of particular interest? I don't know.

  2. #2
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    Re: Raw files from any back on H2

    Hi, Gabor,

    Raw file posted for you at http://GibsonPhotographic.com/share/...uye%20Peak.TIF.

    It's a P45+ raw file taken with a Hasselblad H2 and a Zeiss CF 80/2.8.

    Hope that helps,
    -Brad

  3. #3
    Panopeeper
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    Re: Raw files from any back on H2

    Bradley,

    thanks for the file. This one does not exhibit that pecularity (good for you).

    What kind is the connection between the body and the back? Is there a possibility to touch some pins, or can something be dirty?

    The phenomenon I observed clearly indicates some electric disturbance. The effect is possible posterization, and high noise.

    Btw, it's high time to put your P45+ into the dishwasher :-)

  4. #4
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    Re: Raw files from any back on H2



    It's quite possible your P45+ may be defective. I did a number of mount swaps and had image quality issues with two of them. After pointing the issue out to my dealer Phase cross-shipped me a corrected unit and all was OK.

    Ok, let me put it into the dishwasher for you... oh wait... that's right... I just sold it! Sorry, I was all set to do the experiment for ya, but alas, I no longer own it! (Moved to Sinar eMo 75LV/Hy6.)

    I hope you're able to get them to take a look at the issue. Feel free to use my file as evidence that not all P45+'s exhibit what you're seeing.

    Best of luck, Gabor,
    Brad

  5. #5
    Panopeeper
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    Re: Raw files from any back on H2

    [QUOTE=BradleyGibson;35844Ok, let me put it into the dishwasher for you... oh wait... that's right... I just sold it! Sorry, I was all set to do the experiment for ya, but alas, I no longer own it![/QUOTE]

    Bradley,

    I'm afraid you misunderstood my remark re the dishwasher. The sensor of your P45+ was (is?) horrendeously dirty. It looks like a spaghetti plate before rinsing.

    Btw, I don't have any P45+; I analyzed images of others and became alarmed by that error.

    Have fun with your Sinar,

  6. #6
    plasticimage
    Guest

    Re: Raw files from any back on H2

    Hello Gabor,

    Here's a P30+/H2 raw. Could you take a look?

    http://www.plasticimage.com.temp.liv...008430_tif.zip

    Thanks very much.

    Greg
    www.plasticimage.com

  7. #7
    Panopeeper
    Guest

    Re: Raw files from any back on H2

    Greg,

    your camera/back combination is ok.

    I saw this pecularity/fault with two separate combinations of H2 and Phase One, unexplicably. I saw once the same phenomenon with a DSLR modified for infrared. It turned out, that when reassembling the camera (the modification requires disassembling it), the bare end of a connector has been touched by nacked finger, and a shilding connector was not reconnected. After correcting these, the phenomenon vanished and so did the banding.

    Anyway, are you using Adobe Camera Raw for processing of the raw images? (I.e. Photoshop or Lightroom)

    I am asking this, because I noticed, that your shot is one stop lower exposed than it would be possible without any relevant pixel clipping, and that happens sometimes, because the user does not know, that ACR adds 1 EV to the intensity if shot with ISO 400 by this camera (actually, by several - or all - Phase One cameras). With ISO 800 this is 2 EV.

    This automatically applied adjustment is not visible on the "exposure" slider.

    Now, the effect is, that the user sees a much brighter image, and more clipping, than the truth is.

    For example this shot, loaded in ACR and all controls reset to null, shows lots of clipping:



    although in reality there was only a very tiny clipping, shown by the yellow strips here:



    When the shot is severally underexposed, banding can become visible, which is ingherently there in every Phase One image, but normally not visible; the following image shows, what is present in your image (the outlines of the complete image can be recognized, but I turned the image to normal orientation). The separation line in the middle is due to the stitching of the part sensors, normal with this back, but that too may become visible due to underexposure; this is particularly interesting with ISO 800, which shows two stops brigher in ACR that it is.




    Anyway, watch for the camera/back contact, it should not get dirty (one possible source of the problem).

    Have fun

  8. #8
    plasticimage
    Guest

    Re: Raw files from any back on H2

    Thanks for checking it out, Gabor.

    The image was underexposed unintentionally, and I always process in C1. Strangely, I really like the look of slightly "pushed" underexposed files from the P30+ -- they are the most film like images I've seen from digital.

    The "centerfold" line is not something I had noticed in any image, even shot at 1600. I guess Phase must have a calibration tool to compensate...

    Thanks again.

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