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  1. #1

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    Dust & Darkness (Mamiya 645 1000s)

    I just got back my first roll from my "new" Mamiya 645 1000s. I have two questions now...

    1. There is a large squiggle of dust on every single frame, in the exact same spot. I've investigated every part of the camera with magnification and don't see any noticeable dust. or fuzzies. Where in the camera would dust be that would be consistently on every frame?

    2. Several of my images are dark on one side - the top of my landscape shots, on the side for the portrait shots. It's a gradient darkness and always on photos shot at either 500 or 1000 shutter speed, but other photos at the same shutter do not have the dark side. What would cause one-sided darkness?

    I greatly appreciate your input. This is my first run with medium format fun!

  2. #2

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    Welcome to APUG.

    Does the dust/squiggle remain EXACTLY at the same spot and in exactly the same shape and orientation? Is it sharply defined? About where in the frame is it? Middle or at the edge? Can you scan the image and post it?

    Your camera has a focal plane shutter. You can think of it as a SLIT is moving across right in front of the film. I wonder if it is sticking or dragging at high speeds? If you open the back and remove the insert, then trigger the shutter, you should be able to see this. Is the orientation of the dark band same as the direction that this slit travels?
    Develop, stop, fix.... wait.... where's my film?

  3. #3
    MattKing's Avatar
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    Is the dust actually on the negative, or are you seeing it only on prints or scans?

    If the latter, it isn't the camera.
    Matt

    “Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

    Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2

  4. #4

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    It is in the exact same spot, in the same orientation, and doesn't more or change. It looks like a question mark on every frame. Here is a frame showing location - to the left side about half and inch from the edge, and about an inch or so from the top. Also a close up of the squiggle.

    I also attached an image showing the dark side that happens. I removed the insert and triggered the shutter, but I'm not sure what I'm watching for. Can you clarify that last part? (Sorry, newbie here.)

    Click image for larger version. 

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  5. #5
    MattKing's Avatar
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    Like the photo .

    Can you see the "squiggle" actually on the negative or slide, or are you only seeing it on print or a computer screen?

    If it is only visible on a print or a computer screen, it is dust in/on a scanner.
    Matt

    “Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

    Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2

  6. #6

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    It looks to be on the actual negatives. And on two rolls.

    And thanks, I'm a film addict, but also a beach addict.

  7. #7
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    These were processed and scanned by a lab, right? It looks like there is a hair on the lab's scanner glass. Given that it's white on a scan from neg, we know the hair is recorded post-exposure (if it was blocking light pre-exposure, it would appear as black in the final image). So I don't reckon there's hair in the camera unless it's magical glowing hair or something.

    That darkness in the upper-right corner looks like you used a polariser, which can cause unevenness in skies. It could also be uneven shutter curtain speed (the building looks a little darkened too...), e.g. if the first curtain opens a little slowly in one direction, you will get darkness on that side. If the shutter speed is uneven, try looking through the shutter at flashed white surface. If the shutter slit at high speed is narrower on one side than the other, then there's your problem. It will be very difficult to setup a test where you can directly observe this though.

    If you don't mind burning a little film (2 frames!), and assuming the shutter is the typical reversing kind (moves one direction then the other on alternating frames), there is a simple test that has a chance of working. Point a flash and the camera at a white wall and take two consecutive photos at 1/1000. The flash should appear as a stripe across the frame (you are way above x-sync here) and on consecutive photos, it should appear on opposite sides of the frame. If the flash stripes are recorded as different widths, you know it's a shutter-unevenness problem.

    Before you do that though: are the darkened frames all odd-numbered or all even-numbered? If not, then you may have some other problem.

  8. #8
    MattKing's Avatar
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    Are the negatives sleeved?

    If so, do you still see something when you remove the negatives from the sleeves?

    Can you see evidence of there being something physical on the negatives themselves, or is it an image of something visible in the negative?
    Matt

    “Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

    Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2

  9. #9

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    Interesting... they were scanned by a lab, and they are all definitely white, so I will assume it is something with the lab scanner. Definitely no fur growing on my camera. It's super clean, thus my surprise at the marks.

    As for the darkness, I didn't use a polarizer or any type of filter. They were all shot with the 80mm 2.8 Mamiya lens. I don't think it's an even/odd frame thing either. One entire roll has very dark halves of photos. I might need to try the flash test, I suppose.

  10. #10
    polyglot's Avatar
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    Are the dark halves on alternate sides? Do they only occur at high speeds or at all speeds?

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