Random black bands in the frame

Discussion in 'Film and Processing' started by jonathan_divry, Jan 18, 2017.

  1. [​IMG][​IMG][​IMG]
    I shot these with my canon model 7 on some agfa vista 200 in full sunlight. I have no clue where these black bands are coming from and im really wondering why this is happening. I'm guessing its an issue with the shutter timing but I'm not really sure.
    Did this happen to anyone before?
     
  2. Pretty much, there are two possibilities regarding blackness in the (positive) frame.
    One is shutter problems, and the other is something blocking the optical path, such is in front of or behind the lens.
    Focal plane shutter problems tend to make fairly sharp vertical (or horizontal) lines. The first one is nice and vertical, though not as sharp as I would expect for a shutter problem.
    If you listen carefully, you can hear the sound of some shutter problems. For speeds of 60 or slower (for most focal plane shutters, and especially old Canons) there should be two separate sounds, the first curtain moving, and the second. Changes to those are often audible.
    For 125 and faster, there should be one sound. (I have a Canon VI, and am used to its sound. The 7 might not be so different.)
    The second one is hard to see as a shutter problem. The third, with the dark band in the middle, seems not so likely, but possible. What shutter speed (about) were these done at?
     
  3. Since you ask in "Film and Processing", and not in "Classical Manual Cameras", do you expect the possibility of development problems? Did you develop these yourself?
     
  4. James G. Dainis

    James G. Dainis Moderator

    Does that extend into the film rebate or edge where the frame numbers etc. are? If so it is not the shutter.
     
  5. Could the film have been improperly loaded onto the developing reel? Sometimes, if the film is not within the slots in the reel, it can kink and make contact with the film in the next slot.
    This prevents the developer from reaching the film, causing that portion to be undeveloped. This will be clear, or almost clear.
    Check your negatives. There will be clear stripes corresponding to the black stripes in the positive images. Is the edge lettering properly developed, or is it clear? If the edge lettering is affected, it is almost certainly a developing problem. If not, then it is a camera issue.
     
  6. Thanks everyone for answering so quickly
    @Glen H
    These were in full sunlight so i set my camera at f22 and 1/1000th
    Also these were developed in a shop but if I recall correctly it did happen before
    @James Dainis
    Its hard to tell since the film edges are originally transparent but then lettering seems to be intact
    @Paul Noble
    This was done at a pro shop so I dougbt that could be the issue. Following your advice, the edge lettering is not affected so I guess I will investigate further with that in mind!
     
  7. If the film is loaded improperly, the usual state is that it doesn't develop or fix, and comes out white on the print. It is also easy to see, as it has the whitish look of undeveloped film, when you look at the negative.
    If one took the film off the reel between developer and fixer, or refixed the film later, then it would be clear, and black on the print. This is rare, and you should know that it happened.
    It mostly reminds me of some object, finger or strap, in front of the lens, but not quite enough to be sure of that.
     
  8. James G. Dainis

    James G. Dainis Moderator

    I'd like to see what the negatives look like. Could you take a photo of a strip of six frames against a white background and post that?
     
  9. It could also be some object between the lens and shutter.
    In any case, you might try looking through with the back open, and operating the shutter, while pointing the camera at a light source.
     
  10. [​IMG]
    Here's a picture of the negatives
    there doesn't seem to be anything blocking the lens when shooting
     
  11. The camera needs servicing. The shutter is malfunctioning.
    The shutter is all metal, coated stainless steel curtains that travel horizontally.
    According to http://www.photoethnography.com/ClassicCameras/Canon7.html its hard to find one that does not have crinkled shutter curtains and the crinkles are not a problem unless the shutter sticks, yours sticks.
    A focal plane shutter in a 35mm camera has two curtains. In the cocked position curtain 1 blocks the light path to the film. When released curtain 1 starts to clear the light path and curtain 2 is released depending on shutter speed creating a slit as wide as the image opening on 1 second to a slit about 1/8 inch wide on 1/1000. Both curtains should run at the same speed.
    What is happening is one of these possibility, curtain 1 is sticking partway across the image opening and curtain 2 is catching up with it, curtain 2 is running faster than curtain 1, or curtain 2 is being released prematurely or is sticking to curtain 1. The two curtains mate to prevent a light leak when cocking the shutter.
    While I've following this thread I did not respond earlier as I had nothing more to add to the accurate information posted and questions asked by the other members.
     
  12. I agree that the shutter is likely the cause of your issue.
    I will add that, unless you are intentionally underexposing your film, Sunny Sixteen says proper exposure with ISO 200 in bright sun is 1/250 at f16. 1/1000 @ f22 would be 3 stops under, by my calculations. Shutter capping is typically more obvious at higher speeds, so you may be able to get by with slower speeds, if funds are not immediately available for a CLA.
    Also, it could just be grit and dust in the channels the shutter travels in that may be causing the problem. Particularly if the camera has sat unused for a long time. If so, there is a chance that the problem may resolve itself with use. (Wouldn't get your hopes too high, though.)
     
  13. Since we don't know what the pictures are of, is there a black band in frames 0A and 1A?
     
  14. Alright thank you guys
    Sorry for the late answer I just
    got back to my country after a
    long vacation.
    I will look into fixing the
    shutter ane maybe blowing
    compressed air into the rails to
    get all the dirt and grit out. If
    the issue reoccurs ill get it
    fixed professionally.
    Ane no thwre are no bands on A0
    and A1
     
  15. Not so sure you should blow in compressed air. When I worked for a photo company, I saw an employee blow out a shutter curtain that way. If you do try it, be VERY careful.
     

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