Cletus
14-Oct-2012, 07:00
I'm not sure exactly where this should be posted, but since it's showing up on my film, why not here?
I'm noticing on many of my 8x10 negatives there is a consistent pattern of "exposure", right about smack in the middle of some of my negatives. I may try to post a scan of this, but it'll be hard to scan and this description might stand out to someone anyway -
The "light leak" mark, if that's what it is, is NOT related to any particular holder, so eliminates that as far as I can tell. The "mark" is shaped something like a scratch, about 2.5-3" long, with some little random scratch looking marks near one end of the anomaly. The "little marks", concentrated near the "top" of the long mark, are consistent with the camera moving before exposure, after the darkslide has been pulled. Although, when I think about it the "camera moving theory" doesn't make as much sense, as the film holder and camera really shouldn't move relative to each other that way after the holder has been inserted. (???) But than again, if it's a point light source on the bellows, I suppose it could still cause the little marks....I don't know....what about the long one then?
This appears both on negatives exposed outside in bright sun and also inside in very subdued light, using a studio strobe. What perplexes me is that the mark is reasonably consistent from negative to negative in size, shape and intensity and appears just about right in the center of the negative in the "axial" or long direction. If were actually a scratch and not an exposure mark, I might think it was sand in my holder light trap, but again, the mark isn't related to any one holder. Overall, the marks are fairly sharp, indicating that the leak - if that's what it is - would be closer to the back of the camera than the front. It seems to me anyway. The "density" of the mark is fairly high, about medium grey (I don't have a densitometer, so can't provide a number).
Here's something else that really makes me wonder - The same mark(s) also appear on a blank negative - the second frame of the same subject that I thought I had exposed (I do this from time to time). The darkslide was still on the white unexposed side and I don't know whether I forgot to cock the shutter, or it misfired, or what? I must have pulled the darkslide though, when I thought I was making the exposure, otherwise the mark would indicate the "leak" is coming from somewhere other than the camera????? I can't think what I'd be doing in the darkroom, while loading holders that could cause this anomaly to be so consistent in size and location from neg to neg?
Anyway, this is about the best description I can make of what I'm seeing with going into one of my 5,000 word essays - I'm working on being more concise :) - and I am stumped. I don't know how, or what kind of setup I'd need to test my camera for this, as I mildly suspect this must be a "point source" leak coming from somewhere around my camera back, or maybe the bellows near the back of my Sinar F2.
Any thoughts on this? Does this ring a bell with anyone, or sound just like something you've seen before? I'm trying to come up with a plan to test the camera and locate this leak, but coming up short on ideas how to do this.
I'm noticing on many of my 8x10 negatives there is a consistent pattern of "exposure", right about smack in the middle of some of my negatives. I may try to post a scan of this, but it'll be hard to scan and this description might stand out to someone anyway -
The "light leak" mark, if that's what it is, is NOT related to any particular holder, so eliminates that as far as I can tell. The "mark" is shaped something like a scratch, about 2.5-3" long, with some little random scratch looking marks near one end of the anomaly. The "little marks", concentrated near the "top" of the long mark, are consistent with the camera moving before exposure, after the darkslide has been pulled. Although, when I think about it the "camera moving theory" doesn't make as much sense, as the film holder and camera really shouldn't move relative to each other that way after the holder has been inserted. (???) But than again, if it's a point light source on the bellows, I suppose it could still cause the little marks....I don't know....what about the long one then?
This appears both on negatives exposed outside in bright sun and also inside in very subdued light, using a studio strobe. What perplexes me is that the mark is reasonably consistent from negative to negative in size, shape and intensity and appears just about right in the center of the negative in the "axial" or long direction. If were actually a scratch and not an exposure mark, I might think it was sand in my holder light trap, but again, the mark isn't related to any one holder. Overall, the marks are fairly sharp, indicating that the leak - if that's what it is - would be closer to the back of the camera than the front. It seems to me anyway. The "density" of the mark is fairly high, about medium grey (I don't have a densitometer, so can't provide a number).
Here's something else that really makes me wonder - The same mark(s) also appear on a blank negative - the second frame of the same subject that I thought I had exposed (I do this from time to time). The darkslide was still on the white unexposed side and I don't know whether I forgot to cock the shutter, or it misfired, or what? I must have pulled the darkslide though, when I thought I was making the exposure, otherwise the mark would indicate the "leak" is coming from somewhere other than the camera????? I can't think what I'd be doing in the darkroom, while loading holders that could cause this anomaly to be so consistent in size and location from neg to neg?
Anyway, this is about the best description I can make of what I'm seeing with going into one of my 5,000 word essays - I'm working on being more concise :) - and I am stumped. I don't know how, or what kind of setup I'd need to test my camera for this, as I mildly suspect this must be a "point source" leak coming from somewhere around my camera back, or maybe the bellows near the back of my Sinar F2.
Any thoughts on this? Does this ring a bell with anyone, or sound just like something you've seen before? I'm trying to come up with a plan to test the camera and locate this leak, but coming up short on ideas how to do this.