I agree with those who advise keeping pressure on the back plate during slide removal. I used to keep the darkslide just barely tucked in the holder slot during exposure, until a little bit of breeze came along and turned the darkslide into a wind flap and, well, I don't do that anymore.
Hi Michael,
Any fogging on the printed image or just light leakage on the film edge? I happen to experience the same problem just now. Thanks,
Aaron
Aaron,
The problem is primarily in the corners and does sometimes extend into the image area. Storing the slides seperately may have been a crazy practice, but I'm convinced it helped stave off the problem with these old holders.
Thanks Michael. Appreciate it. Aaron
As an internet newcomer I was impressed about the variety of themes in regard of large format photagraphy in this website.
May be I can contribute to this discussion about filmholder light leaks. I have had simular problems with my High Fidelity 13/18cm film holders and now they are leakproofed.
When I was reading this problem from Michael I must think about the problem solving theory from Kepner Tregoe, which helped me a lot during my professional life as a development engineer. In short termes: Most important is thorough analysis at the beginning and not to follow unorganized the first ideas or theories. To prevent this some basic questions has to be answered. What is the problem and what not? When it occurs and when not? Who has this problem and who not? These questions seems to be obvious, but you can come to conclusions, where you have normally not thought about. In our case the questions must be: Have all holders this problem? Shows a specific holder repeatable leakeffects? Since when you have realized leaks? Have you only one kind of leaks?......Such a carefull questinnaire helps to look not only for one effect and then later to find others. I have had some negatives from impressive motifs from a Iceland trip, which were nearly waste, which forced me to analize the situation afterwards (such tests we should make before or after a secondhand business!). My analysis guide me to the following leak sources:
1. On used cameras check whether the elastic "light-sealing" of the camera back (out of poyurethane, soft rubber or black velvet) is still in good condition or may be is too porous, too much compressed or shrinked. The problem is, that we normally cannot see these areas.
2. Black areas on right or left bottom side of the negative were caused in my case by aged platic tape, which is used as hinge for the bottom lid. This material gets pervious for light by wear (can be checked by holding agaist a small light source). I have sticked a new black tape above the old and cut it thoroughly around the shape of the bottom lid.
3. I have found among my 10 film holders some, where the bottom lid has shrinked (as it is a normal risk with elastomeres) and this has caused two thin corner channels for light, if the slider is opened. This can be reduced by the tape operation from 2. if the tape is cutted exactly. Otherwise the film holder can only be thrown away.
4. The same cause as in item 3. is the source for leakages right and left on the top of the negative long side. There happens another shrinking effect between the welded or glued plastic parts, which can cause one or two light channels to the negative, if the slider is opened. These channels (approx. 0.3/0.3 mm )can be closed by some layers of black yarn and fixed with glue afterwards.
Items 2. to 4. can occur only if the slider is open i.e. during the exposure time. I have tested my holders although in closed position with and without the slider and have not found any effect of additional leaks. Therefore minimum in my case the light sealing of the slider was not leaking, what is understandable because there is a bronze double lipseal , which seems to be ok even after a long life. (But on my Linhof rollfilm back this sealing is made out of rubber and was after 20 years totally porous and was changed from me against velvet).
A very important hint was given from Pete Andrews in regard of the necessity of care during lifting the slider because of the limited springforce of the screenholder, which is reasonable for the contact sealing in this area.
So I hope my english is understanable enough to help a little bit in this annoying theme.
Good success Reinhard
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