Chuck, I know this is the standard safety warning, but it has never made any sense to me. If the pinhole is 1/100 inch (.010") in diameter, and it is in a filter that is 70 mm in diameter for a bino, then the pinhole represents only .00015% of the area. This is a miniscule increase in the energy transmitted. If there were 100 pinholes, the area would still be only .015% of the total. I have actually heard some folks say that the pinholes did NOT matter because they were so small. Your opinion? Brent --- Chuck Hards <chuckhards@yahoo.com> wrote:
As a lot of people re-sell mylar, usually without a copy of the manufacturer's safety precautions, I thought it might be good to remind everyone using mylar:
ALWAYS check it for pinholes before use. If you spot any, do not use it until you've closed the hole with a small piece of opaque tape, or a drop of lacquer. White-Out works well for this. The tape or lacquer will not harm the image at all. The filter won't have to be replaced until it looks like a polka-dot pattern, in fact.
If the hole does not go all the way through the material, but is just a spot where the aluminum has come off the substrate, you can opaque it with a permanent black marker. Usually two or three "touch-ups" are required to get the ink opaque enough.
If the sight of the dots offends you, do it on the back side.
Chuck
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