Brent: Pinholes do not come in a "standard size"; indeed for the hole size you mention, you are quite correct in that the throughput is miniscule. But if the hole is just a bit larger, say .050" (4x the unfiltered area of a .010" hole), then I think it's time to get concerned, especially when the eye will be at the eyepiece for an extended period. To err on the side of caution, if you don't have a measuring loupe, just opaque them all and don't worry about it. Safety aside, pinholes can have a harmful effect on contrast. Chuck --- Brent Watson <brentjwatson@yahoo.com> wrote:
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
__________________________________________________ Do You Yahoo!? Yahoo! - Official partner of 2002 FIFA World Cup http://fifaworldcup.yahoo.com