Harrison IR Filter -- please advice

panya w. · November 10, 2002

Hi,

I have just purchased a Harrison IR Filter for use with my digital

camera. It arrived yesterday and to my surprise, it does not seal

all the light around the filter ring. See picture:

You can see the white uneven circular background between the filter

glass and filter ring.

Is this normal? Using it with digital camera probably OK as I have

use Cokin P type IR filter with digital before, but will this light

leakage around the filter ring cause any fogging if I use it with IR

film? Do all Harrison filters exhibit this feature or this one is

really poorly made? I appreciate your responses. Thanks.

kevinteo · November 11, 2002

I think you may have the wrong impression of what causes

fogging. If you load your camera in total darkness, and your

camera doesn't use infrared LEDs to advance the film, there

shouldn't be fogging. The use of infrared filters only regulate the

amount of visible light that strikes the film. If you don't use a filter

at all, then monochrome infrared film will function pretty much

like most panchromatic black and white films; i.e. you lose the

infrared effect. I guess that the only consequence from this

apparent leakage of visible light will be the attenuation of the

infrared effect.

Recommended Posts