infrared questions

[chaim]

when you shoot HIE infrared, is it correct to use a #25 red filter? If so, do you set the ASA as if using a Wratten filter--ASA 50? if the filter spec says +2 f-stops, does that mean open up 2 stops over the meter, or stop it down 2 stops?
Thanks,
Chaim

 

[gchpaco]

There are a whole bunch of different filters you can use with HIE, but the 25A is certainly a good one. If you meter without the filter, use ISO 50 and no compensation. If you meter with the filter, ISO 400 and let the camera compensate. The latter is not always reliable. And in any case you're going to want to bracket.

 

[colrehogan]

This site has a good description of the use of HIE with a 25 red filter.

http://mysite.wanadoo-members.co.uk/invisiblelight/index.html

 

[akar]

Hi Chiam,
Quick answer -- I almost always use a red #25 filter when shooting HIE in sunlight (not that there aren't other filters you can use). With the filter, f11 at 1/125th is a good starting point in bright sunlight.

~Allen

 

[aj-images]

I shoot a ton of IR myself and never meter. I use the 25a filter and like Allen said, F11 @ 125th is my starting point. I bracket the hell out of the film, one reason being a 1/2 stop can make a good image great (that is how sensitive the film is) and I get a lot of pin holes in my film. If I think it is a great shot, I will shoot the same image 2 times, both at the same exposure (because of pinholes). - Jim