Filter question

[colyn]

I picked up a couple of rolls of Ilford SFX 200 from freestyle which I plan to shoot high contrast. I have 2 red filters the #25 red and a Ednalite series VI infra-red filter. This is not the deep red filter but appears to be 2-3 stops darker than the #25.

I can determine filter factor with the #25 but have no idea with the infra-red filter. Any ideas??

 

[charjohncarter]

I can't help you with the IR filter, but I use EV/ISO 40 with the red 25, almost no IR, but this is what I want:

You will have to go to Flickr and fish though the photos to see if anyone has given f stop and shutter speeds.

http://www.flickr.com/groups/388363@N24/pool/tags/hoyar72/