Need Help with B/W filter for Mamiya M645

[Slick60]

Hello,

I’m planning on using my Mamiya M645 and a roll of Ilford SFX 200 with a red 25A filter and a polarizing filter. The red causes a loss of 3 stops and the polarizer 2, so if used together will it be a loss of 5? Also, does the red filter go on the lens first or does the polarizer?

Thanks,

Slick60

 

[cramej]

Correct on the exposure compensation.

For the order, doesn't matter although it will be easier to adjust the polarizer if it's on the front. With 2 filters and the polarizer being a bit thicker, you will need to watch for vignetting unless they are oversized.

 

[MattKing]

I doubt you will see any Wood effect from that combination. When I've used SFX 200 for IR work, I've needed an R72 filter.
But assuming that you are just looking for the effect of those filters on regular films, I would put any multicoated filter on the outside.
5 stops would be a good place to start. And I would use it outside, and meter with an incident meter.

 

[Slick60]

Correct on the exposure compensation.

For the order, doesn't matter although it will be easier to adjust the polarizer if it's on the front. With 2 filters and the polarizer being a bit thicker, you will need to watch for vignetting unless they are oversized.

Thank you very much for your help. Good point about having the polarizer on the front for easy adjustment.

I can tolerate a bit of vignetting, but I can crop it out with my enlarger. Sometimes vignetting looks good. I guess I’ll just have to experiment.

Thanks again,

Slick60

 

[Slick60]

I doubt you will see any Wood effect from that combination. When I've used SFX 200 for IR work, I've needed an R72 filter.
But assuming that you are just looking for the effect of those filters on regular films, I would put any multicoated filter on the outside.
5 stops would be a good place to start. And I would use it outside, and meter with an incident meter.

I’ve heard that Ilford SFX isn’t a true IR film, so I didn’t pick up any IR-rated filters like the R72. But I did notice that it looks much better with a red 25A versus without, and the polarizer adds to the dramatic sky.

Good to know about the meter. Thanks again for your help.

Slick60

 

[MattKing]

Actually, there is a fair amount of potential for SFX and Wood effect:
[URL="https://www.photrio.com/forum/threads/choices-for-ir-film.174757/#post-2273526"]Choices for IR film?[/URL]

 

[MattKing]

This thread may be of interest as well:
https://www.photrio.com/forum/threads/r72-and-polariser-question.160157/#post-2082771

 

[M Carter]

I've really come to like Rollei IR400; it's a decent "normal" film, reacts really well to a deep red filter, and you can do very much "IR"/wood shots with the stuff. It does seem to need more exposure than most 400 films though.