Using SFX

[EcoLeica]

ok broke down again and thought i would give Ilford SFX a go again. Last time i used my leica IIIc with nice results but nothing i would call 'infarred'. With that in mind ive decided to use my newly acquired Nikon FE with cokin red filter. I havent used a SLR for a while so i would like to know if what i read in the meter with the red filter is the correct exposure or do i have to compensate. Another question is what do you rate SFX at?....i know it says 200asa but after my last results maybe i should use it at a faster speed such as 100 or fifty?

Any advice would be greatful

 

[mr_phillip]

To get the IR effects with SFX you really need to use a proper IR filter, or a super-deep red filter as a minimum. I use the Hoya R72 and find that gives a nice IR effect without getting too extreme. Are you using Ilford's Cokin "P" SFX filter, or just a standard Cokin red? If it's the latter you're likely to be disappointed again.

Re the rating issue, I agree that 200asa is pushing it a bit – my guess has always been that Ilford rate the film a little optimistically knowing that it's going to be used with filters that effectively rob the film of 5-6 stops (so even at its box speed, by the time I add the Hoya filter I'm metering at 6asa). I've seen nice results with the film rated at 100asa, but in all but the brightest light that's likely to result in exposure-times of the tripod-dependent variety.

My fave shot I've taken with this film was taken on my Canon P with a 28mm Ultron and developed in DD-X 1+4 for 10 minutes:

 

[EcoLeica]

cheers for the help.....just read the cokin book and it said that if i combine my standard red with their polariser filter i should get a more dramatic effect.

Excuse my ignorance but my TTL metering through the filters should give me the right exposure right? or do i have to use exposure compensations?

 

[mr_phillip]

Excuse my ignorance but my TTL metering through the filters should give me the right exposure right? or do i have to use exposure compensations?

Actually, they'll almost certainly be out by a stop. Light meters place a disproportionate emphasis on light in the red part of the spectrum, with the consequence that dark red filters have the effect of 'tricking' the meter into thinking there's more light than there actually is (since the light that reaches the meter is purely red).

In practice this almost always means that the 'correct' reading will actually be one stop more than the meter shows. As you're not totally familiar with either the camera in question of with the filters you'll be using, it'd likely be wisest to bracket both with the meter, and one stop over.

 

[mr_phillip]

Hmmm, fair point – in theory you're totally right. In practice though I've always found that, after bracketing as described, the one-stop-over shots were always the better exposed of the two (the shot above was metered using a Sekonic handheld meter set to 6asa, so doesn't count). It was so consistent that I gave up bracketing with this film ages ago and just treat it as I would a panchromatic film.

I'm guessing (and this is totally a guess) that maybe SFX's extended sensitivity to light in the infrared/near-infrared frequencies doesn't translate totally into over-sensitivity to light in the visible red spectrum? It's a tricky film fer sure 🙂

 

[mr_phillip]

Yeah, which is partly why I've always stayed away from proper IR films in favor of SFX – it's definitely easier to live with if you don't need the more extreme IR effects. Plus it helps that, here in the UK at least, SFX can be found for way less money than any of the full-on IR stuff.

 

[EcoLeica]

thank you both of you for your advice, im off today to give it another go, fingers cross

 

[Dogman]

I've used SFX in medium format with the Hoya R72 filter and gotten nice IR effects. I used a handheld meter set for the box speed and bracketed widely. Best results for outdoor photos were obtained in early spring when foliage displayed more IR effects. With a standard 25 or 29 red filter, there was little IR effect, if any. You really need to use an IR filter for this film to give you that effect. The R72 filter is essentially opaque and filters out most visible light.

I've also shot it in 35mm with regular filters and without filters and it looked like standard film--a bit grainy however. SFX can be loaded outside a darkroom. I've loaded it into the camera in shaded bright light with no fogging whatsoever. I haven't used it several years--I think it was discontinued for a while.

 

[rich815]

I do not think your standard red filter and the polarizer is going to give you the "infra-red" look you want. You absolutely need the R72 or equivalent.