How to shoot Ilford SFX 200 the most effectively?

Perry Way · Feb 24, 2023

Hello everyone, looking for advice from shooters of Ilford SFX 200.

I'm just now hopping back into analog world after over a decade and plan on using some Ilford SFX 200 film in a pinhole camera deep in the forest. I want the lightening or highlighting of the forest greenery which adds a lot of interest, and the darkening of skies seems pretty neato too. So, I bought a camera (RSS 6x9 F - f meaning filter ring) and on the Ilford film datasheet it shows a table of filter colors. Prior to reading the datasheet I read online from many people that I should use a Red 25a, so I bought one. Now I look at the datasheet and see there's a 29 "Deep Red" and a 89B "Very Deep Red" and I'm wondering if maybe I should have selected one of them instead because I plan to shoot forest scenes while backpacking and want the definition of greens to be prominent. Ilford says "The redder the filter, the more dramatic the effect" so is this a go big or go home moment where I should acquire the deepest reddest filter possible to get the effect I want?

The 25 filter has a filter factor of 2.8 but -1.5 stops
The 29 filter has a filter factor of 3 but -1.66 stops
The 89 filter has a filter factor of 16 but wow, it's -4 stops. On pinhole this could be either disaster (fogging of the wind rustling the leaves) or sublime (mountain creek)

pentaxuser · Feb 24, 2023

The 89B is the equivalent of the R72 which is the filter for a film like SFX 200 if you want an infrared effect of white foliage. The other filters will help to produce black skies but not really produce the full IR effect

Are you hoping to get this look when you say you want the definitions of greens to be prominent? If you only want to lighten green foliage to make it different from the brown bark of the trees then a green filter will achieve this

If you are seeking the IR effect then you are right that the long exposure will cause motion to show on the film as blur

pentaxuser

Perry Way · Feb 24, 2023

pentaxuser said:
The 89B is the equivalent of the R72 which is the filter for a film like SFX 200 if you want an infrared effect of white foliage. The other filters will help to produce black skies but not really produce the full IR effect

Are you hoping to get this look when you say you want the definitions of greens to be prominent? If you only want to lighten green foliage to make it different from the brown bark of the trees then a green filter will achieve this

If you are seeking the IR effect then you are right that the long exposure will cause motion to show on the film as blur

pentaxuser

What I'm hoping to get is more definition meaning you can see the individual leaves distinctly. Increasing the contrast of shadowing.

I'm experienced with pinhole and know the rules but I enjoy it the most. Ideally I find the best way to shoot on the trail.

I'm getting the opinion that 25 won't do the trick. So I'll be looking for the darker one next and try both out, then get an objective result

Sirius Glass · Feb 24, 2023

Perry Way said:
What I'm hoping to get is more definition meaning you can see the individual leaves distinctly. Increasing the contrast of shadowing.

I'm experienced with pinhole and know the rules but I enjoy it the most. Ideally I find the best way to shoot on the trail.

I'm getting the opinion that 25 won't do the trick. So I'll be looking for the darker one next and try both out, then get an objective result

Red25 should work well I use it often with Rollei IR 400 film. the R25 and 720 [89] are respectively stronger. Start with the R25.

Andrew O'Neill · Feb 24, 2023

The last time I used it I shot it at EI 6 with a 720 filter.

Perry Way · Feb 24, 2023

Sirius Glass said:
Red25 should work well I use it often with Rollei IR 400 film. the R25 and 720 [89] are respectively stronger. Start with the R25.

Thank you. I will try that first, and see how it goes.

retina_restoration · Feb 24, 2023

I did some pinhole work with SFX many years ago, using the R72 filter, and exposures were in the range of 8-15 minutes in blazing bright sunlight.

Perry Way · Feb 24, 2023

retina_restoration said:
I did some pinhole work with SFX many years ago, using the R72 filter, and exposures were in the range of 8-15 minutes in blazing bright sunlight.

wow, that's not a very good reciprocity index I would say. what was your f-stop and focal distance and size of the negative?

MattKing · Feb 24, 2023

It is important to understand that the purpose of the R72 filter is to block out almost all the visible light.
And it is equally important to understand that the remaining films with sensitivity into the near infrared - such as Ilford SFX - are mostly sensitive to visible light, and aren't all that sensitive into the infrared.

retina_restoration · Feb 24, 2023

Perry Way said:
wow, that's not a very good reciprocity index I would say. what was your f-stop and focal distance and size of the negative?

That was using the Zero Image 6x9 camera (120 roll film format, 6x9cm negative), which has an aperture of f235 (supposedly)

Perry Way · Feb 24, 2023

retina_restoration said:
That was using the Zero Image 6x9 camera (120 roll film format, 6x9cm negative), which has an aperture of f235 (supposedly)

Ahh I skimmed over the Zero Image part. Yeah their 6x9's are in my opinion not wide enough and why I overlooked them this time around. Exposure time increases with focal distance and in a pinhole it's really a big difference. I just bought an RSS 6x9 which has about I think 22 mm focal length so that's real real wide, and distance closer to film so exposure time much less because f stop less. I prefer wide angle though it fits my shooting style the most, especially with pinhole.

Maris · Feb 24, 2023

I shoot Ilford SFX 200 behind a #25 red filter at E.I. = 25 and at E.I. = 6 behind a IR720 filter.
The reciprocity failure correction number given by Ilford is 1.43. This means for measured exposure times more than a couple of seconds
take that measured exposure time to the power 1.43 to get the corrected time.
Good luck.

Perry Way · Feb 24, 2023

MattKing said:
It is important to understand that the purpose of the R72 filter is to block out almost all the visible light.
And it is equally important to understand that the remaining films with sensitivity into the near infrared - such as Ilford SFX - are mostly sensitive to visible light, and aren't all that sensitive into the infrared.

I was wondering if that was the case actually. Not from experience or anything but because of the masking effect of colored filters. Yeah that makes sense. Well, I will stay away from that Zeiss Ikon IR filter that would fit my non-folding Zeiss Ikon Continas. Look for another R25, or close, but I can tell you that there aren't any Zeiss ones which I would like since I'm establishing a collection of good condition shooters.

Perry Way · Feb 24, 2023

Maris said:
I shoot Ilford SFX 200 behind a #25 red filter at E.I. = 25 and at E.I. = 6 behind a IR720 filter.
The reciprocity failure correction number given by Ilford is 1.43. This means for measured exposure times more than a couple of seconds
take that measured exposure time to the power 1.43 to get the corrected time.
Good luck.

Oh thanks so much! I was looking for this. I got the datasheet but if it's in there I didn't spot it. Where do you get this information from? I want to get it for all their films. I used to have this information years ago but when I sold my Zero Image pinhole I sold it with all this historically proven charts for exposure times for all configurations of my camera. I had every Ilford, every Kodak, every Adox, every Foma and Bergger BFP 200.

Patrick Robert James · Feb 24, 2023

Ilford SFX is a near infrared film, not a true infrared film if my memory serves me correctly. I used to shoot it with a Red 25 and I would dead recon the exposures, not rely on the cameras meter. An ISO of 25 sounds about right with the Red 25. Been a loooong time since I've used it though.

MattKing · Feb 24, 2023

This might assist:
https://www.photrio.com/forum/threads/choices-for-ir-film.174757/#post-2273526

retina_restoration · Feb 25, 2023

Perry Way said:
Ahh I skimmed over the Zero Image part. Yeah their 6x9's are in my opinion not wide enough and why I overlooked them this time around. Exposure time increases with focal distance and in a pinhole it's really a big difference. I just bought an RSS 6x9 which has about I think 22 mm focal length so that's real real wide, and distance closer to film so exposure time much less because f stop less. I prefer wide angle though it fits my shooting style the most, especially with pinhole.

I found that the difference in results between a standard dark red #25 and an R72 filter used with either SFX or Rollei IR films was minimal. So, I would suggest that if you pursue using SFX with a filter that you just got with a #25 red. It will make it much easier to get good exposures, especially if you choose a pinhole device. With a regular (lensed) camera, the #25 red VS the R72 will be the difference between being able to make hand-held exposures, VS using a tripod.

pentaxuser · Feb 25, 2023

retina_restoration said:
I found that the difference in results between a standard dark red #25 and an R72 filter used with either SFX or Rollei IR films was minimal.

Does that mean that you found the normal red filter i.e. the 25 to give you the full or at least nearly full "Wood effect" of white foliage with that wispy look or was it just a lightening of green foliage and black skies in full sun conditions? The latter was all I could ever manage with a red 25

Thanks

pentaxuser

retina_restoration · Feb 25, 2023

pentaxuser said:
Does that mean that you found the normal red filter i.e. the 25 to give you the full or at least nearly full "Wood effect" of white foliage with that wispy look or was it just a lightening of green foliage and black skies in full sun conditions? The latter was all I could ever manage with a red 25

Thanks

pentaxuser

To achieve the most pronounced "wood effect", the amount of exposure is more critical than your choice of filters. As others have explained, overexposure increases the "dreamy" IR effects you can get from SFX. Its not quite as easy to achieve as it is with the Rollei IR, but very close.

pentaxuser · Feb 25, 2023

retina_restoration said:
To achieve the most pronounced "wood effect", the amount of exposure is more critical than your choice of filters. As others have explained, overexposure increases the "dreamy" IR effects you can get from SFX. Its not quite as easy to achieve as it is with the Rollei IR, but very close.

Thanks So instead of using the filter factor of the 25 say 3 stops or an EI of 25 in the case of SFX 200, you overexpose by reducing the EI to what speed, 12 or 6. or lower? In effect if this works as well as an R72 filter then what you are doing is using the same speed as you would with an R72 but in this case with a red 25?

Clearly this saves the expense of an R72 but I had always thought that overexposure per se wasn't enough as the R72 literally blocked wavelengths of light that the red 25 just wasn't capable of

So does the R72 do anything at all that the red 25 does not provided it is used at the correct number of stops?

Thanks

pentaxuser

Perry Way · Feb 25, 2023

pentaxuser said:
Thanks So instead of using the filter factor of the 25 say 3 stops or an EI of 25 in the case of SFX 200, you overexpose by reducing the EI to what speed, 12 or 6. or lower? In effect if this works as well as an R72 filter then what you are doing is using the same speed as you would with an R72 but in this case with a red 25?

Clearly this saves the expense of an R72 but I had always thought that overexposure per se wasn't enough as the R72 literally blocked wavelengths of light that the red 25 just wasn't capable of

So does the R72 do anything at all that the red 25 does not provided it is used at the correct number of stops?

Thanks

pentaxuser

I'm so glad I asked this question. This is getting to be interesting reading all your responses. So happy I get to learn from those who already have approached this topic. Save me a lot of time!

Perry Way · Feb 25, 2023

retina_restoration said:
To achieve the most pronounced "wood effect", the amount of exposure is more critical than your choice of filters. As others have explained, overexposure increases the "dreamy" IR effects you can get from SFX. Its not quite as easy to achieve as it is with the Rollei IR, but very close.

Very interesting. I am totally game to try but.. I'm struggling with the concept of over exposing making the highlights more highlight in the greenery. How does that work? Is it because maybe the red sensitive emulsion is much thicker and if you over expose it you get that effect? I've not worked with these filters and film before. To my way of thinking overexposing leads to darker always. Can you help educate me so I can understand? Thanks!

Sirius Glass · Feb 25, 2023

pentaxuser said:
Thanks So instead of using the filter factor of the 25 say 3 stops or an EI of 25 in the case of SFX 200, you overexpose by reducing the EI to what speed, 12 or 6. or lower? In effect if this works as well as an R72 filter then what you are doing is using the same speed as you would with an R72 but in this case with a red 25?

Clearly this saves the expense of an R72 but I had always thought that overexposure per se wasn't enough as the R72 literally blocked wavelengths of light that the red 25 just wasn't capable of

So does the R72 do anything at all that the red 25 does not provided it is used at the correct number of stops?

Thanks

pentaxuser

I believe that the 720 filter is mostly beyond the reach of the SFX 200 and you will be disappointed with the results. Look on line for tests of the various IR films with the same scene with different filters. Also look at the data sheet below for SFX 200 and its spectrum response.

pentaxuser · Feb 25, 2023

Sirius Glass said:
I believe that the 720 filter is mostly beyond the reach of the SFX 200 and you will be disappointed with the results. Look on line for tests of the various IR films with the same scene with different filters. Also look at the data sheet below for SFX 200 and its spectrum response.

View attachment 330610

Sirius, I am pretty sure that those shots I have seen with the R72 on SFX have been the only ones to capture the "Wood effect" which I cannot recall seeing captured by the red 25 and certainly I have never managed the "Wood effect" with a red 25.

However retina restoration suggested that you get close to the full IR effect with overexposing with a red 25 which I have never done so I have asked some questions

What would be interesting are pics of retina's restoration use of SFX with overexposure

pentaxuser

Helge · Feb 25, 2023

Patrick Robert James said:
Ilford SFX is a near infrared film, not a true infrared film if my memory serves me correctly. I used to shoot it with a Red 25 and I would dead recon the exposures, not rely on the cameras meter. An ISO of 25 sounds about right with the Red 25. Been a loooong time since I've used it though.

There is a misunderstanding that near infrared is not true infrared.
It absolutely is.
Anything over 700 nm is well and truly infrared.
IR is just such a large band up to microwaves, that it has to be split up into near, medium and far IR.
Wood effect starts right around 700 and Rayleigh effect has planed off about as much as it will there too.

How to shoot Ilford SFX 200 the most effectively?

Perry Way

pentaxuser

Perry Way

Sirius Glass

Andrew O'Neill

Moderator

Perry Way

retina_restoration

Perry Way

MattKing

Moderator

retina_restoration

Perry Way

Maris

Perry Way

Perry Way

Patrick Robert James

MattKing

Moderator

retina_restoration

pentaxuser

retina_restoration

pentaxuser

Perry Way

Perry Way

Sirius Glass

pentaxuser

Helge

How to shoot Ilford SFX 200 the most effectively?

Moderator

Moderator

Moderator

Privacy & Transparency

Privacy & Transparency