How to shoot Ilford SFX 200 the most effectively?

[Helge]

I'm an AmeriCAN This intrigues me, this idea. I have had other silly ideas and as a result created an unencryptable file/data transfering system that is totally secure. I just haven't sold it yet. But if I stay in programming much longer I will. It's already to go past Alpha, and now sorta Beta except for user interface. Someone told me Perry leave it alone, you'll wrack your brain, more misery, don't do it, just rely on the same algorithms that the NSA invented

Anyway, I am looking into Infrared detectors. Photo-detectors is the broad name applied. Now this is stuff I can't do personally but I know engineers that would be able to take the detector and measure the radiant IR wherever you point it. Then based on that reading come up with a method for applying that raw data against some experimentation in order to develop an IR-reciprocity-index. Make sense? Doesn't take much energy to do my research. This place here looks interesting, but I'm only a software engineer, I don't understand these measurements to know if any one of their detectors could be used for this purpose.

Infrared Detector Manufacturer

I’d be interested in a real IR meter too. As said, it shouldn’t be very difficult to take apart a silicon diode meter and remove the IR attenuation filter and insert a band pass filter.
Not super easy either though.
Problem is, just normal metering and using experience on top works well enough most of the time to make a dedicated meter stay a dream.

 

[Perry Way]

I’d be interested in a real IR meter too. As said, it shouldn’t be very difficult to take apart a silicon diode meter and remove the IR attenuation filter and insert a band pass filter.
Not super easy either though.
Problem is, just normal metering and using experience on top works well enough most of the time to make a dedicated meter stay a dream.

Turns out there's a meter already made. Making use of it for IR film photography will require some education though as it's a scientific instrument.

LaserCheck (RoHS)

Handheld low power meter, silicon photodiode, measure to 1W with switchable attenuator, spectral compensation.

coherentinc.my.site.com

I discovered this because of a period of my career I consulted for a video surveillance company building surveillance systems for them and IR lighting is really involved in that industry, so I started poking around on search engines and found this article. It's intended for videography, not photography, and they have sensors that are more capable of measuring IR than say Ilford SFX which is why they can get footage even in pitch black.

How to Measure IR Illumination

Using IR for night time surveillance is a popular choice. The added non visible light can improve image quality when ambient street or visible lighting...

ipvm.com

I've got a number of things I need to do before I get to this IR pinhole project, so I did the investigation to this point and putting it on the shelf so I can attend to some plans for my section hike later this month. I do intend on returning and doing more research and I'll just keep providing any more information that I gather along the way. If anyone else decides to add to this, please feel free. Those of us who are motivated to come up with a more or less reliable system of predicting the behavior of any specific scene using instruments can make this whole concept less of a mystery and more of a system or procedure, much like most photographers just whip out a light meter to set their cameras, perhaps one day we can whip out an IR light meter and set our cameras and know we're going to be darn near close and well within the respectable film latitude as some films are better suited than others.

 

[MattKing]

perhaps one day we can whip out an IR light meter and set our cameras and know we're going to be darn near close and well within the respectable film latitude as some films are better suited than others.

The interesting question is, for pictorial photography, will you actually need a spot meter?

 

[retina_restoration]

The interesting question is, for pictorial photography, will you actually need a spot meter?

For the making of actual photographs, on film - no, you don't need a precision IR measuring instrument. That's overkill.

 

[pbromaghin]

I'm struggling with the concept of over exposing making the highlights more highlight in the greenery. How does that work?

This is because all those beautiful colors we see in the autumn have been there all along, but were masked by the overwhelming amount of green before the chlorophyll went away. The filters remove it for you. I was wondering from your original post whether you might want to use a conventional B&W film with a green filter. It depends on how much lightening you're looking for.

 

[Helge]

For the making of actual photographs, on film - no, you don't need a precision IR measuring instrument. That's overkill.

Some situations can surprise. A forrest for example can be a lot more IR dense than you’d expect with the shade. Maybe because the foliage reflects IR. A field of grass can be very hard to judge.
Human subjects vary a lot, depending on a number of factors.
Because IR is inherently contrasty and IR film is often contrasty on top is easy to miss exposure completely in these situations.

Turns out there's a meter already made. Making use of it for IR film photography will require some education though as it's a scientific instrument.

LaserCheck (RoHS)

Handheld low power meter, silicon photodiode, measure to 1W with switchable attenuator, spectral compensation.

coherentinc.my.site.com

I discovered this because of a period of my career I consulted for a video surveillance company building surveillance systems for them and IR lighting is really involved in that industry, so I started poking around on search engines and found this article. It's intended for videography, not photography, and they have sensors that are more capable of measuring IR than say Ilford SFX which is why they can get footage even in pitch black.

How to Measure IR Illumination

Using IR for night time surveillance is a popular choice. The added non visible light can improve image quality when ambient street or visible lighting...

ipvm.com

I've got a number of things I need to do before I get to this IR pinhole project, so I did the investigation to this point and putting it on the shelf so I can attend to some plans for my section hike later this month. I do intend on returning and doing more research and I'll just keep providing any more information that I gather along the way. If anyone else decides to add to this, please feel free. Those of us who are motivated to come up with a more or less reliable system of predicting the behavior of any specific scene using instruments can make this whole concept less of a mystery and more of a system or procedure, much like most photographers just whip out a light meter to set their cameras, perhaps one day we can whip out an IR light meter and set our cameras and know we're going to be darn near close and well within the respectable film latitude as some films are better suited than others.

Seems it’s an instrument meant for measuring laser power. I’d be very surprised if it worked for IR photography.

One strategy I’ve employed when I have time, is to photograph the scene with a phone through the relevant filter and measure with a light meter app afterwards.
Not perfect, but results in a visible assessment of the scene that isn’t too far off from then actual film photo.
The EXIF data isn’t much use.

 

[Sirius Glass]

I’d be interested in a real IR meter too. As said, it shouldn’t be very difficult to take apart a silicon diode meter and remove the IR attenuation filter and insert a band pass filter.
Not super easy either though.
Problem is, just normal metering and using experience on top works well enough most of the time to make a dedicated meter stay a dream.

I have had good success with internal and external reflectance meters for HIE and Rollei IR 400, both at ISO 400 and then adjusted for the red filter used.

 

[Helge]

I have had good success with internal and external reflectance meters for HIE and Rollei IR 400, both at ISO 400 and then adjusted for the red filter used.

Sure, me too. You need to meter.
But the discrepancy between shade and direct sun is unpredictable and doesn’t go with what the meter was made for.
A colour meter might be a good alternative to a real IR meter.
If the light is warm there is a likelyhood that it will contain IR. Foliage is still a problem though because the Woods effect onset quite abruptly at 700nm.
I had good results by letting an N/F80 meter through an R72. Even AF works, although it’s slow and wonky.

 

[bluechromis]

Some situations can surprise. A forrest for example can be a lot more IR dense than you’d expect with the shade. Maybe because the foliage reflects IR. A field of grass can be very hard to judge.
Human subjects vary a lot, depending on a number of factors.
Because IR is inherently contrasty and IR film is often contrasty on top is easy to miss exposure completely in these situations.



Seems it’s an instrument meant for measuring laser power. I’d be very surprised if it worked for IR photography.

One strategy I’ve employed when I have time, is to photograph the scene with a phone through the relevant filter and measure with a light meter app afterwards.
Not perfect, but results in a visible assessment of the scene that isn’t too far off from then actual film photo.
The EXIF data isn’t much use.

View attachment 331036

I will have to try this.

 

[bluechromis]

I have had good success with internal and external reflectance meters for HIE and Rollei IR 400, both at ISO 400 and then adjusted for the red filter used.

I agree. I know that conventional meters are said to not accurately measure IR light. My practice is to meter with the camera without the filter or with a handheld meter and then reduce the exposure by a factor for the IR filter, e.g., six stops. I find this usually works well enough. I bracket the exposures as insurance, but typically the original plan for the exposure in okay. It could work to adjust t the camera ISO setting for the effective EI for IR, e. g. EI 12. Then I don't have to do filter factor adjustment. I'm just afraid I would forget to reset when doing non-IR photos.

Using super dark filters like an R72 or a black ND is a case where an SLR can be less convenient. Every time you setup for a new scene you have remove the filter because you can't see through it. So you are constantly taking the filter on and off. That's one reason I got a TLR. They do have those hinged adapters that swing the filter on and off the lens though. Rectangular filters might be easier as well.

I was given the advice to on each IR roll (session) to shoot at least one image not using the filter to use as a reference. IR images are so peculiar it can be hard to judge from them if development etc. was on target.

 

[bluechromis]

Because IR exposures are typically long, one thing to watch out for is motion blur in the scene. Sometimes we want motion blur, e. g., streaked water in streams. But with things like nearby foliage waving around in the wind it may not look so good.

 

[Sirius Glass]

Sure, me too. You need to meter.
But the discrepancy between shade and direct sun is unpredictable and doesn’t go with what the meter was made for.
A colour meter might be a good alternative to a real IR meter.
If the light is warm there is a likelyhood that it will contain IR. Foliage is still a problem through because the Woods effect onset quite abruptly at 700nm.
I had good results by letting an N/F80 meter through an R72. Even AF works, although it’s slow and wonky.

I am looking for the Wood Effect, not using the Zone System to get every bit of shadow detail possible. I use Red23, Red25, R3d29 and 720 filters.

 

[Helge]

I am looking for the Wood Effect, not using the Zone System to get every bit of shadow detail possible. I use Red23, Red25, R3d29 and 720 filters.

You’ll get a hint of Woods with R29, but only full effect with R72.
Again even if you refuse it, visible light polarizers do actually work with the lower NIR,
and they work wonderfully for: Blackening the sky out completely, bringing reflections down on water, metal and finally to tone down Woods effect.

 

[Sirius Glass]

You’ll get a hint of Woods with R29, but only full effect with R72.
Again even if you refuse it, visible light polarizers do actually work with the lower NIR,
and they work wonderfully for: Blackening the sky out completely, bringing reflections down on water, metal and finally to tone down Woods effect.

Polarizers could be used, but why use a tool which is not as effective. One could also use a lens cap, but then there would not be any Woods Effect.

 

[Helge]

Polarizers could be used, but why use a tool which is not as effective. One could also use a lens cap, but then there would not be any Woods Effect.

Not as effective? It’s works as it does on visible spectrum.
Simple as that.

 

[Sirius Glass]

Not as effective? It’s works as it does on visible spectrum.
Simple as that.

A basis engineering maxum: If it works, use it.

 

[super_claret]

I’m interested in experimenting with Ilford SFX 120 in my Fuji GF670 rangefinder. Am I correct in assuming that I can focus as normal if using without filters but if I use an IR filter, the focus point will change? What about a red or orange filter?
How do I go about accurate focussing, as there is no infra red marking on the lens? I know I’ll more than likely be using smaller apertures anyway, so probably not important? Should I just use f22 and focus at infinity?

Also, if I’m using a red filter which needs an additional 3 stops exposure, I can just set the meter to ISO 25 And develop normally?

 

[Sirius Glass]

I’m interested in experimenting with Ilford SFX 120 in my Fuji GF670 rangefinder. Am I correct in assuming that I can focus as normal if using without filters but if I use an IR filter, the focus point will change? What about a red or orange filter?
How do I go about accurate focussing, as there is no infra red marking on the lens? I know I’ll more than likely be using smaller apertures anyway, so probably not important? Should I just use f22 and focus at infinity?

Also, if I’m using a red filter which needs an additional 3 stops exposure, I can just set the meter to ISO 25 And develop normally?

Use box speed and a red filter. Take the light reading and adjust for the filter factor. I found that bright sun on the subject with the sun behind me always works well. At this wavelength IR, one does not need to adjust the focus.

Welcome to APUG Photrio!!​

 

[MattKing]

As Sirius says, the film isn't sensitive to light that is far enough into infra-red to make it necessary to adjust the focus.
A red filter will give you a sort of "infra-red look". A 720nm filter will give you much more Wood Effect, while requiring much more exposure in order to compensate for the almost opaque filter.
When you take most of the visual spectrum light away with the 720nm filter, the contrast and Subject Luminance Range is changed a fair bit. Normal development tends to work best for me, but I tend to use this film in high overcast conditions - not bright sun.
This post may be useful for you:
https://www.photrio.com/forum/threads/choices-for-ir-film.174757/#post-2273526

 

[Helge]

No focus change. You are just out of the visible spectrum.
SFX should be rated around ISO 10 with a 720 filter. 25 with a deep red R29 sounds about right.

Use a tripod for optimal sharpness with such a large format.

Try a polarizer held in front of the lens. But for that you will really need a tripod.

 

[Andrew O'Neill]

I’m interested in experimenting with Ilford SFX 120 in my Fuji GF670 rangefinder. Am I correct in assuming that I can focus as normal if using without filters but if I use an IR filter, the focus point will change? What about a red or orange filter?
How do I go about accurate focussing, as there is no infra red marking on the lens? I know I’ll more than likely be using smaller apertures anyway, so probably not important? Should I just use f22 and focus at infinity?

Also, if I’m using a red filter which needs an additional 3 stops exposure, I can just set the meter to ISO 25 And develop normally?

You don't need to worry about focus compensation with any IR films on the market today. Even when I used HIE I didn't bother because I never used anything stronger than a #25 filter. If I used the 87C, then I would compensate, but that filter was overkill with that marvelous film. Just add the filter factor. Focus through the red filter (such as #25, or #29). If you want more open shadows or Wood effect, expose more. I rate SFX at EI 100, and always use a 720 filter (+5 stops more exposure) to EI 3. If you use a 720, you will have to compose and focus, before putting on the filter. SFX is a nice film. I would use it more often if it were available in 4x5

 

[Sirius Glass]

As Sirius says, the film isn't sensitive to light that is far enough into infra-red to make it necessary to adjust the focus.
A red filter will give you a sort of "infra-red look". A 720nm filter will give you much more Wood Effect, while requiring much more exposure in order to compensate for the almost opaque filter.
When you take most of the visual spectrum light away with the 720nm filter, the contrast and Subject Luminance Range is changed a fair bit. Normal development tends to work best for me, but I tend to use this film in high overcast conditions - not bright sun.
This post may be useful for you:
https://www.photrio.com/forum/threads/choices-for-ir-film.174757/#post-2273526

That should work nicely too. I was keeping is simple to start.

 

[super_claret]

Thank you for the info. Would the same apply to Rollei Infrared 400 (except the ISO rating). Just seen the price of Ilford SFX in the UK and it’s nearly twice the price of Rollei Infrared. Think I might try the Rollei first to experiment.

 

[Helge]

Thank you for the info. Would the same apply to Rollei Infrared 400 (except the ISO rating). Just seen the price of Ilford SFX in the UK and it’s nearly twice the price of Rollei Infrared. Think I might try the Rollei first to experiment.

I prefer IR400, but it’s not 400. Closer to 160 probably. But the rating with a 720 filter is about the same. IE 10. Plenty fast for handheld in full sun.
It’s contrastier and finer grained than SFX.
Use a 40.5mm filter in the hood.
This is probably good: https://www.ebay.com/itm/4038950455...De7EmQ6S-q&var=&widget_ver=artemis&media=COPY
Never had problems with Chinese IR filters.

 

[super_claret]

I prefer IR400, but it’s not 400. Closer to 160 probably. But the rating with a 720 filter is about the same. IE 10. Plenty fast for handheld in full sun.
It’s contrastier and finer grained than SFX.
Use a 40.5mm filter in the hood.
This is probably good: https://www.ebay.com/itm/4038950455...De7EmQ6S-q&var=&widget_ver=artemis&media=COPY
Never had problems with Chinese IR filters.

Thank you. I’ve been reading more about the Rollei 400 IR and it seems most people prefer it over the Ilford SFX. I’ve ordered some and am looking forward to using it.

If I’m using the film unfiltered, I rate it at 160 ISO and when using the IR72 filter, I rate at 10 ISO, is that correct? I’d normally meter for the shadows and develop for the highlights, does this still apply with IR film?