Efke infrared

[radchad]

I posted a previous post about infrared and you all helped me find this film. i was wondering how you would use this film in the 4x5 size? focusing, exposing with fall off etc.
thanks
chad webb photography
www.chadwebbphotography.com

[Scott Rosenberg]

chad, i shoot it like any other film... with the addition of an IR filter of course

seriously, i don't handle it differently in any way.

[Ralph Barker]

IR light has a different wavelength than the visible spectrum. So, in theory, the focus should be adjusted a bit for precise focus. I forget the exact amount, but it's a small fraction of the focal lenth of the lens being used. In practical terms, if you are shooting at "normal" distances out doors, and use a typical LF aperture (around f/22 or so), no focus adjustment is usually required. You'll have enough DOF to cover the theoretical adjustment. Thus, I'd suggest focusing normally, add the IR filter, and then expose.

Note, too, that the amount of IR light varies with latitude, time of year, and time of day. As such, you'll need to bracket /experiment to determine the proper exposure for your area. My approach is to meter normally, and then apply the IR adjustment to arrive at the actual exposure.

[al olson]

Chad,

First of all, your choice of filter is critical. A Wratten A (#25) is not sufficient to obtain the Wood effect (like it was with HIE) because the film is far more sensitive in the visible spectrum than in the infrared. The result will appear similar to panchromatic film. The vegetation is medium gray, not white and the skies are not very dark.

Best is a filter that blocks everything below 720nm. Also because the infrared range only goes to 820nm, the infrared filters above 720nm are impractical. I use a Hoya R72 or a Cokin 007 for this film.

Because these filters do not pass visible light you must do your composition with the filter off the camera and then replace it for your exposure. Of course your other choice is to leave the filter on your lens and compose with a separate viewfinder.

I usually meter the film at an EI of 1.5. I add a couple of minutes to the recommended development time because the negative image is so thin that it barely looks usable. However I find that it, surprisingly, makes a very acceptable print with a good contrast range.

As Ralph says, use small apertures to accommodate the shift in focus. I also often times tweak (very small change) the focus slightly closer which also seems to help. With an EI of 1.5 and small aperture your shutter speed is going to be very long. This makes landscape work very tricky because the vegetation will have motion blur at the slightest breeze.

I hope this is the kind of information you are looking for.

[John O'Connell]

The old rule of thumb for focus adjustment when using infrared film (for distant subjects) was to focus closer by 1/400 of the focal length of the lens---but this was with Kodak HIE. The need for focus adjustment is lower with modern infrared films.

[SAShruby]

Will Red 29 be enough for this film to achieve typical infrared pictures or do I have to go with infrared filter?

[jetcode]

I believe that with the current Infrared offerings most certainly Rollei Infrared Red 25 or 29 will not be suitable. I used Red 25 with HIE and it worked as expected. When I used Red 25 with Rollei not much in the way of Infrared made it to the film. I suspect the Infrared sensitivity is overwhelmed by visible light spectra which is why these films are rated in the low ISO's.

[al olson]

Joe,
You are absolutely correct. I have found that when using MACO/Efke/Rollei it is necessary to use an infrared filter that cuts off the visual light below 720nm. For this I use either a Hoya R72 or a Cokin 007. Because of this it is necessary to use an EI of 1.5, maybe a 2 or 3 will work if the IR light is strong.

Peter,
I have never used a #29 with these films. However, the cutoff is far enough to the edge of the visual that you might get a partial Wood Effect. I am sure that it would darken your skies. The only 29 I have fits my Kodak Retina iiic and it worked well with Kodak's HIE films.

[SAShruby]

Thanks for the answers. I also found a gelatin wratten #87. It cuts off light at 800nm (100 transmittance, however it has about 50% transmittance at 750nm. Would this filter be better than Red 29?

Thanks.

[al olson]

Peter,

I would be interested in hearing of your results with the #87. The Efke sensitivity in the IR region is so low that I would be discouraged from trying it.

Although I have never tried the #29 on anything except Kodak HIE, I would surmise that the cutoff is close enough to the edge of the visual spectrum that you might get some modest IR results.