The Analog Infrared Quick-Start Guide

The TL;DR

Follow these steps to get started and obtain great infrared analog photography with Rollei INFRARED 35mm film.

1. Get a 35mm camera with a built-in through the lens (TTL) light meter. Make sure it doesn’t use IR diodes in the film transport.
2. Get an infrared filter to fit your lens. I recommend a 720nm filter because it although it’s very dark red it can still be seen through to compose, it covers the most IR sensitive region of Rollei INFRARED film and produces nice IR effects.
3. Get at least three (3) rolls of Rollei INFRARED 400 film. The first is a test roll to get the correct ISO setting that takes into account your camera light meter, the IR filter and your lens combination. The second roll is to fine tune your ISO and developer combination; the third roll is the one you can be confident with and will know the images will turn out repeatably and consistently.
4. Load the camera with the first roll and set the meter to 400 ASA/ISO. Only open the plastic film canister in a dark room. Do NOT load or unload the camera in daylight or anywhere where there is infrared light including interior room light. Go into a dark closet or bathroom and close the door. The film base is clear, light pipes through the edge and travels deep into the roll, causing fogging.
5. Pick a day and time with good clear sky and bright sunlight, and a scene with heavy trees and grass. Golden and blue hours are BAD for infrared. The middle of the day when the sun is strongest is best. The scene needs to have large portions with direct sun shining on it, areas of shadow have little IR light shining on them and will be very dark. A scene with trees, grass and buildings/architecture can be a good subject to test with.
6. Put the filter on the lens and bracket exposures +2, +1, 0, -1 the indicated meter reading. These equate to 100, 200, 400 and 800 ISO. Take careful notes of the settings and the frame numbers. Note that shutter speeds will likely be slow, around 1/8 to 1/30 seconds. Use a tripod if you want, but since this is only exposure testing a bit of unsharpness due to camera shake is acceptable. (A wide angle lens can help minimise the effect.)
7. Process the film in the recommended developer for the recommended time, temperature and agitation method. Unload the camera in darkness. FOLLOW THE DEVELOPING INSTRUCTIONS CAREFULLY so the results can be consistent and repeatable.
8. Take a look at the negatives and match the frame numbers with the exposure notes to work out which frames are the +2, +1, 0, -1 exposures.]
9. Look at the shadow detail: identify the frame in the bracket set that has details visible, even if they are thin. Hopefully they will all be the same frame in the bracket. If they are consistently the 0 frames then rate the film at 400 ISO. If the +1 frames are better, rate the film at 200 ISO; if +2 frames are better use 100 ISO. If some frames at 400 are good and some at 200 are good, rate the film at 200. If they are all too thin then expose another test roll with the meter at 100 ISO.
10. Scan or print the negatives from the best exposed frames. If shadow detail is good but highlights are blown out (and cannot be salvaged in post) reduce the development time by 10%. If the negatives lack contrast, increase development time by 10%. If decreasing development time, reduce the ISO by 1/3 or 1/2 a stop.
11. Set your camera to the new film ISO rating and go out and shoot the second test roll, this time not bracketing. Develop the film using the corrected time if necessary.
12. Examine the negatives for exposure and development: they should be pretty easy to scan and print. If necessary adjust ISO or development time.
13. For your third roll you’ll the correct ISO and developing time mot use for your camera and filter, and have a good idea of how the final IR images will appear.

The gallery below was made using Rollei INFRARED 400 film with a Canon EOS 600 and EF 20mm f2.8 USM lens, and a Camdiox IR720 filter. The location is a local park, the time was just after 9:00 am on a clear sunny Winters day in Sydney Australia.

The film was developed in Kodak HC-110 1+31 for 5 minutes at 20C as recommended by Rollei in this data sheet. Shutter speeds were often slow ranging from 1/8 to 1/30 seconds using apertures from f4 to f8. The camera was handheld and some images show camera movement, but hey it’s a test roll!

Based on the results the rating of 400 ISO and standard developing time are producing good images.

The negatives were scanned using a Plustek 8100 in SilverFast 9.0 without a lot of effort put into tweaking levels or curves. Leaves and grass shows a strong infrared Wood Effect; blue sky is darkened and clouds are enhanced.

Parts of the scene in shadow (not in direct sunlight) have very little IR shining on them, and appear very dark in IR images. The negatives have quite a bit of detail in these very dark regions, but lightening them in post changes the tonality of the image and reduces the appearance of the IR effect significantly.

Included in the gallery are two full colour images (taken on a phone) and their matching image made on IR film to give an indication of how the scenes look to the naked eye.

Introduction

Very nice infrared images can easily be made with with infrared film that’s available today, particularly Rollei INFRARED 400 which is available in 35mm, 120 and 4×5 sheet film. This article looks at 35mm, but a later article will look at 4×5 sheet film.

The “Golden Age” of analog infrared ended when the production of special purpose infrared films like Kodak Ektachrome Professional Infrared/EIR, Kodak High Speed Infrared HSIE and Efke IR820 black and white films ceased. Efke IR820 ended production in 2012, Kodak HSIE in 2007.

The remaining available film stocks available today — ILFORD SFX and Rollei INFRARED — have extended red sensitivity that includes the near infrared spectrum. These films can show the Wood Effect is used with appropriate filtration.

Let’s start with what we can expect from infrared images: the Wood Effect.

The Wood Effect

The Wood Effect is named after Robert W. Wood who discovered the effect, not because trees (ie, wood) look different in infrared (even though they do). The Wood Effect is where leaves and grass appear much brighter (white) in infrared than they do in visible light or on normal b+_w film. The effect is produced because healthy green leaves and grass strongly reflect infrared light. Our eyes cannot see infrared, so the effect is surprising and unexpected and leads to a dreamlike or “other world” images.

The things to remember about infrared photography are:

• the biggest and best source of infrared light outdoors is the sun on a clear day
• direct sunlight contains a lot of infrared light; anything in shadow (not in direct sunlight) has little or no infrared light shining on it
• healthy green leaves and grass strongly reflect infrared so these will appear very light or white in the image
• blue sky contains little infrared light so it appears quite dark in images; sunlit clouds in the sky reflect a lot of infrared, so blue sky becomes darker and clouds become lighter; sometimes thin clouds seem to appear from nowhere
• water absorbs infrared so lakes and ponds appear dark
• most other materials like wood, concrete and earth aren’t particularly strong reflectors or absorbers of infrared, so they appear fairly normal in the image
• some things reflect or absorb infrared in unexpected ways unrelated to their visible appearance: paint and clothing can change tone; some flowers have patterns that appear only in infrared; human skin can sometimes appear milky or glow

A Bit About The Light Spectrum

References to the “visible light spectrum” refer to light the human eye can see. Other animals can see light that is invisible to humans. Light is measured by its wavelength in nanometers, abbreviated to nm. The human-visible spectrum ranges from 380nm (deep blue or violet) to 750nm (deep red).

Light shorter than 380nm is called ultraviolet or UV; light longer than 750nm (red) is called infrared or IR. We can’t see UV or IR light but some birds, reptiles, insects, frogs and mammals can.

A Bit About Filters

Filters for infrared photography are usually marked with the wavelength they start blocking light: 680nm, 720nm, 760nm, 850nm or 950nm are common.

Remembering that we can see light down to 750nm a 680nm filter will transmit quite a lot of visible red light and longer infrared light, this will make it easy to see through; a 720nm filter will transmit only deep red light and longer infrared light and will be harder to see through; a 760nm filter will block all visible light and only transmit infrared light and cannot be seen through. The 850nm and 950nm filters are also visually opaque, they will also block some of the shorter infrared wavelengths as well.

A Bit About Film Sensitivity

Like the human eye, film also has a limited light spectrum. Early photographic materials were only sensitive to UV and blue light. It was discovered that adding dyes to the film extended the sensitivity to green light — orthochromatic films — and later to red light — panchromatic films. Almost all general purpose camera films available today are panchromatic. (The dyes used in early panchromatic films made them over-sensitive to UV and blue light, requiring the use of yellow filters; panchromatic films available today don’t have the problem.)

Dyes were discovered that extended sensitivity even further: films with sensitivity to about 900nm are (or were) called “infrared” while films that were sensitive to about 780nm have “extended red sensitivity.”

Unfortunately no films that extend into the longer infrared (notably Kodak High Speed Infrared HSIE or Efke Infrared IR820) are currently being made, the only films available have extended red sensitivity (regardless of how they are named or what’s written on the box). These films have just enough infrared sensitivity to see the Wood Effect with the right choice of filter and exposure: ILFORD SFX 200 and Rollei INFRARED 400.

Results with Rollei INFRARED 400 35mm

The photographs below were made with Rollei INFRARED 35mm film with a Canon EOS 630 camera with an EF 20mm USM lens (more on this lens choice below). The film cartridge is DX-Coded to 400 ISO and that was the default setting for the light meter. I used a Camdiox IR720 filter: I’m specific about the brand because I have purchased a couple of 720nm infrared filters and the amount of visible (deep red) light they transmit differs noticeably.