Redscale Film

How Does It Work and How to Make One Yourself

5 min read by

This mini-guide explains how redscale film works and how to make your own redscale film. All you need is scissors, tape, and a dark room (most bathrooms will do).

Flipped (redscale) Lomography Color Negative 400 on Diana Mini.

My wife introduced me to practical film photography through Lomography six years ago when we were just starting to date. Before then, I thought of it as an idealistic, almost unattainable way of capturing light: I saw movies, huge silver and palladium prints at the galleries — it felt too rich for my blood.

Lomography’s nonchalant attitude towards the medium made it seem much more approachable and opened up my mind to some experimentation.

Lomography does not make shooting film exactly thrifty, however. Their toy cameras typically sell for over $50 — and they do break. Film itself costs money. I was not yet ready to drop wads of cash on this new hobby, but there were some things that I really wanted to try. Redscale film being one of them.

Eventually, my curiosity led me to figure out how to produce my own redscale film and save a few bucks. What’s more, this approach is applicable to practically any C-41 emulsion, which opens up a whole world of untapped redscale potential!

Flipped (redscale) Lomography Color Negative 400 on Diana Mini (in square mode) with light leaks.

How redscale film works.

The reason the colours shift towards the red is layers.

Photographic film is made of multiple layers, three of which are typically responsible for sensing the red, green, and blue hues of the visible spectrum. Those layers vary in their sensitivity to the light: blue is the least sensitive, and red is the most.

1. Film base; 2. Adhesive layer; 3. Red light sensitive layer; 4. Green light sensitive layer; 5. Yellow filter; 6. Blue light sensitive layer; 7. UV Filter; 8. Protective layer; 9. Visible light (when shot as regular, non-red scale film).

On film, those layers are arranged with the blue-sensitive one facing towards the lens — thus receiving most of the light. The green-sensitive layer is next, receiving less light. The red-sensitive layer is all the way at the back, receiving the least amount of light.

Manufacturers pay particular care to balance the layers’ sensitivities to create an accurate colour representation of reality. This is done by cranking up the red’s sensitivity to match the blue layer’s output. The result is, ideally, a naturally-looking picture.

Flipping those layers by having red facing towards the lens instead of the blue turns the colour balance on its head. Because the red layer is most sensitive to light, it becomes the most noticeable colour in the picture. Blue hues, which’ layer is being the least sensitive and furthest from the lens, become rare, almost entirely limited to light leaks and strong over-exposures.


How to make your own redscale film.

The technique involves unrolling your film in the dark, cutting it, flipping it along the long edge, and taping it back. This is not a particularly difficult task, but it does become tricky when you can not see.

Practice your movements before getting started. Particularly remembering whether you flipped the film or not and taping it back together. You want the film taped neatly and securely after you cut it. The best way is to wrap the tape just once around the film. You will need to make sure that no extra bits are hanging off the edges where you taped your film back together — otherwise, it will get stuck in the canister.

Start with a cheap film first. There’s a chance that things won’t work out; it’s best not to ruin your CineStill.

Prepare your darkroom. You don’t need a professional space, just a bathroom with the lights off. Do pay attention to any light coming into the room; I had to place a towel over the gaps in the door frame. Essentially, it needs to be pitch-black. Keep your tape and scissors handy so that you don’t have to look for them.

Lights off.

In complete darkness, unroll your entire 35mm cassette and cut it about two inches away from the canister. To be safe, you can give it even more slack. As you do this, keep your film and your film canisters still — you must be aware of their position and orientation for the next step.

How to make redscale film out of any 35mm colour negative.

Carefully flip the film along the long edge and tape it back together as you practiced earlier: neatly, securely, and with no bits hanging off the sides.

This is the trickiest part. Your taping must be done really well in absolute darkness, and you also need to remember to flip the film only once and not lose the canister in the process. Once you’ve verified (by feel) that all is in good order, go ahead and wind the film back into the canister. Make sure to leave about five inches of film hanging outside so that you can load it into your camera.

Lights on.

Now you can verify that you’ve successfully flipped your film with your eyes by looking at the leader tip. You may need to reshape it with your scissors so that you can load it into your camera.

And that’s it! Remember to experiment with exposure — more light means less redness and vice-visa.

Flipped (redscale) Lomography Color Negative 400 on Diana Mini.

All images in this article are shot with Diana Mini.