Redscale

A colour negative carries an orange mask on its base. Load the film backwards and the light must pass through that mask before it reaches the emulsion, so the base of the film works as a deep orange filter.

The filter takes the blue layer out almost completely and most of the green with it. What returns is red, orange and amber in one narrow band, with contrast raised, the colour flattened to a single direction and the grain coarse from the lost speed.

Say the film is loaded backwards and the light goes through the base first. The phrase shot through the film base does more work than the word redscale on its own.

Name the band of colour: red, orange, amber and a little yellow, with no blue and no green anywhere. Then name two objects that prove it. The sky is orange and the leaves are brown or red.

Say the film lost two to three stops, so the shadows are deep and empty, the contrast is high and the grain is coarse. Ask for strong direct sun, because redscale in weak light gives back a dark muddy frame with nothing to look at.

Use it for a summer scene, a desert, a beach, a sunset, a car on an empty road, or anything that already leans warm.

Leave it alone on a portrait that needs true skin, and on any picture where a blue or a green carries the meaning. Both of those colours are gone.

Cross processing is the other reversal a photographer reaches for, and it is published in the cinema catalogue at /techniques/cinema/colour-grading/cross-process/. Cross processing swaps the chemistry and throws the colour in whatever direction the stock chooses. Redscale changes no chemistry at all. The film is simply the wrong way round, and the direction is always red.

Cinema publishes Colour Shift as its own entry at /techniques/cinema/. That entry moves a picture toward any hue you name. Redscale is one fixed shift with a physical cause, and it takes two stops of speed away with it.

LomoChrome Purple is a stock with a colour swap built into the emulsion, not a loading trick. It sends green to purple and leaves the rest of the picture readable. Redscale collapses the whole frame into one band.

Photographers have rolled redscale by hand since the 1990s, taping the leader to the spool the wrong way round inside a changing bag. Lomography has sold it as a finished stock since about 2010, in 35mm and 120, rated from 50 to 200 so the user can choose how deep the red goes. The look belongs to holiday frames and desert roads, where the sun is strong enough to pay the lost speed back.

The model returns a normal picture with a warm filter over it. Say blue and green are gone completely, and say the sky itself is orange.

The other failure is a bright clean frame. Say the film lost two to three stops, so the shadows are solid and empty and the grain is coarse.