Ortho Litho film is a specialist film intended for use in lithographic and graphic art applications. Specifically, it is extremely low speed, extremely high contrast, and not sensitized to the color red and thus can be handled under a red safelight. These properties make it quite difficult to use for standard pictorial purposes, but with specialized developing processes, it is possible to “tame” this extremely wild film and produce very interesting and unique results. Almost all results here are using Arista Ortho Litho film custom cut into 120 format. I have also done some limited testing with Kodalith, Ultrafine ortho litho, and some other brand of ortho litho that I can’t find right now. The only real difference is that kodalith is slightly faster (maybe 1/2 stop) than all other brands and both kodalith and ultrafine has a different base material which is less transparent.

This document will be split into two sections. High speed and low speed processing. High speed is of course easier to shoot, but a bit harder to process and typically more grain. Low speed can achieve better control over contrast levels, has better over exposure latitude, and with fine to impossibly fine grain. Note I do not cover extremely high contrast development. I use this film high contrast sometimes for masking in the darkroom and Dektol at paper dilutions works well enough for this use, but if you truly need 100% black/white then you should use Lith A&B developer at proper dilutions etc.

Development By Inspection

Ortho Litho films can be safely developed by inspection with red safelight. In my tests with Arista Ortho Litho, the safelight needs to be rather dim, not shining directly on the film, and exposure should still be minimized, especially when using high speed processing methods. If you are using development by inspection, you should test your safelights using both high speed and low speed processing methods for the film. As long as it doesn’t fog within 10 minutes for either, you should be ok. Make sure to keep the development trays covered when not actively inspecting, and to minimize the time that you keep the film out. I use the red LED bulbs from “Ultra Bright LEDs”. I normally have an amber and red bulb with the red bulb strictly illuminating by reflection, and the amber bulb shining directly over my trays. I simply turn off the amber bulb when working with ortho litho film and have measured a safety margin of at least 20 minutes for low speed processing and 10 minutes for high speed.

Before developing solely by inspection, I also recommend testing out the process with a few sheets (even if “shot” by using an enlarger) so that you can know what to expect. Dim safelights can be quite misleading to how much density you actually have on the film.

High Speed Processing

The biggest problem preventing a truly higher film speed with ortho litho is that shadow detail drops very quickly from low density values to completely clear (dmin). By solving this problem, it’s possible to push the film’s speed quite significantly while maintaining reasonable contrast levels.

The best way I found to do this is to flash the film. This has the effect of bringing up the shadow values beyond the dmin threshold level so that some amount of detail will develop. The most common and arguably easiest way to do this is to put the film under an enlarger with no negative and expose it for a very small amount, such as f/22 for 2s. There is another method though.. but it’s not exactly… well, I’ve never seen anyone ever try it before, but , there is also a method of doing chemical flashing.

Flashing with light

This method is simple if you have a darkroom and are dealing with film sizes that your enlarger can accommodate. Despite popular belief and anecdotes, there is no difference between flashing before exposure and flashing after exposure. There are also some people who flash in-camera, by using some kind of diffuse material over the lens such as a simple tissue or something more elegant and pointing their camera to the sky with a very short exposure time. I recommend using an enlarger if possible for consistency, but either method can work well if you’re careful to calibrate it.

The basic process for enlarger flashing is to first figure out what works for your enlarger. Set your enlarger to a specific height. I recommend putting your enlarger to a level that you can cover the largest film size you intend to ever use, such as 8x10 or 11x14 (keep in mind you can use this for internegatives also!). Cut a test strip and simply put the film under the enlarger and do a test strip like you would with paper, doing masked 1s exposures at f/22 or something else rather dim. Put a small mark with a marker or something on each block exposed. Keep one exposure block completely unexposed and mark it, to act as a reference for dmin. Afterwards you can process the film in a standard paper developer like Dektol. Make sure to develop for quite a bit longer than normally, maybe 3-5m with Dektol. Stop and fix as usual and then inspect. Look for when the film just barely gets more grey, it may be quite subtle. Count the marks up and write down the exposure level, lens used, and height of the enlarger. You can now use this setting for all flashing needs with that film type! When I use this method, I simply flash the film just before developing.

Chemical Flashing (ie, PFS-4)

The enlarger method is great and fairly simple, but I had a big problem with it. It’s simply impossible to reliably and consistently expose large strips of film. This isn’t much problem for traditional sheet film sizes, but for 35mm or 120 formats it’s quite impractical. Using this film at high speeds with smaller formats is ideal for my style so that I can reliably go hand-held on a bright sunny day.

Through an absolutely incredible number of experiments and wasting probably 30 rolls of custom cut 120 film, I found a reliable, shelf-stable, and easy to acquire chemical mixture that will function in a way very similar to flashing. I named this solution PFS-4 “post flashing solution version 4”. The formula for this is extremely simple:

375ml hot (~40C) water

75ml of TEA (triethanolamine)

50g potassium bromide

2ml of 1% potassium iodide solution (optional, seems to make fogging slightly less likely)

Top up to 500ml with water

For yellow technical grade TEA: Dilute to 1+30 for use. Process for 2-3m for Arista Ortho Litho.

For clear photographic grade TEA: Dilute 1+15 for use. Process for 3-5m for Arista Ortho Litho at 70F with VIGOROUS agitation (especially in tank development). For tray development do NOT stack multiple sheets and ensure the film is emulsion side up. It also seems to be quite temperature sensitive. Rinse film well before to remove anti-halation layer, and rinse film well afterwards to avoid residual TEA causing pH changes in the developer.

If you show this to any film chemist, they’d say that this should effectively do nothing. There’s absolutely no literature to back up how this solution works. I don’t know how it works, I just stumbled upon it by accident. However, the results speak for themselves.