Review: MOD 54 – 4×5 film processing spiral by David Tatnall

Review: MOD 54 – 4×5 film processing spiral by David Tatnall

The MOD 54 is a plastic spiral that can hold up to six sheets of 4 x 5 film designed to fit a Paterson Super System 4 Tank, Model PTP 116 (one litre capacity).

The system was designed by Irish photographer Morgan O’Donovan.


The MOD54 is loaded with film emulsion side facing in; this is achieved by lining up the film notches with grooves in the spiral. I found some practice is required to get the feel of how to load the film successfully.

Once six sheets of film are loaded, the spiral is then placed into the Paterson tank (this is the tank that holds either three 135 spirals or two 120 spirals) and processed in daylight as you would roll film, processing with inversion-type agitation method.

Testing the MOD54

I practiced loading the spiral with out of date film in daylight.

Doing this first with eyes closed until it could be done it four or five times in a row then in the dark helped. You will need to be able to feel that all six sheets are loaded correctly with your fingertips, and this will take a little practice.

When you can confidently load the film four or five times in a row without making a mistake, it’s time to do it with your exposed film in the dark. On the MOD54 website there is a video of film being loaded.


The MOD 54 spiral is a very cleverly designed and well-built unit. It will be extremely useful for large format photographers away from their darkrooms, and for those starting in large format who as yet don’t have a darkroom.

It will also be beneficial to photographers wanting to process 4×5 E6 and C41 who don’t have access to commercial labs.

The unit can easily be loaded in a Harrison Pup tent and at a pinch a large regular changing bag.

Once the loading technique is mastered loading six sheets of film takes very little time.

The film I tested was evenly and well developed.

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This article was written by

David Tatnall is an Australian fine art photographer & editor of View Camera Australia.

There are 7 comments for this article
    • David Tatnall Author at 10:57 pm

      Thank you Ellie. I’ve used this in workshops over the past few years. Once you get the hang of loading it is very simple to use. The results have been consistently good.

  1. Steve at 9:21 pm

    Hi David,
    I have just got back into 45 after some 25 years. I have processed in the past but now looking for a tank. Which do you feel is the easiest for someone getting back into the system this Mod45 or the SP445 that you have also reviewed. I don.t have access to full darkroom so need one that can be used in full daylight.

  2. David at 7:07 am

    I have a Paterson tank that could fit this, and a bunch of failed exposures that I could easily use to learn how to load it.

    Just wondering, apart from ease of loading, is there any other advantage to the Stearman SP-445 tank? Does the Stearman require less chemistry to develop the same amount of film?

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