Review: SP-445 compact developing tank by David Tatnall

Review: SP-445 compact developing tank by David Tatnall

This new compact 4 x 5 developing system is a welcome addition to large format photography. Designed by Timothy Gilbert a US engineer and photographer who wanted to come up with an efficient economical and easy to use developing tank system for 4 x 5 film processing. He succeeded!

The production of the tank was funded by a successful Kickstarter project. It’s gone through many prototypes, a great deal of testing and it came onto the market in August 2016.

Manufactured in China out of ABS plastic it’s an upright tank capable of processing four sheets of 4 x 5 film. Approximately 200 mm high, 170 mm wide and 35 mm deep it weighs around 300 grams. The system uses 475 ml of solution.

The tank lid has two openings; a Vent and an Inlet/Outlet. The tank lid is held in place on the tank and made light tight by an ‘industrial strength’ O-ring. Inside the tank there are three light baffles and two film holders, the light baffles are only removed for cleaning and drying the tank.

The film holders have a series of notches along the long sides to hold the film. The film holders are removed from the tank, and then in total darkness two sheets of film are loaded in each and then returned to the tank, the tank lid returned and lights turned back on.


I tested this system using FP4+ film and Xtol developer. The instructions that come with the tank and several videos on the web site explain in great detail how to load the holders and how to fill and empty the tank, very straightforward.

I practiced loading the film holders with spent film. Loading the film into the tank film holders is as easy as loading conventional 4 x 5 film holders.

The loaded holders are placed into slots in the tank. The tank lid has an alignment lug that must match one on the tank, once again very easy to do. When the lid is on the tank is light tight and lights can be turned on.

For pouring solutions in and out, both the vent and inlet/outlet lids are removed. After filling the tank with 475 ml of developer, I tapped the tank to remove air bubbles, replaced the vent and inlet/outlet lids, and began agitation by four inversions every thirty seconds. Holding both the tank lid and the tank while agitating or emptying the tank feels best.

After processing I washed the film with water directly from the tap at a gentle rate for 15 minutes followed by a wetting agent. The washed tank and holders didn’t take long to air dry.


The negatives I produced with the system were evenly and well developed. A very straightforward and easy to use tank system.


Being designed by an engineer who is also a photographer has meant this developing tank system actually does what its meant to do – process 4 x 5 sheet film easily, efficiently and well.

It’s a great new method of processing sheet film. It is very easy to load and can be easily loaded in a changing bag.

I can see this system being a great benefit for those starting out in large format photography and who don’t have access to a darkroom and for large format photographers to use ‘on the road’. It’ll be great for large format photography workshops as well as E6 and C41 processing.

Some experimentation with development times and agitation cycles may be necessary to match results from other developing methods. However using the four inversions every thirty seconds method is a very good starting point. The negatives I produced are technically good.

This will be a great system for those who use stand development too.

Timothy Gilbert needs to be congratulated for his foresight and perseverance in making this very good new method of developing 4 x 5 sheet film.

The SP-445 is available from Stearman Press.

Neither David Tatnall nor View Camera Australia received any compensation for writing this review.

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David Tatnall is a Melbourne based fine art photographer.

There are 4 comments for this article
  1. Donald Stark at 2:49 am

    One of my favorite design features of the SP445 is that if you slightly squeeze the tank before tightening the caps, it doesn’t leak the chemistry!
    The most recent film holders have also been redesigned to allow better flow of the chemistry around the film.

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