Henry: Automatic Agitator for the Paterson Super System 4 Developing Tank

For the Paterson Super System 4 developing tank with the agitator that comes with it. Henry fits the two-reel 35mm tank. We’re still testing whether it reliably drives the larger tanks in the range.

• Motion: swings back and forth, constantly changing direction
• Speed: adjustable with a knob
• Power: rechargeable battery, charges via USB-C
• Indicator: LEDs show the charge level
• Housing material: engineering plastic
• Colour: black
• SKU: 1852

If you develop film in a Paterson tank, you know the routine: minutes of inverting, and the lid still drips. Henry takes the agitation off your hands. It sits on top of the tank, engages the agitator and keeps the reels moving until you switch it off. Our customers used the first version for black-and-white as well as C-41; for color film, the tank simply sits in a water bath with a temperature controller as usual.

We built the first version of Henry a few years ago and sold more than 100 of them, every single one wired by hand. The new version gets its own circuit board, a battery with a USB-C port and a knob for setting the speed. Henry is designed and assembled here in Würzburg.

Henry is still in development, and we’re currently testing the production boards. Sign up for the waiting list above and we’ll let you know as soon as Henry is available to order. We’ll announce what’s in the box when sales start; the first production run comes at the early-bird price.

We sold the first, hand-wired version on eBay from 2020 to 2023. The reviews below were left there by buyers of that first version; on eBay, only people who bought the item can leave a review. We’ve reproduced them word for word (just without the emojis). They refer to the first version, not the new Henry.

“A great helper for C41 color developing if you don’t have the money to invest in a Jobo processor. My first color negative development with it worked wonderfully.”
eBay buyer i***r, February 2022

“good item, great to be able to walk away while developing! battery indicator is helpful as are the switches to set agitation speeds. It goes back and forth instead of full revolutions.”
eBay buyer j***t, April 2023

“Went great, works very well, makes the job a lot easier, would buy again anytime, many thanks.”
eBay buyer d***6, January 2022

“Top! Nice to find film photography enthusiasts who make affordable alternatives to otherwise unaffordable prices! Thanks”
eBay buyer h***s, August 2021

“Fantastic! Highly recommended!”
eBay buyer m***t, March 2022

Is it enough to turn the agitator instead of inverting the tank?
Paterson themselves recommend turning the agitator only at the start and inverting the tank after that. Rotary processors such as Jobo’s, which keep the film moving without a break, show that continuous agitation with regular changes of direction also gives you even development. Henry reverses direction after every swing. Even so, we recommend running a test roll when you first start out.

Do I need to adjust my development times?
In most cases, yes. With continuous agitation, film develops more strongly than with inversions once a minute. For rotary processing, cutting the time by 10 to 15 percent is a common rule of thumb. The safest approach is a test roll with your own film and developer combination.

When can I buy Henry?
Once the circuit boards, the housing and what comes in the box are ready and have passed our tests. We’ll only announce a date when we know we can keep it; if you’re on the waiting list, we’ll send it to you by email.

An early Henry prototype in action: