Reveni Labs Dunkbot automated film processor

[Oren Grad]

Interesting contraption - in addition to 35/120, the design allows for 4x5 on "reels" like the MOD54 or B's 4x5:

https://www.kickstarter.com/projects/mattbechberger/dunkbot-affordable-automated-film-processor/

Disclaimer: I have no connection to Reveni Labs other than having purchased a couple of their products.

[paulbarden]

Not enough information about how film is agitated in this system. This seems like a lazy person's toy and nothing more.

[Tin Can]

I quit all Kickstarter long ago

Along with new ideas

I will plod my way

As long as

I CAN

[Oren Grad]

Not enough information about how film is agitated in this system.

"The developing tank is partially lifted and lowered to agitate the chemicals during a processing step. The number of agitations and frequency can be customized, allowing for stand or semi-stand developing."

The obvious question is whether this is enough to consistently deliver even development.

[Alan9940]

The obvious question is whether this is enough to consistently deliver even development.

I'm not Matt's target market for this since I own a Jobo, but in reviewing the short intro video I'd be concerned about:

1. It looks like chemicals feed into the tank from the bottom through some sort of light-trapping holes/slots. I'd like to know the exact flow inside the tank. Why? When I first started developing LF film with tanks & hangers, I'd get surge marks from the holes along the bottom of the hanger because I was agitating too fast. Might this be an issue with this device?

2. All I've seen of the agitation cycle is an up/down motion. How 'bout a twist, too? As Oren said, is this up/down only motion enough to provide even development?

[mattthegamer463]

I'm not Matt's target market for this since I own a Jobo, but in reviewing the short intro video I'd be concerned about:

1. It looks like chemicals feed into the tank from the bottom through some sort of light-trapping holes/slots. I'd like to know the exact flow inside the tank. Why? When I first started developing LF film with tanks & hangers, I'd get surge marks from the holes along the bottom of the hanger because I was agitating too fast. Might this be an issue with this device?

2. All I've seen of the agitation cycle is an up/down motion. How 'bout a twist, too? As Oren said, is this up/down only motion enough to provide even development?

Hi Alan, the holes in the bottom trap are swept 90 degrees about the centre of the tank, so there is a circular flow when the tank fills. There is a pretty large total hole area, to make sure the tank fills and drains quickly, so the flow is not high pressure. It's only forced in by the gravity of the raised fluid in the pot so it doesn't have a lot of pushing power.

[lassethomas]

Really, that’s the most over-engineered solution I’ve seen for a problem that’s already solved.

[mattthegamer463]

Really, that’s the most over-engineered solution I’ve seen for a problem that’s already solved.

Why? Sweeping the holes increased their length enough to provide light-blocking properties, and the part is 3D printed, so complexity is free.

[Oren Grad]

Matt, thanks for stopping by to respond to comments.

[Oren Grad]

Really, that’s the most over-engineered solution I’ve seen for a problem that’s already solved.

Lasse, if you're referring to the device as a whole, I'm not aware of any other similarly automated device at anything close to that price point.

[lassethomas]

Why? Sweeping the holes increased their length enough to provide light-blocking properties, and the part is 3D printed, so complexity is free.

Oh, sorry I didn't mean to comment just the solution for the bottom trap. Have no input regarding that detail.
I meant the whole solution.

To me it looks like too many part, motors, switches, mechanical complexity, six heaters, complex software and so on. To many points of failure.
Compare this to a Jobo-like solution that has one motor, one pump and one heater.
You wouldn't have to drain and fill during processing of course, like in the Jobo, but you still have to do it before and after processing if I understand correctly.
Also I don't understand how you rinse. I at least would like to do so under running water for at least 5 minutes.

Well, if you are into standing and semi standing this could have an edge perhaps.

[lassethomas]

Lasse, if you're referring to the device as a whole, I'm not aware of any other similarly automated device at anything close to that price point.

Well, maybe you are right Oren.
Perhaps it's just me having a bad day.

[Michael R]

My advice to the creator would be to do very thorough testing of development uniformity (B&W And colour) in order to evaluate the quality of the processing, as well as what film sizes to recommend. Test all formats and don’t assume anything. For example, if it gives good 35mm results don’t assume it will give good 4x5 results just because it fits in the tank. Agitation does not scale simply, and theorizing alone does not work. Test, adjust, test, adjust, test...