We've just received the new film holders for the SP-445. There are some pretty obvious modifications: 1. We added cutouts but left a narrow strip as a sheet separator. This allows for better chemical flow behind the film. 2. We removed the ridges on sheet separator. (Frankly, we debated even keeping the separator, we tested with and without and didn't see any difference.) In the end, we decided to leave it; if you don't like, it can be cut out in about a minute. 3. We also added a finger notch at the top; makes it easier to get...
Well, the prototypes just arrived. They look pretty good but will need some polishing to get ready for testing. Hopefully, we'll have results by Monday. As you can see, it's much bigger than the SP-445.
We're still getting the occasional question about the caps used on the SP-445. The question now: what do you do when you lose one? (Come on, admit it, you will lose one.) Sure, they are available on the website but that doesn't help you on a Sunday night when you're supposed to have pictures ready Monday morning. As we've said, it is a standard size: the industry calls it a 33/400 (33mm in diameter; not sure where the 400 came from). Here's what I found after a quick trip to our fridge and the local convenience store. Okay, the bottle...
We finally did it! Here are the details: https://www.kickstarter.com/projects/1653453089/sp-457-5x7-sheet-film-processing-system
A brief history: Let me try and make a really long story, somewhat shorter. The first prototypes were completely flat, had a solid groove on each edge to hold the film and did not have the finger at the bottom edge. They were also 3D printed and felt flimsy. The first change was to add the ridges: these reduced surface tension when removing the film and increased the flow behind the film. They also added stiffness. We then chopped up the solid grooves into "fingers". This improved flow but also made the mold much easier to manufacture. Last, we added...