ZET ROPER-BLACKMAN
ZET
CAMERAS
Above you will find version 14 in all its glory, but it did not start that way with its familiar look and plausible functionality. so Please do read on.
Like most good side projects, the life consuming kind, I cannot pinpoint exactly when I began mulling over a scratch built camera. But the point at which it became attainable was at the start of 2026 when realising 3d printed parts were a worthy stand in for routed aluminium mechanisms. This meant that mechanisms which otherwise couldn't be prototyped during a lunchbreak and iterated on in the evenings were brought into the realm of the hobbyist. Because the point is that at any kind of hobby level it is pointless to compete with the watchmaking that is mechanical cameras. Even with a decent cnc, sharp corners and teeth require so much post processing that the project threatens to go unfinished. That or it requires perfect design first time which I cannot possibly provide. But printing, yes the resolution is limited, yes it wont last forever, does it need to?
Extra challenges to needlessly implement.
1: Where possible, do not consult the internet for reference.
2: No electronics.
Point one sent me down some bizzare windscreen wiper like shutter designs, spring loaded curtains, a host of bizzare, complicated, fruitless avenues which warmed up the old brain.
But such foolery led comfortably to version 6, the first plausible, first printable edition. And with it was cemented a pivotal but adjustable design decision going forwards, the choice of an M42 lens mount. Picked for its inherent printability, they are less available, and more expensive, but the flipside to this is how easy it is to adjust flange focal distance errors, which there would be many.
Version 6 used two wiping shutters, holes cut in blade like segments, that'd expose and block the frame in sequence, the second triggered by the first. In real life this resulted in an exposure somewhere around 1/30th of a second. Photographers amongst you, (which I am not) are aware that that is far too slow really for handheld. But I'll learn that soon enough.
VERSION 6
Its design, which you get a hint of here, is heart like in a way, but stems from a smooth loft between the offset perimeter of the mechanism and the necessary shape of the boring side; the film presenting side. It is, therefore, an accident and I don't think I could have made it look so interesting on purpose.
This model contains a few machined parts which I tried to avoid going forwards for their time consumption. At this point I already suspected this would not be the final form, and as such spending time making unique metal components was exhaustive.
The body was printed in four parts, 'light sealed' (it was not light sealed) with a liberal coating of spray paint.
That there are images at all was all the inspiration I needed to carry on now that V6 was starting to limp.
The multiple exposure of the bright ghost like image was the tell-tale of failure, a stripped grub screw ruining what was an entire day out at the beach with my brother.
LEAF SHUTTERS. VERSION 7 ONWARDS
A number of problems presented themselves. In order of importance:
1:Too slow a shutter speed
2:Bulky
3:Terrible to use
Addressing these backwards....
General unusability was owed to several points. Firstly,I ran out of time to implement a shot counter. When winding on the film I relied on the diameter of the takeup spool being exactly 36mm in circumference. But of course the diameter changed as more film was wound on, and a compounding error grew.
Also, the viewfinder sucked. It was essentially a guessing game where you were aiming because, by (bad) design, it pointed dead straight and dead ahead. Being 50mm offset from the lense meant it was impossible to take a picture of anything with much certainty.
Thirdly the mechanism took up far too much space. Much streamlining was needed. The various reset plungers got caught everywhere.
And despite the shutter working and being light tight once painted, there wasn't really much optimisation that could be done. Doubling the spring force or halfing the mass would only get me to a measly 1/60 and that just felt like patching over a poor design with stronger springs. Plus I was already having trouble with the shutters bouncing, so would need to damp those. It really didn't have any upside, but included a whole lot of faff.
One solution could easily wipe out two of my problems, and that was a leaf shutter. Same springs, a few hours, immediately at 1/60th.
OPTIMISATION
Brilliant, I hear you thinking. Finished, completed it, stick that on a body and be done with it... But no. I mean forgive me just momentarily. This shutter has, arbitrarily, 5 leaves.
OK? I hear you asking.
But wouldnt it be so much better with 6! Think of the symmetry!!
I mean maybe-
And while were there why not also make it adjustable! More than 1 shutter speed! Variable, infinitely variable with different delays, a slow speed setting and a high speed option and-
Well lets fast forwards a month and I will show where this road goes.
The first step in this was to create a 6 leaf shutter. For some reason, this was much harder than a five leaf shutter and required a lot of iteration.6 leaf variants were both smaller, but also required similar length and thickness than 5 leaf variants. This resulted in much less room for error, and a thinner overlap than other designs.
Then, defining the diameter of the rings to operate the leaves, the rest of the mechanism could be drawn. The animation below then shows the basic working principle of the design.
2 spring loaded disks are released in sequence, the first opens the leaves, and the second closes them. The reset allows both of them to turn together, to return them to the first position but preventing the shutter from opening again.
From the three blade proof of concept, the five blade imperfection, to now a robust 6 leaf variant, I lost myself for far too long fiddling around with various tactics for slowing down, mechanically, 3d printedly, things happening too fast to observe blinking. Counterweights were cumbersome, geartrains too slow, too low quality. Basically all I can say by the end of version 4, was that I needed to decouple the trigger from the shutter open ring.
Up until now, like with the bladed shutters, cams acting on the rings which carried the six leaves were triggering the mechanism to close the shutter. This cost energy, time, and was an arms race.
More force needed for faster actuation -> More friction needed to release mechanism -> Too much energy used -> Mech too slow -> Need bigger springs.
Again, this might be fixable balancing springs and adding graphite, but this will never exist in perfect settings, it is printed after all. It needs to be reliable enough that this -> isn't a worry.
Essentially I needed a signal mechanism and two trigger mechanisms. That way, speeding up the trigger was not costing the quick acting mechanisms any energy.
This spring loaded cam, complete with two seperate tracks, allows for smooth and repeatable staggering of the shutter release. THEORETICALLY, to slow down the shutter speed this simply needs to move slower. Which in my mind was enough, and by this point a problem for another day. For now, a single shutter speed will do. This mechanism will reliably hit 1/100th, some fine adjustment in ramp distance lets me fine tune the desired speed.
FIN?
Well, no.
Some stupid hand sketch that I fell in love with forced me to spend another two weeks designing this thing. Yes, I am frustrated by it, but only because it never worked. What a ridiculous object! How wonderful it could have been...
Complicated light seals, poor flange distance adjustment, a constricted film path with terrible tension. The dream died the moment I tried to assemble the prototype. I know it would have taken photo, but at what cost? How many light leaks, how frustrating to have the film jam. It wasn't meant to be, and so there died the dreams of a bizarre enclosure.
VERSION 14
With few remaining unknowns, I defeatedly retreated from the unusual and built version 14, a particularly normal looking thing. It is nice to end up at something vaguely recognisable, because surely that means I'm on the right track.
The disc on the front to make people say, hang on a minute? The stubborn dog leg that did nothing but add problems. It's still most definitely mine. Finished in light porous SLS, a satisfying beginning of a successful camera.
And some photos at the end taken on this camera. Three rolls in, still wrestling light leaks, but most of them are from behind so hopefully I can narrow it down soon enough and actually worry free use this out and about.