Build Test Outline


#1

Hi all,

Time to start building. I made a very basic platform out of acrylic and am ready to start putting our ideas to the test - building the next Kinograph one section at a time and testing all our options along the way.

I’m going to be starting with the drivetrain (take up motor, capstan tests, torque vs. drag, etc.) since everything depends on that working well.

Here’s the order of tests I think would be productive, and allows for spreading out major expenditures:

PHASE 1 - MOVE THE FILM
Goal = get film moving reliably through the machine

a. Drivetrain (what motors, where they go, how they work with each
other and the system overall)
b. Film path (roller placement, etc)
c. Gate design


PHASE 2 - IMAGE CAPTURE
Goal = get reliable results with high quality images for a range of budgets

a. Frame detection/registration (speed, accuracy)
b. Cameras/optics (arange of options tested. hopefully by multiple people following
along)
c. Lighting (adjustable, flash, etc)


PHASE 3 - POST WORKFLOW
Goal = efficient and cheap tools for making accessible video files

a. test available software tools
b. discuss functionality of custom software where needed
c. memory management, cloud options, etc.


PHASE 4 - SOUND
Goal = usable sound for accessibility, not preservation purposes (although that would be nice)

a. AEO Sound test
b. alternative software solutions (custom build?)
c. hardware solutions (slit scan, reverse engineer existing designs)


Ideally I have some people building in parallel that can do more tests and verify my results. This should help us move quicker.

We can also be doing some of these phases in parallel once we all have a working drivetrain/gate/path.

All suggestions and comments welcome as we embark on this. Let me know what you are all thinking! In the meantime, I 'm going to start collecting all comments on the drivetrain we’ve had so far so I can build a list of possible solutions we want to test. That will lead to a list of materials to buy. And I do like shopping for gear…

Matthew


Build Phase 1, section a - Motor Assembly
#2

Sounds great! I like the idea of parallel testing with multiple participants. So, how does all this begin? Any specs of the various options? I think once we get a base blueprint/schematic, we’ll find out what tweaks it needs.

I’d be interested in helping out with the budget-level 8mm option. Also, I have access to various 3D printers and laser cutters through my library’s makerspace. If we needed to print/cut parts, I could possibly do that and send to people at cost. As for 3D printers, they have a makerbot replicator 2, a resin printer, and a couple others. I forget exactly what laser cutter they have, as I believe it can cut 1/4" or less wood & acrylic, but it’s not powerful enough for metal cutting.


#3

Will you be using the same drivetrain for all the variants(8,16,35), just different rollers & guides?


#4

I am a newcomer to this forum but an old ( as in age ) and old ( long term ) user of 16mm cameras and film and in the digital cinema realm, own and operate a SI2K camera.

I am curious if anyone has used a Steenbeck four-plate flatbed editor as a mechanical base for a 16mm film scanner. The optical path of a Steenbeck does not come up to resolution requirements. It uses a multifaceted prism instead of a shutter and intermittent film transport. It is inherently gentle on film. I have wondered if using a flash source through the existing optical path might improve and stabilise the image enough for a basic telecine or scanner.

There has been a SI2K film scan / telecine system built as a one-off however I have not been able to get hold of any technical details. It was apparently an LED flash scan system. The SI2K uses a Altasens 2/3" 2K sensor.

Any clues on either of these systems will be much appreciated.


#5

Welcome, @agus35monk! Old timers and 'long-term’ers are just what we need.

The Steenbeck is an interesting idea, although hard to find and quite bulky. If anyone has access, I’d be most immediately interested in the motor systems and any related feedback mechanisms for gauging tension and adjusting speed on the take-up side.

Anyone have a Steenbeck just…laying around? I’d be surprised but if anyone does they’ll probably end up here eventually.

M


#6

Good questions, @digitap. To be honest, I’m not sure how this will work. I figure I’ll attack the process in bite-sized chunks so that it’s easy for people to weigh-in at frequent intervals and keep up with the build without it getting too complicted (i.e. many steps that take more than a weekend to do). HOpefully this will give people a chance to try their version of my latest test.

I’ll give a concrete example. I’m uploading an update video right now (will post as soon as it’s ready) that is only focused on how to mount the reel on its platform. It’s limited in scope (how to attach the shaft to a flat plane) - and people could go in several directions on their own without a large investment in time and hardware (less than 3 parts, less than $50). They could build the platform out of wood or metal, or try a different method of mounting the spindle.

IOW - there’s only focal point for this step. I hope every step will be that simple. This also serves another purpose, which is that it will be easy to go back and see where decisions were made. It’s analogous to how coders update their backups (or repos). They only add one feature at a time, and when it’s working, they save the state of the project before moving to the next feature. The features are always small so that if they break, they are easily fixed and do not affect the whole system.

So I guess we’ll just see how it all develops!


#7

I enquired because I do have a Steenbeck 4plate from older times. It isvery heavy. The motor is about the size of a large washing machine motor. The film transport out-feed and take-up relies on the weight of the platens and rolls or film or tape in each to achieve grip of a simple clutch of friction material and a metal disk.

The film transport itself is sprocketed rollers, each side of the “gate”. There is no intermittant movement but a sweeping scan of the passing frame via a multifacetted spinning prism. This introduces a sort of pulsing effect on the image which seems to stretch it slightly in a vertical direction as viewed.

The transport consists of two film paths, one for magnetic film for sound track and one for the image film. Each path is separately clutched to the drive motor which has a 24fps playback, a slower playback and a fast playback/fast-forward function.

Either film path might be adequate for moving film. Because the motor cab be clutched out, the transport could be advanced by another means.

When the screen box is taken off, the image can be projected and on a reflective screen, is adequately bright for video camera to record it. I imagine it might not be too difficult to rig some sort of aerial image arrangement to a compact camera.

This might require some surgery to the deck of the Steenbeck to accommodate the bulk of a video camera, something I am not so keen to do as the Steenbeck I prefer to remain as a viewing machine as well.


#8

Yes Agus35monk, I have converted a 16mm Steeny to a telecine machine, the prism causes too much image quality loss, so it needs to be removed.
We replaced the light source with a LED ‘flash’ based system so that you can freeze each image for capture as it flies past the gate.

A camera with lens is mounted in place of the mirror and hood setup, so it points directly at the film gate. You need a bright source as the gate is slightly curved, so a deep depth of field is required to get focus across the frame.

The image is incredibly stable, due to the great manufacturing on the Steenbeck. They are big and heavy though, I had one drop on me unloading it from the truck and I needed a lot of stitches in my leg!

It does require surgery to get the camera close enough to the film gate, but our Steenbeck is still used as a viewing machine, except it now feeds to a monitor instead of the old hooded screen, so it is a ‘digital steenbeck’ now.


#9

Thanks for that encouraging response. It is much appreciated. Is there any chance of an image of the “surgery” required. Did it require cutting into the actual transport module which fits into the wooden deck of the machine or just the wooden deck. Also how did you remove the prism. I am assuming you left the larger split roller which rotates around the prism.

From recall, this is what establishes the curved “gate”. It might be possible to add two rollers each side to straighten the film plane but that would introduce other issues like ripples in the film causing it to move off the focal plane and thus requiring a physical gate.

I am anxious not to do harm to that prism as they are pretty much irreplacable. For your flash trigger, what did you end up using for that. I was minded that I might have to mount a segmented disk on top of one of the driven sprockets with an optical or automotive hall-effect sensor for accurate timing.

I would like to use the SI2K mini camera head. I have a spare however the apparent resolution after debayer is around HD standard. The new Blackmagic studio camera which uses a smaller than 35mm sized sensor might be a good contender. What did you end up using?

Thanks again.


#10

It just required cutting into the wooden deck.

The prism is easy to remove and could readily be replaced again if required. My prism is actually up for sale if you would like a spare.

I 3D printed a disk tha I attached to one of the sprocket wheels on the unused audio only film-path, and used a hall effect sensor and magnets placed within the disk to trigger the light-flash, the delay is controllable in software to do fine adjustments.
I used a machine-vision camera that has a trigger port, so regardless of speed variations on the Steeny, the camera will capture when the frame is in the gate, again the trigger delay can be controlled in software. I didn’ remove the split roller.


#11

What lens did you use on the camera.
What size is the sensor?
Are you still using the original projection optic in the Steenbeck?

I assume you use the software which comes with the machine vision camera.

Thank you again for your information.


#12

Another curiosity question. Has anyone examined auto-darkening welding helmet panels as to

Whether they have spectral characteristics which can be colour-graded to neutral,

Whether they have reliable enough repeatable response for shuttering as an alternative to rapid switching of an LED source,

Whether they could be modified to respond to a triggering source other than their own inbuilt light detecting switcher.

My imagining is that they might be a self-contained affordable, almost ready-to-use light shutter.

The downside might be having to use an intense light source to illuminate through them, that this would trigger them dark if the sensing is in the LCD panel itself. The intensity of the light required to trigger them dark might be very intense and not feasable to use. The light sensing system may well have filters which might be removable so that lower light intensities might set them off. An optical interrupt might be as simple has a rotating disk with timing holes drilled into it, a lamp and a TOSLINK cable to optically transport the light to the sensor in the LCD panel.

The camera might have to be separately triggered from the same optical interrupter

Just a few thoughts on trying to keep it simple.


#13

Interesting thought, but controlling the LED flash is so easy, and relatively cheap, that I’m not sure why one would go the interrupter path.

If you did want to though, another approach would be to use a pair of active shutter 3D glasses from a 3D TV. They are already setup to trigger externally and operated at high speeds and have reasonably clear optical paths.


#14

Interestingly, it seems that Steenbeck is still in business and has developed its own film scanner, based on its flatbed editor film transport. It is a gold-plated price though compared with what I can afford or justify on the relative value of my film archive.


#15

Hi, is there a release date of a kinograph build for purchase? i’m asking because im working on a digitizing project with no much budget, and i have a lot of 16mm film (from 30’s to 50’s). I’ve asked Matthew the past year and he respond that will be in the firsts months of 2016.

Thank you! for your time and your hard work!


#16

Peter. A furthur query if you have time to advise. I have carefully dismantled the optical prism assembly from the machine. My problem is how to remove the prism. I assume you removed the prism with its drive shaft attached. This shaft runs up the centre of the hollow capstain shaft. There are two fasteners on the lower end of the shaft. One is a small bolt head. The other seems to be a flat disk with two wrench holes in it. I think the flat disk may be a locknut for the bolt. Any clues on how to remove that shaft from inside the capstain shaft will be appreciated.

For general information, the Steenbeck uses cogbelts and cog pulleys to keep the drive sprockets in sync. This machine has done a LOT of work. The belts are very stained and worn but are still working properly. I don’t know anything about them but cogbelts and cogged pulleys may be available as generic all-purpose parts. Cogged pulleys could be 3D printed. Cogged belts could be much harder to make.


#17

Peter. A furthur query if you have time to advise. I have carefully dismantled the optical prism assembly from the machine. My problem is how to remove the prism. I assume you removed the prism with its drive shaft attached. This shaft runs up the centre of the hollow capstain shaft. There are two fasteners on the lower end of the shaft. One is a small bolt head. The other seems to be a flat disk with two wrench holes in it. I think the flat disk may be a locknut for the bolt. Any clues on how to remove that shaft from inside the capstain shaft will be appreciated.


#18

Matthew. Likely you already know so please forgive if this repeats your researches.

The Steenbeck uses cogbelts and cog pulleys to keep the drive sprockets in sync instead of gear trains like many projectors. They seem to have less lost movement that gear trains but there is some unless a third tensioner pulley is added to a simple pair. My machine has done a LOT of work. The belts are very greasy, stained and worn but are still working properly. I don’t know anything about them but cogbelts and cogged pulleys may be available as generic all-purpose parts. Cogged pulleys could be 3D printed. Custom cogged belts could be much harder to make.


#19

@juanjullian there is no release date at this time. But we hope to have something ready by the end of this year!


#20

@agus35monk what size are you looking for? McMaster has a good selection of timing belts/pulleys and I’ve used them before. You would need to know a few dimensions, however, such as the diameter of the shaft, overall diameter of the cog, the number of sprockets/per etc.

Here’s an example of what I"m thinking of. Would these work? More options here.