I was thinking it wouldn't be too hard these days to DIY something with a sprocket and some kind of encoder or RPM sensor to time the flashing of an LED panel in sync with a variable speed rewind (manual or otherwise). Just a tiny bit more engineering in the optical domain and you basically have built a poor man's Moviescop. The crux would be the sources for the film rollers and sprocket... but probably some old relic that could donate such things. A half broken film counter, etc. Could probably integrate the sensors it into a film counter or neumade synchronizer if you really wanted.
-
-
FWIW, I used to service RTI film inspection machines. Some of those had small viewers attached, where you could do quick pix and sound evaluations. Been many moons since I saw one, though.Comment
-
There was a viewer I believe called a Acmate or something similarComment
-
The Moviscope, the Acmade Pic Sync, and the film editing flatbeds (35mm and 16mm Steinbeck / Moviola / KEM) all had rotating multi-faceted prisms. The rotating prism is inside of a large diameter sprocket that is driven by the film (it isn't connected to any motor). When the frame is dead on, the prism face on the film side, and the face on the opposite side, are parallel with the film. There's a lamp on the other side of the film from the prism, usually shining through it via a 45 degree dichroic mirror (that can be pushed out of the way to mark the film). As the film moves away from dead-on frame, the facets on the opposite side of the prism become angled, so they bend the light and compensate for the shift in position of the film to keep the image stationary. Once you have the frame line centered in the gate, it is across from the point of the prism, and then as you continue to rotate, the new frame and another prism facet rotate into position. It makes a soft dissolve effect on the top and bottom of the frame. This way the film movement is constant and you don't need any intermittent or any spring tension against the film. I used to service these machines in the SF Bay Area. The picture isn't terribly sharp, but it is sufficient for editing. I worked at a sound mixing studio and we had a prism projector that ran synchronous with the film dubbers. They are very gentle on the film, and you can run single-sided splices through with no problem forwards or backwards at normal or high speed. All to say that using the picture section of a 35mm flatbed or prism projector, you could presumably construct a bench viewer. I don't think that the flashing light would work without an intermittent.Comment
-
Neat mechanism! The strobe approach would be no where near as viewable as the rotating prism, but having played with one and a rewind, it is a big step towards view-ability over nothing, giving a real sense of what is on the film, I think at speeds above 12fps or so our “persistence of vision” starts to kick in and do some of the work for us.
I was playing with a bulb type strobe though, but I’ve also seen similar results with a simple strobe app for my phone, though mileage may vary depending on the LED responsiveness.
Perhaps somewhere between nothing and a prism based viewer.Comment
-
I think I've found the solution to what you are looking for! They are "machine vision" strobes used for reading bar-codes/QR codes in a package sorting facility. It could be mounted underneath a 35mm synchronizer and shine up through the synchronizer sprocket wheel flanges with a diffuser. They have trigger inputs, where the illumination time is equal to the pulse length. So, let's say you determined that a pulse of 1/100 of the frame rate gave a reasonably viewable image. Then you could use the synchronizer wheel flange as an encoder and put a mark 1/100 the width of a frame at every frame line.
Comment
-
Interesting industrial niche. That link wasn't to a specific product... did you see one you thought appropriate? I'm sure there is a price penalty for the industrial nature of these. Fun to think about.
In a quick browse I had found this one that might suit your thoughts of mounting it between synchronizer flanges. 25mm x 25mm the only one that would fit. But lacks the trigger features you mentioned.
https://smartvisionlights.com/produc...ni-backlights/
Edit: Ohh wait I get your idea. Light separate from sychronizer... just using the sync to get the trigger... and otherwise the light can act light a normal light table, just a strobing one. ;-) No size restriction.Last edited by Ryan Gallagher; 10-25-2025, 12:09 PM.Comment
-
If you look on the datasheet for that light, page 3 gives the specs for the NPN or PNP triggers, and page 6 has a diagram showing the light output corresponding with the pulse duration. I was thinking of putting it under the synchronizer, as you could mask the light to the size of one frame, and even mount a magnifying lens over it if you wanted. The problem would be getting rid of the shadow from the synchronizer axle, or to find a model compact enough to fit over the axle between the wheel flanges. But your suggestion to make it a light table just to the side of the synchronizer sounds much more practical, maybe with the synchronizer on one side, and a wide-flange roller on the other to keep the film level across the light,.Comment
-
Here are pictures of an Acmade model (not mine, wallpaper also not). The Moviscop is a great viewer for 16mm (or regular 8 ) but Zeiss didn't manufacture 35mm models. A viewer (almost) as compact for 35mm would be a very handy thing indeed.
AcmadeErithKent-1.jpg
AcmadeErithKent-2.jpgComment
-
Speaking of weird viewers... a bit ago this oddball cropped up on ebay:
"All Angle 70MM Film Viewer Loardstown Tool And Die Model 100"
To be honest this seems like a repurposed 70mm photography roll negative viewer. Just a bench mounted loupe the film passes through. I would be pretty afraid of it's film "handling" characteristics to sling a whole reel through it on rewinds! Some of the rollers didn't seem shy about contacting the image area.
70mm Viewer.png
Listing is ended but here are the other photos at the original listing link:
https://www.ebay.com/itm/187706094453
Comment
-
A 16mm version of that Acmade design with TWO viewers is actually on ebay right now. Quite a contraption.
https://www.ebay.com/itm/187458297458
Acmade_16mm.pngAcmade_16mm2.png
As well as what appears to be a later model Acmade 35mm version similar to the one you posted. Although upon comparing, this one appears to be missing the light source unit.
https://www.ebay.com/itm/187643503923
Acmade_35mm.pngAcmade_35mm2.pngComment
-
Dunno if this has been shared yet, but there are some open source solutions that take up a similar playback philosophy. The Wandering Projector project has a functional implementation of a software emulated shutter that listens to a hall-effect sensor on a 1:1 shaft. I’ve done this conversion and the shutter blade emulation is very reliable and clean, but I had to change some things around for additional functionality. For lower powered applications like viewing on/thru a gang sync with an LED modulated by this software, one could strip this code to just strobe an LED in time with the position of a synchronizer. The action which checks the virtual shutter position is solid and runs on interrupts. This code might be a good start and the LED doesn’t necessarily need to be the same one used in this project.Comment
-
The mech is a ripoff of the early Charlie Ajar (Universal Projector Co.) location machines, the same design he later sold to Christie for their belt driven P-35 Series. The main legend of McCormick and Atlas Projectors is they were terrible designs, always cheapened versions of better machines. Many used proprietary parts that were unobtainium except from Atlas, at prices they were VERY proud of. (Worse, since each machine was hand built the tolerances were so bad that parts never seemed to line up without a lot of fiddling.)
Those in the listing are worth maybe $200 EACH (if you plan on using them for projector parts spares), and in reality are only worth scrap metal prices since they are missing ALL of the key parts.
With the ridiculous prices in most of the listings in this thread, maybe it's time to revive our "More junk for sale on eBay" thread from the old forum....
Comment
-
>>Warning! - Grab a cuppa coffee and a comfortable chair. . this is going to be a long post! <<
Atlas Projector Co was down in Los Angeles I think, and built custom 35mm projectors that
were mainly seen in screening/preview/editing rooms and film labs, and they also built custom
models for specific purposes such as museums and amusement attractions. All the ones
I've seen used 'guts' (ie: sprockets, intermittents, various sound components) that were all
manufactured by Simplex. There was one at a film lab I worked at, and I used to occasionally
run a pair of them in a preview theater/sound mixing room for Francis Ford Coppola at Zoetrope
here in San Francisco, and oh. . .by the way, I also own one! As preview machines they had the
ability to run in forward and reverse, some at variable speed, and to play mag-tracks in sync.
They had change-over capability, and as an option, they could be equipped with encoders or
selsyn motors to sync playback to run multiple additional optical or magnetic sound tracks on
rack mounted optical or mag dubbers, or could even be synced to run tracks from one or more
flatbed Movieolas. They came in many different models and configurations and I think most were
custom built for each customer.
My machine is currently in storage over at a theater here in San Francisco, but it was my main
"home machine" for many years. It was also rented out several times to movie productions
filming here in San Francisco to screen dailies and rough cuts, back when movies were still
being shot mostly on film. (as God, and Edison intended) Zoetrope knew I had one and once or
twice I let them borrow my intermittent movement when one of theirs began acting up until they
could get a new one, and I also had a spare Technicsope™ movement that they used for screening
dailies on two films they were mixing in that format. Zoetrope's machines could be completely remote
controlled (including focus and framing) from a couple of custom built hard wired remote boxes, one
located near a seat in their preview auditorium, and the other one was located near an audio mixing
console.
My machine is currently being stored at a theater here in San Francisco, but I
found an almost identical model pictured in a 2 decade old post here on Film-Tech.
The main difference between this one and mine, is that this appears to have a
Simplex "standard" projector head. Mine, has a late 60's or early 70's Simplex
XL projector head, and all the other Atlas projs I've seen had XL heads too.
AtlasProj.jpg
[photo credit: Rick Force - FT Post 2005)
This is more or less the 'stock' model Atlas Preview Projector, which is basically built
around a Simplex projector head. This one appears to be a Simplex Standard, but all
the others I've seen, and the one I own, have an XL head on them. The XL's have
an oil pump modification that allows it to work in both forward and reverse. The upper
feed spindle is motorized to work as a take-up when running in reverse, and there is
a switch to adjust the motor torque for small (1k) or larger reels.
There is a mono amp and exciter power supply built into the base, and a mono speaker
on the front. There was also several belts and clutch mechanisms to drive all the reels
in the right direction when needed. I made a number of modifications to my projector:
> I added a 4track Ampex mag penthouse on top, with pre-amps and audio connections
in the base. ( I had access to a large number of old mag-track musicals at the time)
> I never updated the optical to Dolby Stereo, since almost all the prints I owned were
mono anyway, but I did add an audio output so that I could bypass the internal speaker
and feed it into a better one.
> I modified two of the take-up reel spindle shafts to be removable (like on a Kelmar
rewind bench) and by doing that, I could fit a 5K (yes "5k") take up reel on the bottom.
The top feed arm was already long enough to handle a large reel.
> I added an hour-meter, to track usage. (mainly for when I rented it out)
> The 'stock' lamphouse as you see here used a 1200W "BRN" bulb. I used that
a lot at home, but I also had a small Xenon lamphouse that could be easily swapped.
This machine came from an advertising agency here in SF that only used it to screen
answer prints for TV commercials they were working on. I was working on editing one of
their commercials,( on 1" videotape!)) and somehow this machine came up in the conversation,
and the advertising guy told me that now that they were doing almost everything on videotape,
they were in the process of building a new 'tape suite/media room' and this projector was just
in the way. After the editing session, I went over to the agency to inspect the projector and
made an offer to buy it. The agency guy said he'd have to talk to his boss. The boss informed
me that he already had another offer, and thought the best thing to do was to hold sort of a
'silent' auction. This was in the early 80's, so everything was done by phone. He set a
'closing date' about a week away, and every other day I'd call and all he'd tell me is that
the other buyer 'had put in a larger bid" and gave me the opportunity to increase mine. On
the final day of the 'auction', when i called and asked if I had won the auction, the guy was a
bit hesitant on answering, and said that the other potential buyer had submitted a 'final bid'
(without mentioning the amount) and suggested I increase my final bid by 'a few dollars' .
- - and with that, the projector was mine. I wound up paying just over $3k for it. (a bit over
$9k in 2025 dollars) . A few weeks later, at an editing session, the agency guy confessed to
me that, technically, the other bidder had won the auction. But that person was a well known
projector collector, who already had well over a dozen or more other 35mm projectors, and the
agency guy saw how much I wanted this one, and said 'he liked me better' - so he 'fixed' the
auction in my favor. An an old Atlas Projector catalog I found at a film lab I later worked at priced
that machine from $8,000 - $12,000 depending on configuration .
Each projector was custom built - - so I think $3k was a good deal
But wait- - there's more!
All that stuff from Tom McCormick & NT Audio in the listing you shared in your post was first
posted on e-bay a little over a year ago. Included in the original listing were a number of SMPTE
and Dolby optical and magnetic test films, and RP-40, not in 'loops' but in lengths ranging from
several hundred to 1,000ft, and much of it was still in unopened (abeit almost a decade old) film
cans as originally purchased and received from SMPTE. I wound up buying almost all of it.
Ok. . you can go now- - - - - -
Last edited by Jim Cassedy; 12-02-2025, 12:45 PM.Comment
Comment