Steve Switaj

I'm not familiar with the Arri S/B's. Where's the power connector? Is it a blind mate to that little metal pin at 7 o'clock on the motor face?

Buy some good screwdrivers before you start. You want the type gunsmiths use, with the ground, parallel sides. You can buy the kind with one handle and a set of 1/4" hex tip inserts to save some coin, but you want a set with a good variety of tip widths and thicknesses to choose from. If you use "normal" tapered screwdrivers from the home improvement store - even good ones - the blades will not fully fill the slots side-to-side and top-to-bottom and will concentrate force on 2 points at the top of the slot. Combined with the force need to dislodge some of the old fasteners, you *will* bung up these old, soft, slotted screws.

By the way, that black thing the film runs through just before the first roller might be a timing light. A lot of these cameras were used for industrial measurement, so it was important to know how fast they were actually running (which was at best an educated guess). Many of them were equipped with a little neon bulb that would flash at a certain rate, say, 100 times a second, and put a steady timing pip on the edge of the film so you could measure exact event timing.

>> Well, I am afraid to tell you that... I don´t know what do you mean with framing camera. My WF 14 is basically this one: Cool! I have one of these in a box somewhere! Never did get to use it, sadly. Anyhow, there were a few different options for the drum cameras, they were available as "framing" cameras or "streak" cameras. Framing cameras... well, they basically make individual frames, like normal film cameras. They are for high speed cine work. Streak cameras, on the other hand, move the film continuously behind a thin slit. This is useful for certain technical applications where you're photographing linear motion. It's basically a long still photograph *of* time going by, but it won't make sense as a movie. One common example of streak photography is the photo finish camera at a horse race track. Check out this cool write up for more insight into how it works... https://www.donttakepictures.com/dtp-blog/2019/5/8/winning-by-a-nose-the-history-of-the-photo-finish Anyhow, you can easily tell what kind of camera you have if you take off the lens port and look inside while you turn the drive sprocket. If you see a prism spinning in there behind the lens, you have a framing camera. The prism is geared to the drive sprocket and turns in sync with it. Light going through a square prism displaces the image as the prism turns through an angle (you can see this effect looking through a thick sheet of glass). This "sweeps" the transmitted image vertically along the face of the film on the sprocket behind the prism. The image moves along at the same speed as the film on the drive sprocket, that way the image stays sharp(ish) and the film never has to stop. As far a focusing, when you look through the finder, yes, you may see an image even if you don't have focusing film in the camera. The lens is always making an image at the focal plane, even if there's nothing there to show it (an aerial image hanging in space). But you still want to use a piece of focusing film because it's impossible to tell where exactly the plane of focus is with any precision. The focusing film behaves like the ground glass in a view camera, acting as a placeholder for the exact plane the film is soon going to occupy. You want to be careful that you place the frosted side (and therefore your focal plane reference) facing outside on the drum, where the emulsion side of the film is going to be. As for framing... mine has a circular hole that shows most(ish) of the middle of the frame, but you don't really know where the exact frame lines are. At least you can find the center and this was probably plenty good enough for the original technical applications.

Pro tip: Whenever you have to get a part custom made, always price out getting two, maybe three. The setup charges are often the largest cost of a custom piece. Once the setup is done having the 2nd or 3rd part run is usually much less expensive. Depending on the exact part, if you need it, there's a fair chance someone else needs one too, and by selling your spare you can effectively recoup some of the cost of the NRE. I'm always amazed when I do a custom electronics design and the client only asks for one. The NRE design cost itself is usually 80% of the bill, the actual fabrication ... is just a board. It's not unusual for me to quote something like "1 unit $2500. 2nd unit $1000, subsequent units $500 each"

Hi Guys; Fear not - You can easily do it yourself. It used to be that making shim sets was a pain because cutting the thin stock cleanly is pretty difficult without making a mess. But cheap laser cutters have changed all that. If you have enough skill to make a full sized pattern in a vector-graphics program, you can have your local laser engraving house cut out a dozen perfect shims from a sheet of plastic. I like the color-coded polyester stock that's used for "official" machinist shims. It's a known thickness and is as thermally and mechanically stable as you can reasonably expect from a thin film. It's available from .0005" to .030" (0.01 to .75mm) , so... something for everyone, basically. In the States, you can get it in 5" x 20" sheets, which is probably enough to make 7 or 8 if you space them well, available from McMaster-Carr for $4.26 ( https://www.mcmaster.com/shim-stock-rolls/color-coded-shim-stock-6/material~plastic/ ) or here's an assortment of 15 thickness for $44 https://www.mcmaster.com/9513K42/ In a pinch, you can try using some filter gel. Hate to admit it, but that has worked for me more than once. Some laser cutters can also cut thin sheets of stainless steel. Stainless foils can be found from about .001" and up ( https://www.mcmaster.com/metal-foil/stainless-steel/shape~foil/ ) If you prefer this option, try to find a commercial specialty graphics house, many of them will be familiar with using this material for masking friskets or paste stencils and have the tools at hand.

Hi Guys; I'm rebuilding an old camera and need to find a couple of rolls of scrap 35 mm film for tuning the servos. I've managed to snap all my test rolls into little ten-foot pieces, and now I need some more. Maybe one or two rolls of, say, 250' plus. It's strictly for physical testing, emulsion is not important to me, the film can be flashed or outdated, just so long as it's in decent mechanical shape.

Holy crap! I never throw anything out! This is the second weird connector request that I've found in my stash this week! Two of them, this time. No, I'm not a hoarder.... I'm a .... motion control guy. Yeah, that's it! There's definitely a difference. For sure. DM me.

I don't know if this applies to the Cannon parts, but on most versions of the Switchcraft XLR connectors, the inner contact block is held into the connector body with a screw, usually on the latching side. On those connectors, if you have a connector you need to change but a backshell style you want to keep, you can simply find a generic 4 pin XLR and swap the contact block between backshells. Don't know if this is the case with the Cannon brand parts, they are not common on this side of the pond, but it might be worth pulling it off and taking a peek underneath.

Aapo: I think I'd strongly suggest you use a smaller selector switch.. That long toggle seems awfully close to the exposed bottom edge right at the back, it feels like it's just crying out to get damaged from being pushed back on a shelf or dropped into a case at the end of the day. Maybe some kind of small rocker switch.

Also, I found one of those weird, WPI 9-pin connectors made out of unobtanium in a box of... well.. weird connectors. If anybody has a need for it, they can have it for what I paid, which was probably about $30, plus postage to wherever it's going. DM me.

Holy Crap, I apparently never throw anything out ! I had one of those "wait... I might have something.. " moments, and I dug around in some old project files, and in a folder marked "Aaton" I found a paper printout of part of an email conversation I had with Clive Tobin 21 freaking years ago about Aaton sync. To be an FX camera guy is to be a technical packrat. I don't know the exact question I was asking, but IIRC, I was in Australia working on the Matrix sequels and I wanted to use a couple of LTR's as 2nd-angle witness cameras for some effects we were shooting on VistaVision plates. I think.

3/3 The final user controls closely follow the pattern of those on the Arriflex 435 - I figured that any professional operator would be familiar with that. One thing that I felt was a big improvement was that I replaced the original 25-hole speed sensor disk with a modern 800 count quadrature encoder. Having 32 times more resolution dramatically improves speed control, but more importantly it allowed me to derive the signals I needed to update the accessory port from the original Fries type to an industry-standard 11-pin Arri port. This camera will be used in complicated VFX settings, so it has to interface with all the equipment that modern cameras are expected to work with.

2/3 A few years ago it coughed and sputtered out the magic smoke and decided it would run no more. It sat on a shelf for several years till the owner asked me if I could return it to operation. After about 30 minutes of tracing my way through the original circuits I realized that it wasn't going to make any sense trying to repair the mid-80's electronics. Fries had closed years ago and there was no information at all available, and even if there were, the design was built around old analog circuits and it didn't seem like a good basis for a camera controller in 2022. I figured simply rebuilding it from the bottom up was the best way forward. I designed two new boards for the camera. The first was the main control board, this included the user interface, external interface, and an LCD display. Oddly, the new boards kind of look older than the originals. The original boards used surface-mount chips but the new boards use through-hole chips so that anything programmed or exposed to an external interface could be socketed for easy replacement. Truth be told, I would have liked to use a better display. This old-school yellow/green LCD kinda screams “1990's vending machine” to me, but with supply chains being what they are, and this being a one-off, it didn't make sense spending the the time to do anything more complicated, especially since our user base only cares about the data, not the look. The electronics are otherwise straightforward. At the center is a PIC24EP family chip at 70MHz that coordinates everything. This chip has a built-in quadrature encoder interface and three PWM generators, so it makes motor control easy - once you decode the truly byzantine Microchip datasheet for these modules. There are 3 motor drivers, one each for the camera motor, takeup hub and supply hub (for backwinding). The motor drives are all unidirectional (the camera motor has a hardware reverse switch) so the 3 drivers are all 1-quadrant, simply a big MOSFET driving the low leg. The switching frequency is 20KHz to make it inaudible, which I soon realized was pointless since the camera sounds like a washing machine when it runs - it was obviously not designed for sync-sound work. The speed is variable from 1.000 to 36.000 FPS in .001fps intervals. The control system is a standard PID loop updated at 1KHz. Between the fact that a camera motor is commanded to run a constant speed, and the large rotating mass involved, the derivative term is basically useless, so after a little testing I just dropped it.

Hi Aapo; I've been following your cool CP-16 crystal sync project with great interest, and I wanted to share my own camera controller project. I'm kind of working at the other end of the scale, though. I got a project rebuilding the electronics for one of the old Fries VistaVision conversions. This thing is monstrous, It weighs in at 40 pounds without lens, mag, film or even finder.

Hi guys; I was cleaning up and came across a small box of follow focus bits. I have no use for them, I think they came along with an auction lot a few years ago. If they are useful to anyone out there, you can have them for the price of the postage. 1 cable - Lemo 3 pin FG1 to Lemo 2 pin B1 (Panavision run to Panavision accessory?) 1 cable - Lemo 2 pin B1 to Lemo 2 pin B1 (Some kind of Panavision accessory power?) 1 Bracket - probably a Preston Hand Unit I/II to microforce I/II 1 set of 5 follow focus marking rings, flat, 2.58" ID, 4" OD 1 set of 5 follow Focus marking rings, flat w/ metal on the reverse (for magnetic mount?), 1.2" ID, 3.6" OD, marked "Cine-Pro" DM me if you're interested

Be nice to see the other side. If that's a detachable mag, the body in front of it looks pretty shallow, Kind of looks like it could be set up like the old PhotoSonics, with sort of an in-mag movement that clips onto the port side

>> should any generic BNC antenna work as a replacement for the hand unit? Well, you're probably going to have to have _some_ idea of what frequency you're dealing with. Getting this exactly right is less important on the receiver than the transmitter, but you want to be in the right ballpark. I don't have anything here in front of me but there might be something in the documentation or look for a sticker on the transmitter unit, often there's a FCC mandated label. Assuming you're in the US, go to the DigiKey website, RF/IF antennas page https://www.digikey.com/en/products/filter/rf-antennas/875? Narrow the search by putting in your frequency band in the "frequency center band" column (6th over) and check 'BNC' and 'BNC male' in the "termination" column (15th over) There are about 60 hits for little BNC stub antennas in a variety of frequencies, so if it's just the missing antenna, it's likely you'll be able to find a reasonable replacement there. >> On the MDR side does anyone happen to know what the deal is with snipping the pins? It was probably just a matter of limited space, and the antenna was only using one pin... so....

Aside from mechanical issues, another problem would be controlling the iris. Your mount would have to make provisions for the electrical connections, and some sort of controller would have to be built that could send (at least) iris commands to the lens since most of these lenses no longer have a hardware iris ring. It's not rocket surgery, but it takes up space in an inconvenient place

The connector looks like something out of one of the Molex pin & socket families, but there are a bewildering array of options to those. Can you measure the pin pitch? Common pitches are 6.3, 6.7, 7 or 9.9mm

The circuit board is a voltage regulator. The chip is an LM2596, a common step down switching regulator, the black potted cylinder is an inductor. The blue trimmer pot in all likelihood sets the output voltage, that type of pot usually has multiple turns, so they are used for fine adjustment.

Just working from muscle memory here, and it's been some time since I did wheels, but I seem to remember exactly the opposite: Left-hand wheel == Pan, CW looking at wheel == pan left Right-hand wheel == Tilt, CW looking at wheel == tilt up

Ohh...Kay... Whelp, this is a weird one. It looks like you have the 120v synchronous AC motor. Again, I'm working from memory, but I seem to recall that this camera came with either the 12v governor motor or, as an option, a AC line voltage motor, and it looks like you have one of the later. That's not totally weird, since an AC motor was a fairly common option for both 16 and 35 mm cameras that were used in a studio setting in the 60's and 70's, since they gave better speed regulation and removed the need for batteries in an era when batteries kinda sucked. That being said, someone has clearly modified things after the fact, since that is definitely not OEM Arri wiring. I have no idea how the power is hooked up. My BL and every other one I've seen had a 9 pin connector mounted just aft of the motor housing. It's hard to tell from the photos whether your camera had this removed and the hole plugged, or whether there was never one there in the first place (although that right-angle piece on the rear plate looks suspiciously like the part that was used to mount the connector). Somebody has apparently bypassed all this, maybe to install a preferred connector I am pretty much at a loss here. I am unfamiliar with the 120V motor, but if it works, then maybe you can find someone to clean up the wiring and you can operate it off line voltage. You probably don't want to go experimenting with this motor until you get a more solid ID on it. You especially don't want to try putting DC voltage on it unless you know what specific kind of motor it is. Many types of AC motors don't have enough coil resistance to properly limit the current that flows through them. These motors instead rely on the inductance of the windings interacting with the line frequency to limit current to a safe level, and this scheme doesn't work with DC. Conversely, some motors are fine with either flavor, and are just as happy to run on AC as 120v DC. I have no idea which kind Arri used, but to me "synchronous" implies frequency dependent because universal motors tend to have a lot of phase slip. Also, just for reference, the preferred way to remove and reattach the motor in this camera is to remove the spur gear first. I don't know if it's just an urban myth, but Arri advised that the gear was less likely to be damaged that way. I honestly don't remember how I did it with my camera. To remove the gear you take out the screw in the shaft. Obviously, this means that you have to pull off the little plexiglass gear window. Be very Very, VERY careful when you put the window screws back in, it's really easy to crack the little mounting ears with excessive screw pressure. I cracked one of mine that way.

Hi Keegan; I had a day to think about it some more, and to look up some things, and I realize that I got some things kinda mixed up in my first post, (I've seen the insides of a lot of cameras and they all start to blend together). I think I have a better answer for you, and it actually looks better for you than I thought it did yesterday. The cavity in the back of the camera used to house a circuit board that was used to mark the film and generate a sound tone used for post production sync. The open hole is disconcerting, but the camera can run without it. The circuit that does the speed regulation is inside the camera, built up around the motor assembly, and if my memory is working right today, I don't think it's all that complicated. The base model motor (probably what you have) had a mostly mechanical governor similar to the one found in the motor for the ST, there were just a few electronic components controlling a big power transistor, which in turn supplies a regulated current the motor. The signals in this drive circuit were accessible to the outside world through a 9 pin circular connector, located on the right side of the camera, in the bottom rear corner (not the one up above the motor, that one is for sound). This 9 pin plug provided power and allowed for connection to the pilot tone generator and, importantly, to the motor drive transistor. Power used to connect here. Commercial crystal sync units also connected here, where they would use the pilot tone feedback and take over driving the big power transistor, to control camera speed precisely. Bafflingly, you do not have this connector anymore. I can't tell from the photos if it has been removed or maybe you had a weird custom camera where something else was installed. Either way, somebody has clearly modified things since this camera rolled off the line in the late 60's because that is not the type of wire Arri used back then. Heck maybe you really lucked out and got a camera that had an upgrade motor installed (that would be pretty sweet, actually), and for some reason whoever did the job decided to take the power out the back for some reason . I suspect that you'll have to investigate further by removing the motor cover and looking inside. It comes off easily with 4 screws. Pop it off and send us a photo or two of what's in there.

Wow, this takes me back 30 years. The first movie camera I owned was a BL16. I slid sideways into film from a previous career as an electrical engineer, so the first thing I did with my new-to-me camera was to disassemble it and reverse-engineer it in order to build a crystal sync box. Ah.. the good old days. Try doing *that* with an Alexa. Anyhow.. The cavity in the back of your camera is supposed to hold a circuit board for speed regulation. Most of these cameras shipped with an analog speed controller that wasn't really crystal sync, but kept them reasonably near a constant speed. The motor shaft included a tiny alternator that would generate a “pilot tone” near 4800 Hz, and that tone would be sent to the audio guy who recorded it on a separate audio track. That tone was mechanically tied to the frame rate so as the camera wandered, so did the tone, and the audio rate could be resolved back to the film rate in post. There were true speed accurate controllers available ( the crystal sync everybody talks about, named when crystal timekeeping was still a new thing ) which compared this pilot tone to a crystal oscillator to keep a precise 24 FPS. They were external devices which plugged into a 10 pin Amphenol connector on the regulator circuit, which you are missing, or later, when electronics got small, replaced the regulator entirely ( Clive Tobin used to make one like this ). Either way, these circuits interfaced with the innards of the camera through that blue multipin connector, which, I'm assuming is... well... now disconnected. Don't know what the red and black wires are about. Maybe someone took the express route to power the motor. Also, where does the blue wire go? And what's with that cable clamp? That is not original equipment. First, I think you'll have to determine how much has been shuffled around inside the camera. The motor is under the cylindrical cover on the right of the camera. Take out the 4 screws and pull it off so we can get a look inside. Specifically, we're looking to see how the power to the motor has been modified. It used to be driven PWM-style by a large power transistor mounted to the frame (looks like a flat silver disk the size of a quarter). Also, we want to know if the pilot tone generator is still intact (that's still required because we need a feedback signal) Post pictures. Also, while we're at it, open the camera door. Right in the middle of the camera you should see a clear plastic plate with a couple of gears visible under it. The gears should be stamped either 24 or 25, indicating where the regulated speed was initially set up for either film or European TV speed.