Dom Jaeger

The minimum focus stop doesn't necessarily line up with a mark if that's you're concern, usually infinity is a hard stop though. Can you not use your camera to test whether the 3 ft mark lines up with an object 3 ft away?

Sounds like the belt slipped. On SR1s and 2s the motor stops in a fixed position so the belt timing determines the parking position. Should be an easy job for a tech to reset, though the belt may need replacing if teeth have been stripped or it's simply deteriorated.

Ah, if it's a 1.5x anamorphic then that changes the S16 capture area dramatically. The native 1.66:1 frame will expand out to 2.49:1, so barely any cropping needed to get to 2.39.

More or less correct, except if you are planning to crop for 2.39 then the capture area is 1.195:1 so you would be cropping the S16 frame considerably at the sides. Assuming the 70 degree angle of view relates to a S35 sensor in 2.39 anamorphic mode, then the width is more like 21.2mm for something like an Alexa Mini. You'd need to crop the S16 frame down to 8.85mm wide for 2.39 extraction. So the crop factor then becomes 8.85 / 21.2 or around 0.42 x. So 70 degrees would be cropped down to about 29 degrees.

It’s fine to use lenses that cover full frame on a S35 camera, the sensor just crops the image circle down. It’s only a potential problem going the other way, if you try to use S35 lenses on a full frame camera, then you can get vignetting.

Some lenses have two scales, sometimes one metric and one imperial, so there are sometimes two positions to mount the lens.

I wouldn’t recommend trying to do this yourself. Those lenses use a double helicoid focussing ring, with internal and external threads, that connect to the body and the mount. There are multiple thread starts, and each part needs to screw into the precise thread start for a precise number of turns in order to line up with the focus scale at infinity. There are other tricky bits that are easy to stuff up if you are not experienced in servicing cine lenses. I’ve had to rebuild too many Zeiss Super and Standard Speeds that were pulled apart by people who didn’t know what they were doing, and it can turn a 2 hr relube job into a five hr puzzle to solve. The greases are not molybdenum based, they generally use a synthetic hydrocarbon base and there are a variety of them available from Zeiss. I use one type for the helicoid, one for the guides and another for the iris ring. If you do try and do it yourself, make sure to measure all gaps at infinity and precisely mark where threads come apart. Take lots of photos.

This is the older style of Arri Standard mount that needs to rotate inside the camera or adapter mount, while the inside of the lens is located and kept from turning by a tab that fits in the slot at the back of the lens. The index mark was actually on the camera mount, and if memory serves it lines up with the centre of the tab slot. It should also line up with the aperture index mark, but if people have fiddled with the lens it might be shifted. Good quality adapters for this type of lens mount used to have an index mark on them, as pictured in this example:

Lenses marked "RX" or sometimes "DV" have a slightly modified optical design to compensate for the Bolex beamsplitting prism found in reflex Bolex models. The prism can introduce aberrations on normal lenses that are 50mm and under, though the aberrations are generally reduced the more you stop down. For an ACL or any C mount camera that's not a reflex Bolex you'd want to use normal lenses. If you did use an RX one it would probably be OK stopped down past around f/4. Be very careful with certain C mount lenses that have a mounting thread that extends more than about 4mm, like older AR (normal) Switar 25mm lenses, as they will screw in too far and can damage the baffle and potentially break the mirror on an ACL. I've seen a few broken ACL mirrors because of this. With adapters, you pay for things like material quality and machining accuracy, and whether the adapter spaces out to the correct flange depth. A Les Bosher adapter will be made from stainless steel, and should be very accurate in terms of flange depth and flatness, the PL lock ring will lock smoothly and at the right depth and the finish will be nicer etc. Cheaper adapters will be made from aluminium or brass alloys, which are more susceptible to wear, they may have burrs or machining defects, and they may not seat a lens accurately. If the flange depth is off even by a few hundredths of a mm it can cause a zoom to lose focus as you zoom out or a prime to not reach infinity. That said, the Raf Camera adapters are usually pretty decent. Be aware that PL to C mount adapters may not accept all PL lenses, or work on all C mount cameras. Check the drawing dimensions to work out compatibility. Again, expensive adapters tend to have been better designed to be more compatible. The Eclair TS adapters are exceptionally good quality, if you have one for Arri Standard you can use any Standard mount lens with it.

Yes H8 cameras are basically the same as H16s in terms of build quality and stability. Later reflex models in both gauges have better viewfinders, and the dedicated H8 RX lenses are extremely good, but there are plenty of nice D mount lenses for a non-reflex H8, like the little Switars. If you prefer smaller cameras, the pocket Bolex 8mm cameras (B8, D8 varieties) were great, not quite as solid as H8s, but really good for their size, and they take the same D mount lenses as a H8. Melbourne has a great film community, you're in the right town.

When you load the film with the loop formers closed, and it runs through the gate, it should be picked up by the claw just as a perf reaches it, and then the same with the lower sprocket. So you need to slowly hand crank the film through and first set the rotational position of the upper sprocket so that the claw picks up a perf just as it begins to move forward, and then set the rotational position of the lower sprocket so that a tooth cleanly picks up a perf when the film reaches it. If these are misaligned, either the film will jam or when you open the loop formers the loop will shift up and be off centre. It can be tricky to set correctly. There are two screws holding each sprocket in position, and when you secure them again you should also try to keep the sprocket height the same as you found it, with slight clearance above the guides. I have a tool to help set the height. Normally I would say this is a job for a tech, but see how you go. The alternative is to manually load and form the loop, or always check that the loop stays centred and never hits a loop former, and adjust it by hand if necessary.

That seems to be OK, but I would check it by slowly hand-cranking so you can really see if there's any movement. If the timing is only a little out the film will move just as the shutter is opening or closing, so I tend to mark the film with a squiggle that extends to the edges so you can see it even if the shutter is covering most of the gate. EBMs are pretty simple mechanically, there's no stop pawl or single frame or variable shutter to worry about, you just need to get the pulldown synched to the shutter. Some timelapse/animation motors need the 1:1 drive to be correctly synched to the shutter to work properly, in terms of where the pin and the red dot is. If you removed the front, you will need to remake the light seal. Did you de-solder the wiring and remove the mechanism? If so then the light seal needs to extend around the inside. If you undid the sprockets or shifted the claw gear you will need to re-time the auto-threading.

I’m not sure anyone ever made short extenders like that in Arri B mount or S mount, it was only ever 1.4x or 2x. And they generally don’t work with wide primes, only zooms or primes with minimal rear protrusion. The Optex conversion kits were replacement rear optics for the Zeiss 10-100 mainly, though I think they may have offered some for other zooms too. But they would have been all used up by now, I haven’t seen one for sale in many years. Maybe you’ll get lucky.

Yes, we often use custom optics to expand lenses, normally around 1.1x or 1.2x is enough without losing too much light or altering the focal length too much. The problem with off the shelf expanders is that they tend to be 1.4x or 1.6x which is often overkill and loses you at least a stop. Sometimes you can go to the trouble of expanding a lens only to find it's now the same focal length as a longer one in your set that already covered, but it's a stop slower and not looking so great wide open any more. They often also have shallow protrusion specs meaning a lot of wide angle lenses that stick out past the mount won't fit.

I think you have the wrong number there, 23mm diameter is too small. Normal 4 perf 35mm anamorphic needs an image circle of about 29mm diameter (22mm x 18.7mm), so all 35mm format anamorphic lenses will cover at least that. The anamorphic modes on Arri Mini LF which are designed for standard 35mm anamorphics tend to limit the frame diagonal to a maximum of 33.6mm, which in my experience most will cover, but you can get the odd one that doesn't. Testing will properly answer your question.

The only caveat is that Open Gate is larger than some 35mm format lenses are designed to cover. Even cropping the sides for a 1.85 extraction you would need an image circle of around 33.4mm diameter. The official V-Lite 1.3x sensor coverage is smaller than this, but I think most of the focal lengths should cover. You would want to test to make sure though. You might need to make a custom frame line slightly punched in to cover all the focal lengths.

You need to be more clear in your description. What slack? If you mean the loop, which you measure to the line when loading, then that’s meant to stay constant. That’s how a film camera works. Just don’t latch the film onto the gate until you’ve fed through enough and wound it onto the take-up core. With the loop still free from the gate you should be able to turn the gear and the film will move through from feed side to take-up, with the loop staying the same size. Only then, latch the film onto the gate, centre it and load the mag, Then manually inch or use the test button to slowly advance the film until the claw catches a perf. You can usually hear it catch. Read the manual thoroughly to understand your camera. If it’s still not working properly after that, you might need a tech to look at it.

Silicone is a pain to remove, and won’t just crack apart when the camera needs to be opened for service. Use a black caulking compound gap filler instead.

Yes, that glass is the reflex prism, a beam-splitter which diverts about a quarter of the light up into the viewfinder. It should be kept clean because the other three quarters goes through to the film to form the recorded image. It’s a bit hard to tell from that photo but it looks like the line on yours is a bit of separation, meaning the join between the glass pieces that make up the prism is starting to seperate. It might not have any effect on the image, but you’ll need to shoot some film to check. If you remove the filter holder and rotate the turret 180 degrees out of the way, you can flip the prism out in order to clean the back surface if necessary, and observe the ground glass surface on the top where the viewfinder image is formed. You can use a bulb blower to blow off any dust specks on there. This should be described in the manual.

No that's not a camera problem, that's how an SR mag works. The gear ratio for the belt that drives the take-up is such that the sprockets feed 18 frames or about 14cm of film through for each revolution of the take-up spindle. This means the minimum diameter for a take-up spool to snugly wind on the film is 14/π or about 4.5cm. A daylight spool hub is only around 3.2cm in diameter, so it won't wind on tightly until quite a bit of film has gone through, causing potential cinch marks. The solution is not to use a daylight spool for the take-up, but to use the removeable core that comes with SR mags, which happens to be about 5cm in diameter.

If your friend is not very experienced with working on lenses, and the lens is in any way valuable, then get it properly cleaned by a professional. Lens service is not something you can generally DIY unless you don't care about the lens and you want to learn. But I wouldn't be practicing on a Speed Panchro worth thousands. Start with junk lenses that cost nothing. Depending on the age of the lens, the coatings may be soft and easily damaged. The lock rings may be hard to undo, making it easy to slip and scratch the glass. To properly access every element you usually need to dismantle the optical block from the focus mechanics, which is not a job the average person should undertake. There may be cemented doublets with haze or fungus in the join, which will not be cleanable without splitting, which is definitely not a DIY job.

When does the film first jam, when it starts to enter the sprocket, or when it enters the gate, or when it gets to the claw? If the sprockets aren't properly aligned with the claw when the loopformers are closed it can cause problems with the auto-threading. Once threaded you should open the loop formers to see how it goes - does it move the film now? How does the loop looks - does it stay centred, or shift up and hit the loopformer edge? There may be other issues causing too much load for the motor - are you fully winding the spring so it's at its strongest or running the camera just before the spring runs down? Does the camera slow down when you run the spring all the way down? (Hold the take-up spindle to replicate the load of film being wound on). Has the camera been serviced by a decent technician recently? If not it could be that the mechanism needs a CLA, or the claw is not in tolerance, or the sprocket guides are too tight, or the film guide is deformed and making it hard for film to move through the gate, etc.

This guy has modified Kinamos with modern motors: https://www.instagram.com/kamera_doctor/?hl=en

I think probably one of the main differences comes from how well the viewfinder system allows the operator to accurately focus, which is a combination of magnification, clarity and accuracy in the ground glass setting. Then in terms of using lens marks to focus, you have things like accuracy of the flange depth setting, accuracy of the lens back focus and quality of the lens - including mechanical consistency as well as focus throw and accuracy of the marks. In those terms, professional cameras like an Arriflex or Aaton with a mirrror shutter and high end optical finders using professional lens mounts like PL will be superior to a Bolex with a C mount, or even something in between like an Eclair. Then you have the mechanical aspects of the film transport which determine image quality - things like steadiness, scratches or light leaks, flatness in the gate, etc. These settings might be stable or they might be more susceptible to wear or physical knocks. An Arriflex will usually be more durable than an Aaton or an Eclair, a Bolex will usually be more durable than a Beaulieu, etc. It can of course come down to how well a kit is maintained and serviced. As Simon mentioned, different shutter angles can subtly change the quality of motion capture too. Certain cameras can have common issues that can sometimes cause image quality to suffer - using a reflex Bolex without RX lenses, Scoopics creating pulsing exposures, butterfly shutter CP16s causing smeared highlights, cameras that need exactly the right size loop or they cause problems etc. But in general, a camera is only the box holding the film, the stock and the lenses and the cinematographer are what really make the image. A high quality camera just tends to allow those factors to reach their full potential.

Fabulous little cameras, I started a thread about them many years ago now after discovering one where I worked. I documented pulling it apart but alas those photos are gone now. It has the most ingenious spring motor drive gear that increase the gear ratio as the spring winds down, in order to try and maintain speed. Regarding the buttons and levers, it’s been a long time but I think I remember some. 1: I think this releases the lens 5: I think this disengaged the spring in order to use the hand crank 7 and 12: These were a basic framing guide, the back one was a lever that lifted up with a centre notch to align with the front part, which was a wire frame that swivelled up I forget the others, but I’m sure playing with one you could work them out.