Dom Jaeger

Well there is only one iteration of the Arricam LT, Arri never released an LT 2 or an LT Advanced, so if there was a first version it can’t be very different. I imagine maybe just a few accessories hadn’t been released when Fauer wrote the first edition of his Arricam book.

I don’t think there was a different generation of Arricam, just a second edition of Fauer’s book.

"Is there something I should be doing to be more careful about back focus, or will I generally easily see a problem.?" The productions I deal with where I work need their lenses and cameras perfectly set up. They use focus marks, and the zooms all need to be parfocal. The end results often end up on large cinema screens or high resolution TVs. So I have to work to very high standards of accuracy. I have no idea what your client expectations are, but if you or your clients haven't noticed anything or complained, then I'm not about to tell you that you need to double check everything. Horses for courses. As I said, back-focus errors tend to show up in wider lens focal length marks being a bit off, or in zooms getting soft at the wide end (after focussing at the long end). A wide angle zoom ticks both those boxes. If you have a monitor that is at least as good as whatever the final viewing specs are for what you produce, then you should be able to see if you have any issues.

Sure it's possible. I'm a tech, so I'm always checking back-focus and flange depth just as a routine, but a lot of owner ops just wing it. I guess if your other lenses seem ok you can probably trust the camera. Back focus/flange depth errors tend to show up more on wider lenses but it can be hard to judge wide angle focus without a good monitor.

Yeah if you've ruled out a power supply issue by using a healthy 24V block battery then it's time to send it back to the doctor.

The difference between cine and still lenses is not in the optics, it's in the mechanics and in matching the colour and look across a series. There's nothing inferior about the actual optics of still lenses. The Tokina Cine version of the 11-20 is pretty good value for the price, and has decent cine mechanics. But you do get what you pay for, and no sub $5K cine zoom is going to be without compromises. I would recommend having any cheap wide angle zoom checked for accurate back-focus before using it on a serious project, since it needs to be very accurately set to be properly parfocal and quality control at this price range can be variable.

According to Bolex Collector the Bolex anamorphot system was first introduced in 1958. http://www.bolexcollector.com/accessories/filter50.html

No cine lens will ever be marked as anything other than the focal length it is. There will be a multitude of different angles of view (“equivalent to x on y format”) depending on the camera and sensor mode you might shoot with. If someone feels the need to refer that back to a format they’re familiar with they just have to do the crop factor calculation. As David mentioned earlier, S35 and Open Gate on a nominally S35 camera like Alexa Mini are different sizes and will give different views with the same focal length. An Alexa 35 or Sony Venice or Alexa LF or RED whatever will all be different again, depending on the sensor mode you choose. There are other factors to consider as well, such as whether a particular lens covers a format larger than the one is was designed for. Not every lens in a S35 kit might adequately cover Open Gate mode on a S35 camera for instance. And some S35 lenses will actually cover full frame. The only constant is that a particular lens will always be the focal length that it is. (You can alter a lens focal length and image circle by adding focal length extenders or speed boosters, but in this case you’re adding optics to the lens, so it’s a different scenario.)

The camera serial number dates it to 1952, but who knows when it was modified. It has 16mm sprockets, but they will run double 8mm film, since that is essentially 16mm film with extra perfs. The curious question is whether the mechanism has been modified to advance only an 8mm frame height per exposure. That would have also required a specially modified projector. The other alternative is that it’s simply a 16mm machine with a heavily cropped aperture, allowing the resulting film to be run in a 16mm projector with a similarly cropped mask. The H8 reflex uses C mount, but that is a totally different camera. You can identify the H8 RX lenses by their unique focal lengths - 5.5mm, 12.5mm and 36mm - which you won’t find in Kern C mounts made for 16mm.

Well you sort of answered your own question - “assuming the adapter is set at the correct flange distance”. If that’s correct, and your 16mm camera is also correctly set, then it should work fine. If you have a non-reflex Bolex you can use the top viewfinder to check focus and see if it matches your focus marks. Or find a compatible prismatic focusser to check focus at the gate. Or just shoot a test and see how it looks. Or have a technician double check everything with a collimator.

Might have to send it to Simon Wyss in Switzerland.

It worth remembering that Arri Standard mount was superseded by the Bayonet mount in 1965, so this adapter would have probably been made for zooms made before then. Is your 25-250 Angenieux a MkI because any other version would be later than that. Usually an anamorphic rear adapter would have a key way or slot in the mount base for orientation..

It’s similar to modern digital cameras where you also can’t use a mechanical depth gauge - you have to optically measure it using a test lens that is perfectly calibrated. With a reflex Bolex you can actually measure the distance from mount to gate with the front removed using a micrometer, measuring from the outside rather than using a depth gauge, but because there are variations in the thickness of the prism (a tolerance value the Bolex repair manuals describe), you actually need to use a calibrated test lens and a collimator to check and set the appropriate physical flange depth.

Fantastic work Erren, well done!

If you think you can apply lubricant to a lens with a dropper you are not experienced enough, I’m sorry. Lenses are never lubricated with oil or otherwise liquid lubricants, only ever grease. And the right sort of grease. Oil, or grease that separates and releases oil, will eventually leach onto optics and iris blades. And you need to thoroughly remove the hardened grease first, otherwise the focus will never feel smooth. You shouldn’t have to remove any optics to clean and relubricate the focus helical in this lens. The helical is in the rear part that is removed at the very beginning of the video. But you also need to remove the focus ring and clean and lubricate that part. There is a different way to remove that ring for each Kern prime focal length. It’s easy to lose the focus calibration so make sure to mark and measure everything before taking things apart. You also need to be aware of the rotational position of the C mount for the right index mark position when fitted to the camera.

We use a product called Emralon to rebuild worn focus threads, it’s sprayed on in layers and baked to harden. Then the threads are lapped back. As I mentioned before, it reduces focus backlash and image shift.

You can’t see the gate in that photo. That’s the light meter cell. But from the condenser optic above the ground glass I doubt it’s S16.

Yes that price seems reasonable. The spraying and baking of the helical is probably the biggest part, can be tricky and time-consuming to get right. Many 16mm format Super Speeds end up with a bit of wear to the threads that can cause image shift and focus backlash, and this is the only cure, other than rehousing. Gregg, feel free to PM me about Zeiss Super Speed service, I fix these all the time and I’m a lot closer than Duclos. Get a quote from them first if you like.

Hi Uli, Sounds like the aperture ring threads need lubricating with the right grease. But to access that part of the lens you have to come all the way from the back, which requires full disassembly of the focus helical. While not particularly difficult, it does require knowledge of how to mark and measure the helical spacing and thread starts for re-assembly, and then a collimator or projector for checking. Chances are the focus helical could do with a relube too while it's open. I'd strongly recommend giving it to a professional.

The 35mm camera used was an Arri 2C which uses a side rail for lateral registration.

How much thinner is B&W movie film, anyone know? The specs for stills Tri-X give a thickness of 127 microns, while colour neg tends to be around 140 microns, so there’s not much difference there. I’ve personally never heard of adjusting the pressure plate tension or channel spacing for B&W. The only thing B&W film usually requires is a blackened pressure plate due to the lack of rem-jet.

Well, like an old car that starts to make strange sounds, your camera needs a service. Something in the meter cell retraction mechanism is not working properly. Unfortunately ELs are the hardest Bolex model to service and many techs don’t work on them, so I don’t know who you can send it to sorry.

We've had to replace a number of rental camera sensors due to laser damage. If you point a laser at a rental camera, be prepared for a $10K bill.

The one for reflex Bolexes is 4x17C. It has a corrective element to compensate for the Bolex prism in the light path. It will introduce slight aberrations if used on a normal C mount camera at wide apertures. The exit pupil is fairly deep, so the Bolex prism has only minimal effect.

It's your lens, so do what you like, but essentially you should never use oil on a lens. Helicoid grease is specifically designed not to seperate and allow oil to migrate. If you squirt oil in, it will travel, especially on warm days. If oil gets on the iris blades it will gum them up (devastating with stills lenses that use a weak spring to close the iris), and it will cause iris reflections. If oil gets on an optic it will cause image degradation and eventually damage the edge blacking. So from a professional lens technician, the advice would be don't do it. But it sounds like you have nothing to lose if you don't want to pay for a CLA. Where to access the helical is another question, it's unlikely you'll get near it without at least some partial disassembly.