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Dom Jaeger

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Dom Jaeger last won the day on August 9

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About Dom Jaeger

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  • Occupation
    Other
  • Location
    Melbourne, Australia
  • Specialties
    Cinema camera and lens technician

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    http://cinetinker.blogspot.com.au
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  1. The lowest capacity Bescor 12V battery belt I can see is 7 Ah, which should be more than enough. You should be able to get through at least 5 thousand feet with that. Get one with a 4 pin XLR connector and charger. Higher capacity belts will be heavier, more expensive and not necessary. I've never worked on Bescor belts, but I imagine recelling one shouldn't be too hard. I used to recell Cine 60 battery belts all the time. It's easy to find lead acid cells.
  2. I’m not in the US, but some places I know that specialise in 16mm equipment repair are: Visual Products Whitehouse AV Super16 inc Other shops that are cine lens repair specialists: Duclos Focus Optics Cinematechnic Others may have more personal recommendations.
  3. As already mentioned, lens breathing and distortion (in the sense of barrel or pincushion) are not things a filter or coatings can change, it’s part of the lens design. But plenty of other aspects of lenses - contrast behaviour, optical aberrations and out of focus character especially - are tweakable. For professional productions that want the look of anamorphic, they can usually afford to rent anamorphic, but sometimes DPs want a hybrid look. You’d be surprised how much lens “defacing” goes on these days on many professional productions. I think Panavision began the trend of detuning lenses about 10 years ago, and now they lead the industry in this sort of bespoke lens fiddling. Very frequently there are multiple sets of detuned lenses on high end features and series. There are a huge number of things you can do to a lens to customise aberrations or affect the bokeh, including altering coatings, adjusting element spacings, replacing elements and adding aperture masks, but Panavision keeps a firm lid on the actual processes they have devised. Panavision have also recently released an anamorphic flare attachment (AFA) which mimics anamorphic streak flaring much better than fishing line or streak filters, since it uses an actual anamorphic piece of glass (without introducing a squeeze). Those cinemorph filters are about the least convincing methods of introducing anamorphic bokeh, from my observations. Because they only mount at the front or rear of a lens, the oval highlights are often soft edged, cropped or cats eye shaped, vignetting can occur, and a loss of a stop or more of light is common. They often don’t work with wider focal lengths either. A better method is to replace the iris with an oval aperture, which maintains the correct position of the stop and thus accurately simulates both the bokeh shape and depth of field duality that proper anamorphics have. The results from this method can be pretty good. There are online DIY guides that show people simply popping an oval aperture on top of the iris, but be aware that there is often very little room between iris and glass elements and you risk altering element spacings (because the rear group won’t screw all the way back in) or interfering in the iris operation. However if it clears, this method does allow you to use the iris and once stopped down a bit the lens will function as normal again. None of the footage shared by DIY “ anamorfake” you-tubers looks very good though, so I’m a bit sceptical about how well their methods work. The thickness, reflectivity and position of the oval stop are all factors affecting the final image quality (not to mention potential element spacing errors). To get the most out of such a mod, I think it’s best to replace the iris entirely (a reversible procedure). The oval aperture should be laser cut from very thin, matte black material and positioned at exactly the same position as the iris was, and be quite well centred. The oval should be the same height as the wide open iris aperture and half the width, which locks the lens aperture at half a stop under the original maximum lens speed. A variable ND then needs to be used to control exposure. I modified some Zeiss Contax lenses for Sydney-based cinematographer Robbie Fatt (who sometimes posts here) and thought he used them to excellent effect in some of his work:
  4. There are temporal jumps when the flashes occur, which tells you that the film is getting stuck and double exposed. Could be that the transport mechanism isn't working properly (damaged claw, gummed gears, intermittent motor, take-up slipping too easily), or the gate is sticky/catching, or the cartridge could be jamming a bit. It's curious that the 36 fps footage is better - which suggests that the mechanism works at higher speeds, which would point away from the cartridge being the issue, and more towards the camera.
  5. Pin wrenches tend to be larger than what you need, but are often adjustable. A 2 prong driver, or slotted spanner driver, is usually smaller and more useful for this sort of application, but needs to be the correct spacing and prong size. Eg: https://www.amazon.com/uxcell-Magnetic-2-6mm-Spanner-Screwdriver/dp/B07B7L8NHF https://www.wihatools.com/slotted-spanner-nut-driver-m2-6 You may need to round off the prongs with a file to fit in small holes. I often make my own by either filing down the centre of an appropriately sized slotted screwdriver (you need a good small file) or turning a tool on the lathe and fitting 2 steel pins in the end. I would think it's actually quite a rare occurrence.. why go to all that trouble when you can buy another K3 for a hundred bucks? What are you replacing the spring with anyway?
  6. I'm not familiar with this particular iteration of the Zeiss 10-100 (Opton was the brand name that West German Zeiss Oberkochen briefly used when selling products in the East Bloc), but if the zoom ring turns without changing focal length it would appear to be broken. It could be a simple issue, but without seeing and feeling it (or a more detailed description of the actual fault with photos) it's very hard to diagnose. Does the zoom ring turn from 10-100 only? Does it feel smooth? How do you know it's not changing the focal length? The iris should also definitely be capable of manual operation, perhaps by depressing one of the rear plungers, or if there is a switch on the lens itself. Otherwise, possibly the internal return spring of the iris mechanism is seized. I would suggest taking it to a lens technician if you want it properly assessed.
  7. These cameras are pretty valuable collector’s pieces, you might have more luck with antique auction houses rather than eBay. A couple of dozen Parvos have gone for sale in the last 5 years at the auction houses listed in this resource: https://www.liveauctioneers.com/search/?keyword=Debrie Parvo&sort=-relevance&status=archive Finding just magazines for sale will be tricky as they would usually go together in a complete kit. If you can track down collectors who may have bought a kit with lots of mags they might be open to parting with one or two. There are cine camera collector groups online that may be of help. Did you get hold of a Debrie Parvo with no magazines?
  8. Feel free to post pictures and ask questions as you go. I'll try to help if I can.
  9. Normally I’d advise people unfamiliar with lens service to leave zooms alone, but this is an old junker lens by the sound of it, so could be a good one to practice on. No harm done if it no longer works afterwards! Production of this lens ceased decades ago so full technical documentation won’t be easy to find. But it probably wouldn’t help anyway - zoom lens cross sections are hard to decode unless you know what you’re looking at and you won’t find a simple step by step guide to disassembly. The front element lock-ring won’t be a reverse thread, but it could be secured with lacquer, seized or deformed. Try acetone and gentle heat, and be careful not to slip and scratch the glass. In some zooms the front element is positioned with 8 centering set screws that need to be backed off to remove the glass, and then carefully reset with a lens projector on reassembly. Not an amateur procedure. An easier way to access under the front element is often to remove the whole front focussing assembly, which also allows for thread relubrication. You need to remove the stop under the outer focus barrel to unscrew the front, and carefully mark everything for reassembly. With the front off you can also access the front surface of the variator group, part of the moving zoom assemblies. The rear group is probably best left alone, as there are centering and back focus adjustments that need special tooling to reset. Sometimes fungus will have etched into the glass and you can only halt the spread. I use a specific fungicide agent no longer available from Zeiss but there are home made recipes on the net. Good luck!
  10. I very much doubt anything "recent" will work as a replacement. It's likely magazines from other models (E, G, K) would work, or from Askania replicas, etc. It's a fairly simple device, you could possibly manufacture something based on an original, but it would need to locate accurately, have a compatible core, be lightproof and feed or take up the film without scratching. Perhaps a collector with 6 mags might sell you a few?
  11. I think it's the button at bottom right of the black square area on the crank side.
  12. Because the mirror/shutter edge lines up with the expanded edge of the S16 gate aperture, if you don't decrease the shutter angle from 180 to 172.8 degrees you will get smearing along the whole edge of the frame. If you crop it out you may as well not have converted to S16 in the first place. Many people glued a lightweight wedge to the mirror edge to do this, but it needs to be securely fixed and very accurately positioned so as not to scrape while spinning. Typically a job for a trained technician. The magazine conversion is less essential, though there is definitely a possibility that the expanded S16 area will get scratches, scuffs or simply bruising. Again, it affects the whole side of the frame where rollers, sprockets and guides will contact the newly expanded image area, so cropping just gets you back to N16. If you don't re-centre the lens mount you probably won't notice anything drastic with 35mm format lenses except zooms will track off to one side. How are you modifying the gate? If it's not done very competently you will get scratches from burred edges. Don't just use a file for example. If you expand into the area of the left vertical support rail you need to machine that rail down thinner all along its length so that the expanded picture area does not run along it. Google pictures of the narrow left rail on SR3 gates. When I was working on Arriflexes, I would use a jig with a gauge to re-fit the gate so that the aperture lined up with the ground glass, and then use a depth gauge to check and adjust the flange depth to within 0.01mm. Everything on Arriflexes is adjustable, if you take them apart you can easily lose fine settings. Personally I think if you can't afford an already converted S16 SR2 , it's a waste of time trying to convert one on the cheap. A half-arsed conversion will turn what was a professional camera into little better than a quieter K3.
  13. Yeah much better, but notice that the loop formers don't move that far. Sometimes the film can still brush against them as the loop oscillates and you can get scratches. Hard to see but check that isn't happening at the top loop former, and maybe run through a fresh piece of film and examine it for scratches. You can always manually adjust the loop a tiny bit shorter or just remove those loop formers altogether. We still haven't worked out what went wrong with your original footage though. Maybe upload a sample?
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