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Robert Hart

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  • Occupation
    1st Assistant Camera
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    Perth Australia

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  1. What happened I wonder. Were they expedient, unthorough and :- failed to check the wind of the film before scanning? flipped the film to scan though the base to avoid false triggers from splices or avoid an eroded emulsion surface which was defeating the triggering system then forgot to flip the image in their post work? Things happen like somebody interrupting for advice and distracting the operator from task.
  2. I wonder if once you have a safety copy scanned off the film and the owner of the film consents to possible loss, that you could bleach the base face of the film and wash/wipe the bleach off before it can touch the emulsion face. I would be inclined to still try adding a green gel filter to your scanner's backlight source to balance the magenta. The ghost image may however remain as a faded black and white image. You have a conundrum there that I do not envy on little bit.
  3. Andrew. If you could get hold of some green lighting gel, probably about 1/8 or 1/4 and place that over your light source, that might be helpful in bringing the blue and red channels back into balance if the magenta masking in the base is consistent in density.
  4. Is it by any chance a Nikon F-Mount to CP-Mount adaptor with a small planar glass element inside? Aaton Mount and CP-Mount apparently have some similarity but the Aaton shoulder diameter may be wider.
  5. It was not uncommon for wow and flutter to occur in syndicated music under commentary of 16mm documentary films. The fidelity of the commentary is really quite good for 16mm. Because wow and flutter occurred in film projectors as well, people may have cared less about it and let it through. If you still have the film, perhaps take a scan of the image and soundtrack and use AEO Lite to reconstruct the sound track. That should tell you if the film's linear speed was not stable through the sound reproducer of the Lasergraphics machine.
  6. It is not the parts themselves which may or may not be all store-bought but the sum of all the parts and the application they are directed to which form a registerable design.
  7. It is rather a pity. With careful fine adjustment, the transport and frame triggering can be very stable. Like all scanners, it can become a troubled child when old and damaged film is scanned. Mechanical reliability related to the original electromechanical unidirectional clutches and the first in-house purely mechanical replacement clutch which also failed in service brought the enterprise low. One hopes that competing manufacturers do not harvest the proprietary IP from the bankruptcy administrator just for the anti-competitive purpose of burying it. If owner-users want to preserve some level of product support, then they may need to bite the bullet and club together to bid for the IP, proprietary registered circuit/hardware designs and CAD files. The basic system has good bones but some achilles heels as well.
  8. An option out of left field might be to find an old groundglass-based 35mm film-image emulator like a Letus Extreme or a P+S Technik Mini35-400. They used to come with rails, tripod mount bases and bridge-plates. It would require much adaption and you likely would need to use a 75mm prime lens. You could then use stills 35mm film lenses in Nikon, Canon or even PL-Mount in some instances. You would still need to crop top and bottom of frame or add an anamorphic adaptor for a cinemascope look. Your depth of field will be quite shallow. That was often a signature of users who went for razor thin depths of field not because they should but because they could. A Mini35-400 resolves between the old standard definition TV and JVC's flavour of HDV. A Letus35 Extreme can be tricked up to resolve a little better and if significantly modified achieve near to 35mm full frame and 2K. Your would lose about 1/3 to 2/3 f-stop of light and with tighter apertures than f5.6, some nasty artefacts begin to appear. I tried it for kicks with a CP16 16mm camera with this rather unscientific test and a sort end of 16mm film, The letters DTC mean direct to camera, that is without the groundglass adaptor in the optical path. .
  9. If you dry-run the Bolex without film going through, please do not run it until it stops. In an unloaded state, the inertia in the film transport, especially at high frame rates may drive the spring and damage it. When you button off, make the movement quick and decisive. If the run button is released slowly, there will be a clattering sound and there will be several light frames. The mechanism inside can cope with it but it is best not to have that happening.
  10. I have had the piece of aluminium stock sitting in a 4-jaw lathe chuck to make the heatsink. To restore back-tension which I had backed off as much as I could when using the pressure plate for 16mm film, for an unexpected 8mm task, I resorted to some primitive bogan engineering with a piece of foam stuck to a piece of flatbar with a felt rubbing strip and around it. I carefully chose the book thicknesses to stack to stop the flatbar from moving across but add no extra pressure. It was that or pull the outfeed motor assembly out of the cabinet and upset my careful 16mm back-tension adjustments made when setting up the pressure plate. Extreme care is needed to avoid overloading the take-up motor/transmission and the old style electro-mechanical clutch. Andrew Wise and myself have had separate notions of how to implement a mechanical load-sensing arrangement for constant back-tension with a swingarm and brake band around a hub similar to old analogue audio recorders. The challenge is to make it fit around the exiting hardware and play nice without requiring things to be cut and changed.
  11. This is the COB LED that Dan Baxter pointed me to. https://store.yujiintl.com/collections/led-cobs/products/yujileds-cri-95-50w-cob-led-3200k-5600k-400l This is the setup for the COB LED lamp powered and controlled independently of the Scanner's own electricals. My own arrangement was for convenience and avoidance of an extra set of cables for some fool like me to hang a stray toe in with a double bonus of damaging the cord and stretching me senseless on the floor. For a heatsink I have a temporary piece of finned heatsink trimmed down to fit. I intended to replace it with a more robust heatsink styled after the one in the accompanying image. It appears to have been made up from broad and narrow washers stacked with two long machine screws to hold them all together. My guess is that there will be thermal compound in between each of the pieces and under the COB LED. The heatsink would have to be made for you as a custom job. I think you will find that RS Components will have the LED driver box and the 50W laptop powerpack. For a pot, I do not know the values. I just grabbed one out of a parts box I had handy and used that before using the control source from the mainboard of the scanner.
  12. Following some generous advice from other contributors here, I made some improvements. To upgrade the lamp will require another power source for the lamp driver. I had a few old PCs which had laid down but had perfectly good power supplies. Some can be tricked into supplying power by linking a switching circuit that the motherboard of a PC normally energises. Other cannot without some serious innovation beyond my meagre abilities. I used one to supply power both to the scanner and to an LED driver. I installed it within the rear of the cabinet with suitable venting for it. Be aware that installing anything high voltage which can incinerate itself when it fails is not a good thing to have within wooden cabinetry. The manufacturer of the Retroscan sensibly avoids that risk by using a remote power supply. Whilst I originally used a separate pot to control the light level, I found that I could use the controller output from the scanner's main board itself. I did not draw power for the LED driver from the main board. I bought and installed a 4K FLIR camera and use the Spinnaker Spinview application. The camera is not seen by the Alteraware app which is custom for the 2K scanner. For my capture PCs limitations and the USB3 connection, the frame rate has to be reduced to below about 9FPS. The camera seems to present its full 4K dose of sensor data even if the sensor is windowed. The speed controller was going to be a harder nut to crack. An innovator with the Mark 2 in the US suggested a simpler solution, that of adding a powered motor controller in series on the power line to the take-up drive motor. That has worked fine but there is a frame rate increase as the wind diameter on the take-up reel builds. The machine is no longer a set and forget proposition but requires monitoring and several adjustments of the transport speed of the film during a scan run. For mildly shrunken and warped/cupped film, I found that a pressure plate which spans the fixed guides and attention to the back-tension on the film is adequate to maintain the film at the light pin's adjusted focal plane. For the 35mm film, smaller diameter rollers each side of the "gate" are desirable as the film is bent acutely at the fixed guides with the larger rollers. The downside of smaller rollers is less inertia therefore slightly less stability of the film speed through the gate. A workaround for mildly warped film is to shim the outfeed roller so that a lateral tension is applied downstream of the outfeeding fixed guide and tends to destress the film edge under the light pin and move the ripple to the opposite edge. For film which has been cleaned too many times and the emulsion face has become less reflective, it may be necessary to flip the film during a rewind so that the reflective base is seen by the light pin. With care, film can capture nearly if not as steadily through the Retroscan as any other but of course on-the-fly electronic steadying offered by other products is not available. Things fall in a heap when a splice or sprocket hole damage visits and passes through. Some things you just have to be prepared to pay for.
  13. You did very well to get those greens and blues back. As for stabilisation in Resolve, I have never been able to make it work on sprocket hole edges. I think the horsepower of my PC is the issue. It will analyse about five seconds of footage then gives up. It would not be impossible to build a proper wetgate for the Retroscan as the geometry of the film path is favourable. However, the lightpin edge detector would have to be moved as it relies on surface reflectance which is not available from the film within the wetgate tank. The further the light pin is away from the actual film "gate", the more disrupted the sequence of images becomes as splice interference occurs much deeper into the sequence of frames after the splice goes though the gate.
  14. Here is a link to a test with surface wetted film which worked better when the shiny base of the film was presented to the light pin sensor. Sprocket hole registration is still not as steady as when film is dry. You will observe some patching and banding from earlier successive dips of the film when the material had not flashed off before the film wound onto the reel. The effect of cupping was reduced when the film went over shiny side up.
  15. It is not particularly newsworthy or an innovation but I tried making a dip-tank for surface-wetted scratch reduction when scanning 15mm or 8mm film with a Retroscan Mark 2. I was using isopropyl alcohol of claimed 100% purity. It did work but also tended to destabilise the sprocket hole registration. At more than about 7FPS with 16mm, the material was not drying off before it entered the take-up wind. It is also not benign when it comes to film emulsion. After something like about ten tests with some old print film, I discovered that the base material was cupping and the glazed surface of the emulsion was becoming opaque to the light pin edge detector. I guess Film Fabriek experimented with full immersion, discovering the pitfalls before going with wicking pads to coat the film more sparingly. Once the emulsion surface has become dull, the film has to be flipped so that the shiny surface of the film base faces the light pin and edges of tape splices do not set off false triggers. In this instance, I was running the film from right to left on the top of the reels to present the shiny base to the light pin detector. The small knob under the dip-tank is not related to the dip-tank but a speed controller which is not original manufacturer's equipment. My PC hardware and the USB path does ot cope well with the frame rate when capturing with a 4K FLIR camera.
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