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Telecine Old Wives’ Tales Examined |
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1. “You get a sharper transfer if the camera looks at the sharp side of the film instead of the soft side.” WRONG! (Usually.) The film emulsion (which carries the image) is coated on a crystal clear plastic base. The picture looks exactly the same from either side, unless the film base has in effect been sandblasted by unusual abuse, giving a sporadic diffusion filter effect when viewed through the base. You can test this yourself by looking at both sides of normal film with a magnifying glass, or flipping the film and projecting a still frame. The sharpness looks the same either way. If severely manhandled film also has a very deep scratch the image past the scratch will be distorted a bit viewed from the base side, but this is masked by the distracting scratch itself and so is of little consequence. We might point out here that every 35mm movie print you have ever seen in a theater, and all currently made 16mm prints contact printed from negative, are shown with the base side towards the projection lens. If this routinely caused any quality problem, the situation would have been corrected 100 years ago. In the case of color negative film, actually the emulsion side is the soft side! It is purposely made with a microscopic surface texture above the image layer that prevents Newton’s Rings from appearing in a contact print. The base side is perfectly smooth however. If someone makes wild exaggerated claims about the supposed superiority of emulsion side scan, you should tell them to prove it by a direct comparison. We do have emulsion-side scanning of original 8mm and super-8 film available for folks to whom this is an issue, or thinks it is, in our True Speed and Mainstream E models.
2. “You can make any projector a telecine by just putting in a 5 blade shutter.” RUBBISH! For one thing, many projectors have too slow a pulldown cycle for this many blades and will give “travel ghost,” which is vertical streaking of the image. Besides, a 5 blade shutter is only correct for transfer to NTSC video at 24 FPS or to PAL video at 20 FPS (frames per second.) Besides, most consumer film was shot at 16 or 18 FPS and the 24 speed will give a “Keystone Kops” inadvertent comic effect. Besides, even with the right speed and right number of blades, the speed must be accurate within 0.1% or less to avoid shutter bar or flicker, and the average projector runs a few percent off-speed, usually fast, and it varies according to the size of the reel, the line (mains) voltage, and how long it has been running. For adequate speed accuracy, the telecine machine must have either an AC synchronous motor or a crystal motor, together with gear or timing belt drive. Besides, the optical system is wrong and lacks the needed source diffusion to avoid hot and dark spots in the image. Unless, that is, you are projecting into one of those nasty little groundglass boxes, which presents a whole range of new defects. (See part 4 below.)
3. “Pause the film and shoot one frame at a time for superior quality.” BALDERDASH! A normal projector mechanism gives plenty of time to capture the images when running at normal speed, if it is done correctly. Your eye is not able to appreciate it, but in normal speed running, the film is already perfectly still in the gate some 80% to 90% of the time. The remaining 10% to 20% of the time the film is being pulled down to the next frame at 5 to 10 times the average speed. So at 24 FPS for example each frame is completely stationary for about 1/30 of a second. The video camera can get a perfectly fine grab of that frame in far less time, such as 1/125 to 1/500 of a second. It only remains for the film movement to be correctly synced to the video camera for this to work, as is successfully and reliably done in our TVT equipment. In low-tech computer-dependent competitive equipment, they are forced to run the film slowly into the computer, then the user has to go through the computer file of the film again to render it at correct speed, and they try to “spin” this disadvantage into an imaginary advantage. The only thing that is accomplished really by all this “slaving over a hot computer” is making the process slower and more difficult, greatly reducing (by about half) the amount of money the user can earn per hour. Or else the operator will have to charge an exorbitant non-competitive rate per foot.
4. “I can use a “telecine box” and save lots of money transferring the film myself.” HA! Anyone who has ever tried this is likely still laughing at this remark. The many units for sale at low prices up on Ebay, mostly never actually used because the previous owner gave up in disgust, is a testament to how difficult to use and technically worthless these devices are. The image quality is bad. There is a grainy little screen that makes the image look like it was being projected on to a concrete wall, in the unlikely event that the setup is accurate enough to make out such detail as the grainy ground-glass or the picture being projected on it. There is a low quality uncoated plastic “Coke bottle bottom” close-up lens to guarantee an unsharp picture. There is no field lens to brighten the image corners and eliminate the center “hot spot.” There is a low quality metalized plastic mirror that is likely not perfectly flat, causing distortion and unsharpness. The projection lens is optimized for near-infinity screen distance and will not be as sharp close-up, and the wide f/1.6 aperture makes focus very critical with a tendency to drift. As if that isn’t enough, the basic principle of operation is deficient. The problem of flicker (because of differing film and video rates) is not addressed at all, or is only spoken of in a footnote, once you have already bought it and didn’t know until too late that your projector type is useless for the purpose, so usually there is an irritating flicker and pulsation that could cause an epileptic fit in susceptible people. Not only that, but the mounting is flimsy plastic that wants to vibrate, sag out of position and shift out of focus. It is very likely to result in “keystoning” or bad geometry where one side of the image is larger than the other, and both edges are out of focus. This makes things even harder when you are trying to balance the box and the video camera on a pile of books or bricks to equalize their heights to that of the projector. Don’t be fooled by the “deluxe” models bristling with jacks, knobs and switches. These are only for sound mixing, and do absolutely nothing about the optical deficiencies or flicker. In fact, if you make the mistake of touching any of the knobs while running, you will bump the unit out of position and spoil the transfer even more than it already is.
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