Movie film transfer info

From time to time I'm asked to transfer 8 mm or 16 mm film to video tape (or disc), and asked why it doesn't look quite as good as the original film (likewise for transferring still transparencies, or “slides” to video).  Actually, this is normal, as they're two completely different mediums (film and video), with different capabilities.  Though, having said that, film transfers can look a lot better than some that I've seen done.

Our transfers are quite good, enough that I get referrals and repeat customers who're very happy with the results.  We use the projection technique; we project onto a small screen, close to the projector, for a bright image, and use a professional triple-CCD camera with a fully-manual lens to film the projection.  This produces much better results than you could do with most home video equipment (with fluctuating auto-iris, auto-focus, auto-white-balance, much poorer lenses, etc.).  You can get even better results by using a film “scanning” service, where the film is scanned rather than projected, but you'll be paying quite a lot more than we charge.

NB:  Although this sort of thing is commonly called a “transfer,” it's really only a copy.  The original film or slides are copied, not moved, the image isn't really “transferred.”

Why doesn't the video look as good as the film?

Film has a much greater contrast ratio, meaning that it can show a wider range of levels between black and white.  Also, film handles over and under exposure better.  When converting to video, either some of that range is lost (e.g. dark things become black, and disappear in the shadows; and/or bright things become white, and become lost in the glare), or the video signal must be compressed to fit the film's range into video's (expensive, and difficult to do right).

Film also has a much greater resolution than video, even old 8 mm film (though it has to be shot well, to achieve it).  Moving film is made up from an infinitely varying collection of dots, giving virtually infinite resolution; though the size of the dots, and the quality of the lenses, are limiting factors.  Standard video would never look as good as film blown up to screen sizes used at cinemas, because it's made from a fixed number of lines, or pixels; and not many of them, at that.

Film has a different colour response.  It can handle a wider range, better.  Film can handle some changes to colour temperature, showing them as they are, and let your eyes adjust as they do normally, before compensation has to be used (colour correction filters on the camera, and/or colour grading while processing).  When transferring to video, it's much more necessary to compensate for changes from the norm, so that pictures don't look excessively red or blue.

Why do films shown on television look okay?

They're generally converted to video using exorbitantly expensive equipment that has the ability to nicely compress the contrast range to suit, and the films are colour graded properly, in the first place.

Professionally shot films are shot well; they rarely have under or overexposed shots, and they're in focus.  Please don't compare multi-million dollar productions with your $18 home movie film.

Can you improve the picture?

Generally, “no”.  You can't make an out-of-focus picture to be in-focus, and artificially crispening the picture doesn't help (in fact, it makes things look much more of a mess).  Over- and under-exposed shots are “over-” or “under-” exposed, and you can't fix that up.  Very highly contrasty shots will require adjusting the video exposure to either make the brighter aspects of the picture more viewable, completely losing anything that's moderately dark; or over exposing the video to show some of the darker detail, completely washing out anything that's bright.  Shots with badly faded colours due to time, film and processing instability, and poor storage, can't really be compensated for.  Shots with out-of-range colour temperatures can be compensated for, to some degree, but having to continually adjust the image is very labour intensive.  And the transfer process works by re-filming the film with a video camera that probably has a different spectral response than the original film.

Why are some things cropped off the edges?

Much of that depends on your TV set, as well as how you've shot the film (not leaving a bit of space around the edges of what you're filming).

Television sets typically project their picture past the edges of the tube, so that you don't see the entire picture; some sets over-scan by as much as 20%, though modern sets are typically around 5%.  Whereas, most people project their movies onto a screen where they can see the entire frame (many cinemas do mask out the edges of the picture, so that you see straight edges to the film, rather than fuzzy or trapezoidal edges).

When I transfer films, I frame them so that their image fills the entire video frame, right to the edges.  I could zoom out, so that there's a bit of a blank border around the frame, but on some TVs that'd be very noticeable, on others it wouldn't be enough.

Why is the speed of the action different?

Movie film and video run at different frame rates.  Australian PAL video uses 25 frames per second, normal film runs at 24 frames per second, necessitating either a small increase in the playing speed to match (which usually isn't noticeable), or digitisation and merging of some frames together, to fake an extra frame per second (which frequently looks bad).

Home movie films usually ran at 18 frames per second, giving you three possible ways to transfer them to video:

The third option is what's generally done.

As a point of interest, the original silent movie films were usually run at around 16 frames per second, but the cameras were often hand cranked, and varied somewhere around that speed.  About 16 frames per second is the minimum rate needed to show pictures which seem to be moving (moving pictures are a “trick”), but around 25 frames per second is the minimum strobe rate before the eyes stop noticing that movement is flickering, so that's the speed that things are filmed at, these days.  And since it's nearly double that rate before the eyes stop noticing light has a flicker, most projectors strobe each frame twice, or more, so that the apparent frame rate is faster.  (See persistance of vision.)

Why is it so expensive to do?

Mostly because it's labour intensive, as well as the video equipment being expensive.  Film transfers require constant monitoring, frequent manual adjustments to exposure (automatic iris control doesn't work well when filming flickering light sources, and very contrasty films require a choice about whether to concentrate on the darker or brighter aspects of the shot), and usually involve a lot of spool changing, or repairs to very old splices.

Is it worth doing?

That's subjective.  Films look better when shown in their original medium, though many people have old or broken down projectors, and it's a lot easier to take a video tape around to someone else's place, than a collection of films, the projector, and a screen; as well as not having to black-out a room, and not having to put up with the noise of the projector.

Can I do it myself?

Yes.  But to do it well you'd want a video camera with manual focus and exposure, a projector with variable speed adjustment, and some way of muting the microphone and/or directly feeding sound from the projector.  Project the image onto a small white screen, close to the projector so that it's bright.  Place the camera as close to the projector as possible, so that you don't film from an angle (filming from the side would give you a stretched image).

An alternative to projecting onto a small screen, is to use a prism box (you aim the projector and the camera into it, and film through it).  Some of those prism boxes aren't too great, though.  Some don't reduce the amount of light enough, so the camera is virtually looking directly at the projector's globe (you really need a modified projector for this to work well).  And some project through a screen, which can make the images very murky and fuzzy.

Can you add a sound track?

Yes, though bear in mind that you have to pay dearly to use any copyrighted material.


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