Transfer of Film

Maybe you still have a lot of celluloid film lying around with old family footage. Well, maybe it will not be there for long anymore, because celluloid slowly degrades over time and all that will be left some day is dust. Our advice, put in on DVD. It lasts a long time, is easy to copy and more convenient for watching. The first step is the most crucial one: digitizing the film. In this article we will look at the options and show you how to do it yourself.

1. Methods

The following methods are available:

Steady Gate System

In this this system, each frame of the original film is scanned and stored individually. This can generate the highest quality, but because of the nature of this process it is very time consuming. Special equipment, built to automate it, certainly speeds up the process, but this equipment is very expensive.

Flying Spot

Already faster and higher automated is the Flying Spot system. In this system the film is transferred along a small spotlight that scans the films in lines perpendicular to the film strip. Specialized equipment exist on the market to do this but at a cost of $10.000 or more, this is also beyond the reach of consumers. It is used by film studio's and also some of the more professional video transfer services may also use it.

Projection

This is the most straightforward method. The film is projected on a suitable surface and then recorded using a camcorder. This method can be done at home and in the remainder of this article we will discuss it further.

2. A note to commercial video transfer services

There are many companies that offer film transfer on a commercial basis. They usually offer transfer to any type of medium including DV tape and DVD. You should always opt for DV tape, because this gives you an easier opportunity to edit the material afterwards both in terms of composition and in terms of quality enhancement. There are significant differences in quality of these services, so if you decide to have it done, make sure that you check their quality. Ask them what method they use and what type of equipment they run. Even good equipment is not a guarantee of high quality. The process itself needs to be closely monitored and settings need to be changed according to the quality of the base material. If they make you feel that they do it as a rush job, this may not be a very good sign. Best of all, try to find others that have experience with using the company that you consider.

3. Do-it-yourself

Cleaning

Important is to start off with undamaged and clean film in a clean projector. If you have not used the film for a long while it may be dusty. Most projectors allow you to wind the film from one reel to another and by doing so while gently pressing a piece of moist soft cloth you can remove any dust. Also clean the complete projector, especially all the optical elements like the lenses. This is best done by blowing off dust with a hair dryer. Only if the lenses contain stains that do not come off by blowing use a soft moist piece of cloth.

Damage Repair

If there are severely damaged spots you better cut them out before running the film through your projector. If the film brakes during playback there is a chance that the film comes to a standstill in front of the light bulb. And since the bulb can become very hot, this will result in burning the celluloid in less than a second. If you need to glue pieces of film together, use the special tools that are available for that ensuring that the pitch between the frames is correct. You should use the special for this purpose designed tape and/or glue but also acetone will do the job.

Use of projection screens

Of course you can use a standard projection screen to project your film. Although this is very good for watching the movie, it is not very suitable for recording because it contains a grainy structure that will be visible on your recording. Better is to use non-glossy picture paper or a piece of paper or a smooth white piece of cardboard. A disadvantage of direct projection on a surface however, is that you will not be able to aim your camera perpendicular to the projection surface. The result is that the image will distort.

A far better option is to use a semi-transparent screen where you project the film on one side and record it from the other side. Because this means that the image will be mirrored you will have to use a mirror to flip the image.

There are a couple of manufacturers who supply special set-ups or boxes for this purpose. We however do not recommend boxes containing simple etched screens. They have a grainy surface and also result in a “hotspot”, a round area in the middle of the screen with increased brightness. The best solution is to buy a special screen manufactured from two sheets of glass with a layer of paraffin in between. Such a screen is free of grains and does significantly reduce the hotspot problem. They may be hard to find, but a manufacturer in Germany is Braehler, who can be found at the Internet under http://www.glasscreen.com/index_en.htm.

Camera settings

Many people love their camcorders because the have automatic settings for everything: focus, diaphragm shutter speed, white balance, steady shot etc. When you do film transfer, best is to put everything on manual.

• Focus: on manual. Changes in luminance on the screen may fool your autofocus, causing it to change focus
• Exposure: on manual. If your camera has a very good quality automatic exposure mechanism, you may want to try that. If you notice that your camera starts over-correcting when the brightness of the film changes, you better use manual and make careful manual adjustments during the process.
• Steady shot: disable. This feature will reduce the number of effective pixels, so you should disable it. It is not necessary anyway, because we assume that the camcorder is going to be on a fixed position.

Flicker

A very well known problem when transferring film to video is flickering, meaning periodic change in brightness.

Standard frame rate of video these days is 25 (PAL) or 29.97 (NTSC) frames per second. Because video consists of two fields (one for the even lines and one for the odd lines), the actual "captured images per second" is 50 (PAL) or around 60 (NTSC).

Film is usually made at either 18 or 24 frames per second. All film projectors project each image two or three times. The number of projections per second times is determined by the number of blades of the butterfly shutter in the projector. Projectors for film at 24 fps have 2 blades, so the number of projections per second is 48, projectors for film at 18 have 3 blades, so the number of projections per second is 54.

Because of the differences between these numbers, the recording will show a slow flicker. In order to avoid it the recording speed should exactly match the projection speed (or the ratio between these speeds should be an exact integer).

One way to achieve this, is by increasing or reducing the projector speed. Many projectors will have some kind of speed control, but if that don't or the range is insufficient, you can make changes in electrical power supply or change diameters of one of the pulleys that drive the belt in the projector. Disadvantage is that you actually change the speed of the events in the movie, although in most cases this will hardly be noticeable.

Another, more elegant, method is removing the flicker with by editing the video digitally. And again, the good old freeware program VirtualDUB can be used for that. Various free deflicker filters are available for VirtualDUB including Donald Graft's Antiflicker filter which can be found from his website at http://neuron2.net/ or the MSU deflicker filter, found at http://compression.ru/video/index_en.htm