Many older people or their heirs still have reels with films of family archives on 8 mm film, on which home movies are recorded. In order not to lose this value, they try to digitize them, preserving the memory of the past.
For this, it is necessary to produce high-quality digitization of 8 mm film, which will minimize the loss of frame quality. How to do it? How to digitize film at home? To do this, there are several methods described below. They are distinguished by the complexity of execution and the quality of the output image.
What is the device for digitizing 8 mm film? This will also be described in detail in the article.
Technical base
To digitize film, you can contact one of the video stores, where they perform similar work. True, it will cost a lot: it’s not a very standard service, which is purchased several times a day, moreover, it is a rather laborious process.
Another option to transfer material from film to disk is to do it yourself. All that is needed is a detailed plan of action and a working apparatus (for example, the film projector "Rus").
There are several methods of digitizing the film, among which:
- screen capture;
- frame-by-frame shooting;
- Lens-to-lens shooting.
Next, each of the methods will be considered in more detail.
Screen capture
The essence of the method of shooting video from the screen is as follows: a movie projector projects an image on an impromptu screen, and a camera located somewhat to the side takes it.
To implement the method, the following conditions must be met:
- Shooting should take place with absolute dimming from a distance of about 2 meters from the screen.
- The projector should project an image from a short distance onto the screen.
The camera can be connected directly to the computer so that the captured image is transferred to its storage. This will save the original format and not lose quality.
To use this method of digitizing 8 mm film, you do not need to modify existing equipment (film projector, in particular) or change the format of the output video. And without that, a copy of the original image is obtained.
Practical implementation
Film projectors are now quite rare, you can find them in any archives or in schools in which the old material base has been preserved.
Facilitates the task of the fact that with the resulting projector does not need to do anything, make structural changes. Unless you need to replace the straps (drive belts), which could crack from time to time, and grease them with silicone grease. It will not be superfluous to clean the dust and lubricate the film projector itself.
The role of the surface onto which the image is projected can be performed by either a large paper sheet (the main thing is that it is not glossy), or a sheet or a special screen. Of course, you can also project video onto a white wall, in which case it should be as flat as possible, without obvious bends, cracks and other defects.
The projector lens and camera are specially positioned a short distance from the screen to increase image clarity and not lose color saturation. The farther the camera is from the projected surface, the lower the resolution of the final image.
An important criterion for shooting directly from the screen is the maximum coincidence of the optical axes of the camera and the film projector. The smaller the angle between these axes, the less the picture taken by the digital camera will be distorted.
Due to imperfect coincidence of the axes, the colors of the image may be distorted. The part closest to the camera will be brighter than the distant one. To eliminate this drawback is almost impossible, because working with lighting is a very time-consuming process.
Digitized image transmission
You can take any camcorder to take the image projected from the projector. The cameras of tablets, smartphones and even digital cameras are better not to use, so as not to lose picture quality.
The best option is a digital video camera. It creates files in a format that can immediately be transferred to a computer without loss of quality.
You can, of course, use analog video cameras. In this case, the process of transferring files to a digital format will be noticeably more complicated, because the image from such a camera will need to be digitized using a tele-tuner or using a device for digitizing video tapes.
Moreover, shooting with an analog camera will never turn out to be very high quality, because interference will always be introduced into the image. That is why it is preferable to use a digital video camera immediately.
Disadvantages of the screen capture method
What are the disadvantages of this method?
First of all, low image quality. Despite all the tricks with the light, optical axes and the equipment used, the use of this method will never allow you to get the highest quality image on which defects are not noticeable.
Types of defects:
- Flicker. Since the photosensitivity of the video camera is much higher than that of the human eye, flickering is visible on the digitized image. The camera manages to take the moment of the frame change, which is not visible to the eyes of people due to the presence of a special device in the movie projector, which is called the shutter.
- Exposure setting. Digital cameras automatically adjust this setting. Many do it in a split second. With standard shooting, this fact only improves the final image. When photographing an image from a film projector, this only interferes, because the camera analyzes not only the image itself, but also the black screen that appears when changing film frames. Because of this, brightness fluctuations occur in the digitized image.
The presence of these defects prompted specialists in digitizing 8 mm film to invent a new, more efficient method.
Single shot
It is possible to achieve perfect smoothness and image quality if each frame is shot separately according to the formula “1 video frame = 1 film frame”. This is the essence of the method of frame-by-frame digitization.
True, its technical implementation is more complicated than the previous method of film digitization, because it is necessary to solve the following problems:
- The difficulty of capturing a frame at the time the film stops.
- Overheating of the film during a long stop or slow web movement.
To eliminate the first problem, it is necessary to constructively improve the film projector. To do this, a small sensor is installed on the projector shaft (rotating part), which plays the role of a switch. It sends a signal to the computer to capture the frame at the right time. This allows you to synchronize the moment of capture.
A problem may occur when configuring the sensor. For his work to be correct, you need to remove the obturator from the movie projector. Thanks to this, the frame capture time can be increased by almost 3 times.
Film overheating
To achieve maximum shooting quality by the single-frame method, it is necessary to achieve a minimum film speed: from 10 frames per second or less. The slower the web moves, the more it heats up. This significantly spoils the film. Great risk of breaking it.
In fact, projectors provide protection against overheating. For this, a heat filter is installed in them, which blocks the projection of the image (lamp light) if the speed drops to 5 frames per second or lower.
The problem is that it is about this speed that you want to shoot with the single-frame method. Therefore, the heat filter must be removed. True, nobody canceled the issue of protecting the film. It can be saved from overheating in the following ways:
- independently control the speed and turn off the lamp when an unplanned stop;
- install additional cooling, for example, in the form of a fan;
- replace an incandescent lamp with an LED that emits the same power light, but has much lower heat loss.
As a fan, you can take the cooling device from the system unit of the computer. It will be enough to control the projector in manual mode.
Principle of operation of the shift sensor
The switching sensor is a device that transmits a signal to a computer for capturing a frame and to a shaft for rotating it. It can be taken from a computer mouse.
The principle of operation of the sensor is as follows:
- The sensor transmits a signal to the computer.
- The computer captures the frame.
- As soon as the frame is captured, the shaft changes its position.
- The frame changes and the sensor sends a signal to the computer again.
Programs for capturing frames on a computer are freely available. Examples of such software are Bandicam or Fraps. True, for the correct capture operation, you will need to output the sensor signal contacts to a computer mouse.
Shutter removal
There are two ways to get rid of a shutter:
- gently unscrew it from the projector;
- cut off the blades that block the light from the lamp.
The latter method is much simpler. For its implementation, only scissors for metal will be needed. However, after removing the blades, using the projector in normal mode, that is, without flickering frames, will fail.
Once the necessary improvements to the film projector are completed, you can proceed to capture the image from the film and digitize it.
Digitization method “lens-in-lens”
The essence of the method is to install the camera close to the lens of the projector and shoot the image in this way. For its implementation, minimal structural changes in the projector will be required, namely, it will be necessary to change the lamp to a less powerful one.
The latter is made for reasons of reducing the luminous flux: the higher the luminous flux, the better the projection at a farther distance, but in this method the distance from the projector’s lens to the projected area (camera lens) is minimal.
Installing a camera and film projector
The projector and video camera must be installed on one rigid structure, which will make it possible to change the position of the projector and camera in space (this is required in order to combine the optical axis).
Lens used
The lens used with this method of digitizing the film should be short-focus, because the distance at which it needs to focus is very small. A lens from any telescopic system or even a macro lens will do.
Digitizing a black and white film
If black-and-white film is being digitized, then a light filter must be placed between the camera and projector lenses to prevent the appearance of a vignette. It is better to install an interference filter, but the standard red is also suitable.
Method Features
When using the lens-to-lens digitization method:
- shooting is carried out at almost normal speed and overheating is not terrible;
- projection speed will be reduced to 5 frames per second, only if the projector is well warmed up; if the projector is in a cold state, the speed will not decrease;
- a cold projector will not start at low speed; it is better to set this parameter immediately to the average value, and then gradually lower it.
It is difficult to determine by ear the moment when the projector speeds up. To do this, you can record sound and compare the audio track with the one that was recorded during normal operation of the movie projector.
Conclusion
Of course, there are many methods of digitizing videotape, but those described in this article are most often used, so it is worth highlighting the advantages and disadvantages of each method.
Advantages of the screen capture method:
- ease of shooting;
- no need to constructively change the projector.
The disadvantages of this method are:
- poor image quality compared to other methods of digitizing 8 mm film.
Advantages of the method of frame-by-frame shooting:
Disadvantages:
- the possibility of overheating the film;
- the need to seriously upgrade the film projector.
Advantages of the lens-to-lens shooting method:
- high image quality;
- low probability of overheating of the film;
- no need to make major changes to the design of the projector.
The “lens-in-lens” method does not have significant shortcomings, therefore it is the most optimal in order to digitize a film.
Thus, it is not at all difficult to digitize a film at home on its own. The main thing is to follow the tips described above. Although, if there is a risk of spoiling the videotape, it is better to entrust the matter to professionals who know how to work with such material.
It is to be expected that a considerable amount will be required for such work. For example, in Moscow, a minute of material in HD-resolution can cost about ₽350, so in some cases it is easier, cheaper and faster to digitize the film yourself, without the help of specialists from various video salons.
In addition, this is a rather interesting process.