Film Transfer Methods

Different Transfer Methods - Shoot Off The Wall - Aerial Image
Direct off the Emulsion - Real time - Frame by Frame

Real Time - Off the Wall

The first film transfers to video we done by projecting the film onto a white screen and then simply aiming a video camera at the projected image and after focusing, simply hitting record..   That was it !  The ultimate in simplicity !   One could actually transfer film to video that way and it would be quite watchable.  Aside from flicker and merged frames (more on those topics later), shooting off the wall as it was termed, had two major drawbacks. One easily solved but inconvenient for the transfer technician, and the other one insurmountable, for the sole reason that it was a capture off of a white screen.  

The first problem was that the transfer had to be done in a completely darkened room to avoid any ambient light contamination from washing out the image to be captured.  However, this meant often working in the dark or continuously flipping on and off the light switch to see what one was doing..   But in any event, it was easily surmountable.

The 2nd problem with "Off the Wall" transfers was not resolvable...   The problem was light spillage..  The screen by it's very nature had to be a smooth reflective white surface.  The problem with white reflective surfaces is that they simply reflect !   They reflect not only the image both we and the camera "sees" , but also reflect horizontally bright areas on to adjacent less bright areas..   There is no beating it.  That's what reflective surfaces do by definition..   Thus image captures done this way tend to appear to be slightly more  lacking in fine edge detail.

Real Time - Aerial Image / Shoot directly off the Emulsion

The next major improvement was to overcome the limitations of capturing a projected image off a white reflective surface.  There are two ways to accomplish this. Both entail effectively shooting off the back lit film itself. This all but completely eliminates any light splatter or external light contamination due to ambient room lighting.

The first method is to employ a mirror and large condenser lens.  Since we are imaging effectively directly off the film, the image would be horizontally flipped if we just aimed a camera directly at the film.  The mirror flips the image horizontally so that right appears to be right, and left appears to be left.  A condenser lens is nothing more than a glorified term for a magnifying glass.  8 and even 16mm film makes for tiny images, and to fill a video screen we must be able to zoom in or enlarge the image.  A large condenser lens fits that bill..  Since glass transmits light and mirrors only reflect in one direction (remember all those wonderful high school physics classes where "the angle of incidence is always equal to the angle of reflection" ? - Well; here it is in action !   By looking at the reflection of the image off the mirror through a condenser lens, we are just as effectively looking at the backlit image off the film itself.. 

The other way to accomplish the same thing is to scrap the mirror and condenser lens and simply aim the camera right at the backlit film itself...   It means that the image will be mirrored since we eliminated the mirror to correct this, but this is easily flipped back in image processing software.. 

The two methods produce the same results. The 2nd method that eliminates the mirror and condenser lens does require a special macro lens to allow the video camera to zoom in to the full frame of film..  The advantage of this is that the system can be made extremely compact, with no chance of external light contamination or troublesome reflections.

Frame by Frame film transfer offers some unique advantages over real time. 

First: absolutely zero flicker due to the disparate frame rates between film and video. Each frame of film has  a separate image associated with it,  No more merged frames !

Second: vintage Regular8 and Super8 silent movies were often shot at 18 or 16 frames/second.  Frame by Frame captures can then be played back at almost any speed without any flicker so that motion appears normal, without the "Keystone Cops" effect of motion being at hyper speed.  Some cameras even allowed the option of shooting at 12 or even 9 frames per second..   It appears slightly "jumpy" due to the low frame rate, so why would anyone opt to shoot at those speeds ?  Other than for artistic reasons, the main reason was that you could film for twice as long at 9 fps compared to 18 fps..

Third: The film drive through the projector is sproketless. That is a major advantage in handling older films that have become brittle. Sproketless designs are simply far gentler on the film and impose far less wear and tear to the sprocket holes.

Third: Since the frame rate during capture is much slower, the film tends to be much more stable and accurately positioned in the film gate.

Fourth: The film gate itself is enlarged, allowing full  view and capture of the frames...

For these reasons, it is technically the preferred way of transferring vintage silent films..  The quality of the transfer is simply provides better results than any real time methodology...    It is the same system used to Telecine Hollywood film for broadcast.

The tradeoff is that it takes far longer..   The projector/camera advances  less than half to quarter speed of a real time transfer, advancing slowly frame by frame to create a series of still images, each with it's own filename..   Software later allows these individual frames to be combined into a motion avi movie file, but this requires processing time to calculate the correct pull down, which means even more time..    Only then can the capture be imported into a video editing system, where titles are added and corrections if warranted are made.  The completed movie is then rendered and output to DVD, BluRay or even a data file.  This takes  even more time, but the results are always better than doing real time transfers...   As the old saying goes: "Good - Fast - or Cheap: Pick any two !

Sound film for obvious reasons must be transferred at normal speed.  Generally, this is always 24 frames per second which was adopted as an industry standard for all sound films..   Since 24fps x 5 using a 5 blade shutter is 120 which is an even multiple of video's 30 frames per second, the sound capable telecines all employ a 5 blade shutter that chops each frame up into 5 "pieces".  5x24=120 which is a nice even number divisible by the 30 frames/second for video.  Ergo: the transfer will be flicker free ! There is however a technique we use that satisfies both..  The first pass captures the audio at normal speed, and the 2nd pass is done on a frame by frame capture Telecine..  The audio is then aligned with the video during editing..  Naturally this more than doubles the time involved and aligning the audio to the video although not "rocket science" can be a bit time consuming. But where the absolute best  quality is called for and cost is not a major concern, it offers the best way of transferring sound films...  For some priceless films, it is warranted...   But for most sound transfers, the final quality is still quite acceptable, the transfer will also be virtually flickerless, and the cost is far less...

When are the only times that Frame by Frame transfers will appear to flicker ?

In short: filming off a TV Screen or from another projected movie film.

Many people tried filming news broadcasts or where their kids or parents were on TV and wanted a copy..     You could do it, but image flicker and banding was always the outcome.. The disparate frame rates results in flicker and in this case, gets recorded directly onto the film..   Once burned into the film, the problem is in effect "cast in concrete"...  

Other folks wanted to make a film copy without having to go to the expense of making a contact print  made of the film..  (and having contact prints made, was an expensive endeavor !)    The cheap solution to make a copy, was to simply aim their film camera at a screen where a running projector was projecting the film to be copied...    It worked of sorts. - well; kinda - sorta....  Even a camera that was filming at say 18 fps would not be locked to the projector projecting the film to be copied also running at 18 fps..   The only way to assure a perfect lock was to assure that the projected film was being advanced thru it's  film gate, at the very same instant the movie camera filming would also be advancing the film through it's  film  gate.   When that occurred, the two were said to  be  "locked", or synchronous ..   Keeping the two perfectly locked together in a Master-Slave relationship was deemed to be Gen-Locked...    Gen-Lock is common today in the wonderful world of video, but there was no such a thing in film..  (not for the consumer market anyways)    They could out of sheer randomness be in phase (highly unlikely) and almost always running out of phase, as each ran completely independently of one another...   and on the off-chance they did get in phase, it would most likely be short lived...

Bottom line: shooting film off a TV screen or from another film projector, will result in flicker and image banding which will be recorded as part of the movie...   There is no cure, as the movie camera effectively recorded the flicker...

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Before the film can be transferred, first it must be properly cleaned, lubricated and checked for bad splices and leader added or replaced as warranted..   that is covered on the next page...

Note; the film pages are a work in progress.   Far more to come including slow-motion video of how the claw in the film gate operates and the timing of shutters....