Super 8mm Film-to-Digital Transfer, the hard (crazy?) way

September 4, 2002

If you own 8mm or Super 8 mm films with anything important on them then you should make sure you have them properly stored.  Also consider having them copied to another format while you still can, because they are slowly fading away and deteriorating --they might even be too far gone to save already.   Recently I scanned some old color 35mm slides (about 30 years old) and discovered to my horror that a fungus had started eating away at the emulsion of the pictures, leaving bright purple cracks all across the images!

Don't let this sort of thing happen to your irreplaceable images!  Relatively inexpensive 35mm film scanners exist and you can do much to repair the damage using ordinary home computers and programs such as Adobe's PhotoShop or Photo Deluxe.  

Preservation of 35mm film images by scanning is fairly straightforward, but what about your old 8mm or Super 8mm movies?

Why not hire someone?

There are many commercial transfer services available that can transfer various types of movie film to videotape as well as DVD.  Your corner drugstore could probably send your film off somewhere to do the job.  However, the quality of what you get back will vary among providers, the service tends to be expensive, and you have to trust an unknown party to not lose or damage your film.

Perhaps naively, I decided to try doing the job myself to avoid the problems mentioned above.  Thus, I began down a long road of many other problems to solve.

Pandora's Box of Problems

I tried several variations on the simplest method which involves pointing a video camera at movies projected from a movie projector.  This works moderately well when the source film is 18 frames per second (fps), surprisingly well with 16 fps films, but is barely tolerable with 24 fps films.   This is true regardless of whether you project onto a smooth white surface, through rear-screen projection material, or through a large convex lens (to create what is called an aerial image).

The main problem is flicker.  Video runs at almost 30 fps, so if you just point a video camera that is taking pictures at 30 fps toward a projected image of 24 fps, some of the video frames will be taken in between the still movie frames when the screen is black, some will get part black and partially exposed to the next frame, while others may get a mix of two separate movie frames (depending on the speed of the film and actual speed of the projector).

Other problems relate to the quality of the optics of the projector and camera.  Proper exposure and white balance must be dealt with also.  If you use the aerial image method, the center-to-edge thickness of the aerial image lens and its glass color can come into play, as does even light exposure across the image to avoid a center "hot spot".

Furthermore any film (even Super 8mm film) can have a wider exposure range (from dark to light) than video.  This means you may have some scenes that when exposed correctly for dark areas of the image end up with bright areas completely washed out to white or even "bloom" out over surrounding areas.  These "hot spots" look very bad.  The alternative, allowing dark areas to completely disappear into blackness is also bad.  This shallow contrast range of video (exposure latitude) is why so much TV programming uses fairly flat studio lighting.

Format Obsolescence

The problems mentioned above relate to transferring film to video.  Is video really a good format to store your keepsakes?  Consumer audio has moved from Edison cylinders, to 78 rpm ceramic platters, to 33 and 45 rpm vinyl platters, to reel-to-reel tape, to 8-track cartridges, cassette tapes, Dolby encoding, CD's, Super CD's and lately MP3's.  For consumers, moving pictures have gone from 16mm to 8mm and Super-8mm, then Beta, VHS, Super VHS, Laser disk, DVD, and lately, HDTV.  In the future, we might be using holographic crystals or who knows what!

No consumer format is guaranteed to be permanent.  Even a current DVD may eventually break down and fall apart, be stepped on and broken, melted, burned, or be eaten by some household mold or fungus.  And if the storage media itself survives, the equipment needed to play it back with may be broken or not exist anymore when you do want to hear or see it again.

The only reasonable route to longevity is to preserve the data itself; audio and images in digital form, with multiple copies stored in multiple places (to protect against disasters).

So, to preserve my own old Super-8 films, my first hurdle was to decide how to make the highest quality digital copy of the images I can within my budget and abilities.

Simple in Concept:  photograph each frame, one at a time

All movies are just a lot of still photographs.  Why not photograph each frame with a good digital camera, download these pictures into a computer where they can be processed and reassemble back into a movie for output to tape or DVD?

At first a high-resolution film scanner similar to those used to scan 35mm slides seemed like the best approach.  Unfortunately they don't seem to exist, at least not at an affordable price.  The few I could find which do exist (at this time) are modified versions used to do digital transfers of 35mm and 16mm movies.  And very expensive.

I explored other possible mechanisms that might advance Super-8 film a frame at a time in front of a light where they could be re-photographed.  Using a movie camera itself could work, but they don't provide any mechanism to handle the supply and take-up of larger reels of movie film.

I finally settled on using an old movie projector and modifying it as needed.  These are getting hard to find, so I resorted to mail order.  This meant I could not disassemble and inspect the machine internally before buying, so the process was hit-and-miss to locate one I could use.  My first two purchases over Ebay turned out to be unsuitable for the modifications I needed to make.  I was able to "make do" with the the third one, but only with a great deal of work to modify it. 

As this project progressed I searched many discussion forums and information resources on the world wide web to see if I could find anyone with any similar experience willing to share some advice about this type of a project .  Bits and pieces came from various helpful people about different parts of the project, and I finally found one other person working on the same sort of approach as myself, Jean Beaumier of Montreal, Canada, who has been very supportive and helpful as we shared ideas about how to solve various problems in common.

Equipment Used

So, after a great deal of research on affordable digital cameras, trial and error with various purchases, and studying and trying several optical methods to photograph the tiny Super 8 movie frame, this is the system I settled upon:

Projection:  an extensively modified Bell & Howell Lumina MX60 Dual 8 projector.  The original motor was disconnected and it is driven instead by a home electric kitchen mixer (picked up at a Goodwill store) geared down and connected to a motor speed control unit.  This allows adjusting the projector speed to a very slow frame-per-second rate needed to match the quite slow remote capture speed of a digital camera under computer control.  At this time, no affordable digitial cameras offer Firewire or USB-2 connections.
More recently however, I have discovered inexpensive sources on the web for stepper motor controls, which would probably allow better speed control and be more reliable in the long run.  Another alternative might be found in the motors and gears selection from Edmund Scientific.  Oh well, "20/20 hindsight", if only I'd known then what I know now, etc.
Camera:  a Nikon Coolpix 990 digital camera, purchased on Ebay.  This camera has ideal optics for macro photography.
Unfortunately, it appears that this is the last model in the Coolpix line that Nikon made which allows computer remote control of the camera plus picture download over a USB port.  With newer Coolpix models the USB connection can only be used to download pictures already taken --the essential remote control is not possible except over the serial port.  However, this means picture downloads then have to go through the same serial port which is simply too slow.  Even the USB port (version 1) of this Coolpix 990 camera is really quite slow --it takes almost 20 seconds to download a hi resolution jpeg image.
If this camera were to burn out, I would have to look again seriously at the Canon and Olympus line, which don't have this remote control limitation.   They present other problems however, mainly with the optics, and the camera bodies are larger too.
Extra optics:  a Raynox MSN-500 "Super Macro Scan Close-Up Conversion Lens, 2.5x, for Nikon Coolpix Cameras".  Used and recommended to me by Jean Beaumier, it seems to do the job pretty well.  It doesn't give a 100% full-frame close-up of the Super-8 frame, but much larger than the naked Coolpix macro.  The final Super-8 frame ends up roughly 1340x960 pixels in size --more than adequate for a transfer to video tape or DVD resolution, and probably higher than what is in the film frame itself.

Photos of my Custom Contraption

Here's my own somewhat ugly but functional homemade hardware:
(Click any photo for a larger view)

Front view:  the modified projector is bolted to a piece of plywood.  The round bulge on the top is an extra cooling fan which blows air into the light bulb chamber because the original motor and fan are disabled.

A variable motor speed control unit is mounted with a power socket to the left.

Backside view:  the back of the projector is left open.  The original motor (left side) is still in place, but disconnected.  A large gear (right side) was attached to the motor shaft.  An cheap electric mixer from Goodwill drives the projector instead.  The bottom half of the mixer was removed and it is bolted to the plywood so that one of its drive gears meshes with the large white nylon gear.  

Side view with camera:  I bought this projector via eBay (for roughly $60) because it uses a gentler and safer sprocket-free film drive --and because it had a variable speed selector for 18, 9, 6 and 3 frames per second.  I knew I would need to run the projector at very slow speeds.

After examining the internal mechanisms of the projector I saw that the projector achieves slow motion by using a cam system that holds the pull claw up away from the film sprockets for some of the claw's up & down cycles.  This lets the pull-down claw continue to move up/down at 18 fps, while the skipping (step frame) action gives a true slow motion  yet the drive motor runs at a single full speed.

In hindsight, this was not a great choice of projector to modify.  I ran into many problems and it took a great deal of time and extra modification to make it work.  Even now, I am not 100% confident it will hold up and perform as it should. 

Here's the Coolpix camera mounted on my improvised "tripod" mount (actually some metal flanges from a hardware store).   

The film trimmer from the projector serves as a strong spring to hold down the bottom of my makeshift "tripod" against the plywood (and some playing cards used for shims) and allows very rough positioning of the camera.

Screws allow crude adjustment of the angle of a large washer against the camera's foot.  

With the side panel removed, you can see that the original projection bulb has been replaced with a simple vanity light bulb available just about anywhere.  I started with a 40 watt bulb, but found that a 25 watt bulb works just as well and is cooler.  The bulb's electric socket is toward the top --the bulb just rests on the old original socket.

You can see how virtually all of the original projection gate and lens had to be cut away to allow the Coolpix camera and macro lens to fit inside.  So much had to be removed that there is almost nothing left to hold the pressure plate in position!  I would definitely choose a different projector if starting over.

The projector's shutter blades were also removed (actually, they had to be cut away --a Dremel moto-tool cutting/grinding wheel did the job). 

From this angle you can see how the macro lens is held in place.  Just two simple screws (with plastic tips) run through the hard plastic body of the projector.  The lens rests on a metal spacing shim set to the right height, and these screws lock it down.  It holds surprisingly well.

Mounting the camera and lining it all up properly does take awhile though.  

The camera focus is set to manual mode, at infinity.  An external 15 inch TV screen is used in place of the camera's viewfinder to assist setting the focus while nudging the camera into place before locking it down.

Slow camera shutter speeds are used to force a very small aperture setting (between f8 and f16 or so) which helps give a finer focus by improving the extremely shallow depth of field a little.  The camera's auto-sharpening feature can also be used, but the Coolpix's contrast setting needs to be set to LOW to help avoid blown out highlights and exaggerated shadows.

A switch of some sort was needed to trigger the camera to snap a picture of the projection gate each time a new movie frame moves into position.

A simple micro-switch is mounted just above the light bulb.  It has a spring roller which "rides" the back of the pull claw, which normally would move up & down at a constant 18 fps but be held away from the film for some of these up/down cycles to achieve slow motion.  Of course, I modified the project to run much much slower than 18 fps (actually, about 1 frame per 15 seconds!) but even that isn't always slow enough for the camera to transfer picture data to the computer.  The switch on the pull claw allows using the projector's slower cam-geared modes too:  when the claw drops into the film sprockets to advance the film the micro-switch's contacts close so as to trigger the camera after actual film frame advances only.  This micro-switch is wired in series with a magnetic reed switch which is triggered by a magnet mounted on what remains of the shutter.  This just limits the switch trigger to a narrow time when the film frame is certain to be in place, and not in the process of being pulled down by the pull claw!

The switch is wired to a computer keyboard which I modified by tracing the wires from the most useless key on the keyboard; the "Scroll Lock" button.  Software on the computer watches to see when this button is "pressed" by the projector, and then triggers the Coolpix camera to snap the picture and then it downloads it to the computer's hard disk.  This cycle repeats for each frame in the film.

This is the new substituted light source for the projector.  A simple 25 or 40 watt vanity light bulb.  It seems to give a uniform enough light for such a tiny film frame, and the Coolpix camera has no trouble matching the white balance to it.  Of course, fluctuations in the house current voltage might cause some variance in the brightness from frame to frame, so adding a voltage regulator might be needed.  Bulbs like this can also dim with age.  Results will tell later if more attention is needed here.  

(web page still in progress)