Experimenting with gearing Flatbed Scanner Optics for better scanning of 16mm film.

[cwatgo1970]

Greetings, I hope this will not start a dreaded fight about scanners. I understand they are not ideally suited for films in the smaller format, and that a dedicated optical film scanner is usually far better suited. However if you read the entire thread you will better understand the limitations at hand and why a flatbed scanner is being used.

Aside from collecting and enjoying range finder cameras I'm also an avid and long devoted collector of antiquarian films. Especially vintage home-movies which have become abandoned. Collecting old films has it's many rewards but it also has it's issues. Many of you are well familiar with how the unsuitable storage of them can lead to a molecular breakdown cycle within the films acetate, which onsets the dreaded decay of what is called "vinegar-syndrome".

Some of the films I encounter are in a advanced stage of acid decay and are unusable with a film projector. Aside from keeping these films well isolated and stored away from my healthy films, if any of the decayed films contain appreciable footage, I will often go through the tedious task of carefully removing the strips of film and scanning them by hand using my Epson 4990 flat bed scanner. A flat bed has been almost priceless for using in this way except for (as most of you guessed it) the limitations it has with small films.

While it does allow for appreciable scans compared to not getting any imagery at all, it would be nice to find a way to improve them. I suspect a flat-beds limitations with smaller formats is largely due with the optics being geared and fixed for capturing the entire scan range on the flat beds surface. If I could add or exchange the scanners optics and manipulate them for better scanning ( even if limited to a smaller area) of the 16mm films, my efforts and time would be far better served. I'm almost willing to risk trying anything on improving capture of what I believe is likely of historical significance for future historians.

I understand that tinkering and experimenting with a scanner in this way is likely risking serious damage or ruin to the scanner. However, the 4990 I have was purchased at a bargain because of ugly paint stains on the housing. I also have a vast assortment of lenses and elements I've removed from old micro-scopes and broken P&S cameras that might allow me to achieve this. I've successfully managed of ways in using them in other cameras, so this makes me all the more confident.

What I don't have however, (which is the reason for the post) is any advanced technical experience or understanding about how a flat bed is geared towards focusing. The lens optics which are small, seem molded and fixed into a plastic housing. I'm not sure if the scanner employs any auto focus ability or if it based on a fixed focus. Also, some of you might know in advice that what I'm seeking to attempt is even possible. I would appreciate any input from any of you and I do thank for your time in reading this (now obviously) long thread. Charles

 

[bensyverson]

The short answer is "don't bother."

At scanyourfilm.com (I'm not affiliated), they'll scan 16mm for 1 or 2 pennies per frame. That's an amazing deal.

Life is short, and your time is valuable. Outsource this!

 

[cwatgo1970]

Greetings bensyverson, I'm scanning films which have advanced stages of acetate decay, which are dimensionally damaged and nauseous with acidic fumes. They are usually 16mm or 8mm (sometimes 9.5mm) movie films on reels which can sometimes be in the length of 400ft. I doubt they would wan't to bother with it. 🙂

 

[t6un]

I know it's not the straight answer to your question but have you considered building a rig based on a digital camera and some macro lens (I would recommend an inverted cine lens on extension tubes/bellows)? That's the way i scan my still negatives: the resolution is good enough while the procedure of scanning even the 36 frames of a still film is a lot faster than doing it with a flatbed scanner.

 

[cwatgo1970]

t6un, It may not be a "straight answer" but definitely a valuable suggestion! Are you able to achieve good results with the finer details in the image this way?

 

[tlitody]

most flatbeds are fixed focus. The lens fov(field of view) covers a portion of the flatbed and the mirror system reflects that to cover sensor. The sensor head has a fixed number of receptors across its width and that combined with the width the lens fov covers determines the scanner native scanning resolution. So to increase the native scanning resolution you would need a lens with a narrower fov but with the same aov coverage so that the sensor is still fully covered. That means a longer focal length lens. That is where the problems start. The longer focal length lens won't focus as close so you have to move it further away from the flatbed surface. And the mirror will be need to be further from the lens and the sensor the correct distance from the mirror. In short the complete postioning of the internals would need to change and you would likely get a shorter useable distance for the scanner to pass over the film thereby increasing the number of scans you would have to do. And thats IF you could get a ll the distances worked out accurately so that the whole thing is in focus.

I would suggest that you try finding/contacting film archivists who may be able to put you in contact with people who have special scanning equipment that could do this.

Otherwise I would recommend you invest in a drum scanner. With a drum scanner you can tape the film to the drum and the quality difference from a flatbed would be great. Much greater than you are likely to achieve with a modified flatbed. And if you wet scan the film (if possible) then a lot of defects will be removed but that might finish off the film completely.

Another option is getting hold of an IQsmart3 flatbed scanner with wetscan accessory which would give significantly better scan quality than a default epson. And the IQsmart3 is an A3 scanner which means you can scan roughly twice as much film is one go than you can with an epson 4990.

Or a Nikon 9000 scanner with glass holders which sandwich the film and give higher quality than an epson flatbed.

i.e. put some money into a better scan device rather than trying to modify what probably won't work in the epson scanner case.

 

[t6un]

Cwatgo, for most of my uses (web and small prints) even a 6MP DSLR has been enough. I doubt you could easily find a screen for your films that outresolves it ... DSLR's are routinely used in making high quality animations too. Hardest part so far has been getting the colors of a color negative right, sometimes I succeed, sometimes not.
The key for quality is the right lens and illumination. If you use the correct cine lens for your film format, you will effectively project the image instead of movie screen on a digital sensor. Unlike movie projectionist you will have the luxury of using the aperture for better sharpness and modifying (diffusing) the light to hide the film defects.
BTW, you could probably automate parts of the process by still using the film transport of a movie projector?