Alternate light system

I posted my scanner design a while back but after many issues with camera’s, film gate etc I called time on it and went over to the dark side…

Several years ago I bought a film projector which has been lying idle. This has now been gutted and modified to use with my dslr + macro lens and all is going well. My films have only been viewed a few times so sprocket holes are very good and suitable for a claw advance.

The light source evolved quite accidentally when I saw a dental uv curing tip on eBay - 12mm od 10mm fibre and 12mm connector. After reading about various led light sources on this forum I found a reel of CRI (RA 97+) on amazon. I cut down a bundle of 0.7mm fibre guides which feed the top of the curing tip. Unfortunately the tips are only available in one form so I used some 10mm fibre guide (eBay) to make the bend. This is a bit crude and not too happy with the bend radius but it works. I have a second tip on order and will be able to create a 90 bend and use the finished end at the film gate which will be much neater.

The led’s require 12V and are powered from a step down converter from my stepper motor 24v supply. The converter has a lcd display and allows push button voltage setting in about 50mV steps. This is great for setting exposure and could easily be automated. I used 6x leds as I was not sure how much light would be needed. As all the light ends up in the same place it may be possible to uses different colours and expose for R,G & B separately. The led strip is exposed to the air and helps with cooling although the power consumption is only 150mA - ish.

The scanner is a work in progress but very happy with the quality and stability so far. I will post more info when completed.

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That’s cool I always wonder about optic fibre for backlight -love it Patrick

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Thanks, I did try to add a couple of pieces of diffusion material by the gate but realised the curing tip already does this and you get even light coverage. I did buy a 1m length of 15mm fibre but difficult to route on this frame. Probably suitable for anyone using a straight path.

The 10mm & 15mm fibres are listed on eBay as “side glow”. I am assuming that not only will light leak through the wall but it may be possible to use it in reverse and place the leds on the outside and feed down the fibre. Great for RGB applications. On my list of things to try.

Not only cool, but “cool”! Thinking outside the box.

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