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Kickstarter candidate: adapt LED tech for brighter projector bulbs....

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  • Kickstarter candidate: adapt LED tech for brighter projector bulbs....

    I think it's something that is probably doable but nobody's done it. There are one or two youtube clips that show some DIY attempts but it's almost impossible to film the screen with an iPhone. So it's virtually impossible to make a qualitative judgement.

    Theoretically, if LED delivers something like 4x the Lumens at the same wattage, why not? I know the beam must be focusesd through the gate, but LEDs on automobiles have lenses that deliver the beam of light right where it needs to go.

    First car I owned with LED it was shocking to see how focussed the beam was. Like a straight horizontal line where the LED projector lens inside the front headlamp assembly cuts off the beam.

    So we know LED can be directed or focussed. Is it just a matter of precise miniaturization of the elements required for small gauge film gates?

    My thinking is that this may require some sort of sophisticated array of LEDS to get the desired result, and that may be why drop-in replacements for projectors aren't available like drop-in replacements for household incandescent bulbs.

    Has anyone here tried it, or known of any attempts to make this happen?

  • #2
    Hi Todd,
    I did try this a few years back with my 16mm projector.
    With a projector lamp the light source is emitted from the filament, or in the case of a xenon from the arc, which in both cases is omnidirectional and can be focused by a reflector mirror.
    With leds the light is emitted in one direction and can not be used with a mirror, in order to produce a led lamp that can produce the same amount of lumens as a conventional halogen bulb multiple led diodes are needed in a cob, which can get quite large in size.
    The one that I experimented with was a 300w led. this need a dc driver to power it, also a 5v transformer to power the cooling fan on the heatsink, as these run very hot. The driver was half the size of an average super 8 projector.
    This makes the perfect floodlight ( absolutely blinding ) it is necessary now to focus this down to a point to hit the back of the film gate. The only way of doing so is with a condenser lens. After doing this I found the beam of light passing through the projection lens was very bright, the problem was then you looked at the screen.
    All you can see is the array of led lights in a grid. This is because the light is not being generated from one spot.
    Also in order to focus the light on the back of the gate, the led needed to be position about 12" from the gate.
    I spent quite a lot of money to see for myself if this was possible to do, all I ended up with was a very bright ,very expensive floodlight for my garage.
    I guess until the technology comes around where it is possible to produce a single chip led that can deliver the lumens necessary to achive this, I will stick with an HTI lamp.

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    • #3
      There are already some LED lamp replacements, e.g.:
      https://web.archive.org/web/20220524...aspx?sid=34861

      https://van-eck.net/product/led-lamp...ne-5w-dimbaar/

      https://van-eck.net/product/projecto..._lm_-_dimbaar/

      But so far, they’re all limited to an equivalent of 50W halogen (maximum).

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