Fresnel retrofit LED
- Thread starterJohnD
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porkchop
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dthomas32308
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Been doing prop light LED retrofits for years - like ten or fifteen years now, even back to the days of installing Mac 101's into them, even converted 10K to 2K incandescent given some engineering. Almost a constant thing for me in adapting studio Fresnels to something else from Color Blast to Pups. I even mastered taking a perfectly good CYX lamp base and diamond grinding it down some in size so as to mount a E-26 lamp socket adaption to it for LED A-19 lamp. (ETC and Altman have done the conversion retrofits, but only up to 575w in power).
Interested! though. At times tough this might save time assuming one would still have to remove the electrics and convert the fixture I would assume to a smaller power supply.
Interested! though. At times tough this might save time assuming one would still have to remove the electrics and convert the fixture I would assume to a smaller power supply.
A BTR/BTN Fresnel LED replacement upgrade doesn't seem that difficult. You've got tons of room inside the fixture to hold the replacement device. Fresnels are so inefficient due to the silly small reflector that the LED replacement could be significantly lower wattage and produce more light. Plus the physics involved are not nearly as complicated as the point source required for an ellipsoidal LED. Make a 3200k LED white with high CRI that you can pop the reflector off and screw into the medium prefocus base and you are good. The only real trick would be making it smoothly dimmable.
(Get to work @DELO72 !
)
(Get to work @DELO72 !
)Alot more engineering than that involved! Probably cost prohivitive for a market that normally doesn't have a lot of money for upgrades that cannot afford new gear. I remember the old 1960's catalogues in retrofit kits so as to make a incandescent Fresnels into a halogen Fresnels - before the BTN came out. Can LED be done... yes, somewhat easily but it's a question of having a 500w luminous output sufficient node to start with. Yes such security or wash lights are on the market now one could start with that might have the power. So you buy the fixture and remove the components, cut the reflector down to fit and use its say 1" square node. Or separate the node from reflector in only using it.
Believe the norm for LED's is 120 degree beam spread, a lot of light now is not focused in the Fresnel lens as per a point source especially the closer you focus to it in giving a even beam at all focus points. That's the start - source of light efficiently matching up with the lens. Next if going P-28s lamp socket installation of assembly for easy retrofit, you have to engineer squaring what you do to the lens and making it strong. Than given a normal voltage of 24 or 12VDC for LED have to include the wiring/electronics package somewhere remote or inside the light. heat sinks?
Encourage the invention of something one can afford and or perhaps someone will do it one day - the upgrade for Fresnels, but it's complex - such an idea. Recently took a street light and made it RGB LED for a tour. Basically took a fixture, mounted a 1/4" plate of aluminum and did like 28x strips of high output RGB LED tape to the plate. Was it as bright as a normal street light - probably not. Remotely located was power supply and DMX encoder box almost as large as the light - one PSU each light. Very expensive to fabricate and in parts.
Believe the norm for LED's is 120 degree beam spread, a lot of light now is not focused in the Fresnel lens as per a point source especially the closer you focus to it in giving a even beam at all focus points. That's the start - source of light efficiently matching up with the lens. Next if going P-28s lamp socket installation of assembly for easy retrofit, you have to engineer squaring what you do to the lens and making it strong. Than given a normal voltage of 24 or 12VDC for LED have to include the wiring/electronics package somewhere remote or inside the light. heat sinks?
Encourage the invention of something one can afford and or perhaps someone will do it one day - the upgrade for Fresnels, but it's complex - such an idea. Recently took a street light and made it RGB LED for a tour. Basically took a fixture, mounted a 1/4" plate of aluminum and did like 28x strips of high output RGB LED tape to the plate. Was it as bright as a normal street light - probably not. Remotely located was power supply and DMX encoder box almost as large as the light - one PSU each light. Very expensive to fabricate and in parts.
Too much in post on my part perhaps given the NAB far above posting - off topic on my part given its been done. I remember my many days of trying to reproduce the engineering of a c.1936 Pratt #73 missing all gizzards. While different type of light, still the same challenges. Have not tried the above but curious.
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