HIGH INTENSITY DISCHARGE Bolex/Eumig sound projector lamp conversion

[Steve Klare]

The joy of it is even if it is the case they are never able to make a drop-in LED replacement in these applications, that's still good for us. The common lamps we use are also used in common scientific and medical gear being made right now. That means if tomorrow morning they obsolete EFP and EFR and others, not only will my screen go dark, so will the screens of dentists and doctors and researchers all over the world. (If I spent $10,000 for a new microscope six months ago, I might take that personally!)

-if it was just us, they would have disappeared years ago, yet they are common and even cheap!

The technology is still advancing, though. (Besides: my fantasy projector aint happenin' anyway!)

I've heard that the rise in electric power consumption in the US has flattened so much that many planned power plant projects have been delayed or even canceled. The reason is the rise of LED lighting. I bought 40W equivalent bulbs the other day and they consume something like 6 watts!

[Nantawat Kittiwarakul]

About a couple of years ago when I went out finding a replacement to my bathroom's 60w CFL bulb, only to find out that those bulb was NLA. All I saw were loads of LED lamp in virtually every shape&form imaginable. I ended up with a dirt cheap 5w lamp, which still works fine today.

Another example - when 35mm cinema release print switched to cyan track about 20 years ago, the replacement LED needed to read the track were relatively pricey - several hundred $$$s for conversion. Fast forward to today I had done more or less the same conversion with standard off-the-shelf high power red LED available online. And it's darn cheap, 3-10$ range.
(OK it's DIY solution vs industrial standard product, but you get the idea.)

[Brian Fretwell]

I wonder just how hot it is at the gate with these lamps. I remember that at the CHC event last August Dave Locke had brought a converted 16mm projector for the garden film show and the dowser he had was a flap of cardboard in front of the lens just to prevent showing a white screen between films, no protection for the film at all!! also someone at big Screen Scene had said a stationary film had not burned without one.

[Lee Mannering]

Very hot Brian.

All components have now arrived and I was set to start but reading up on HID lighting I have serious concerns now having spoken to a professional in the field so placed my project on hold until I find our more.

Has anyone using these lamps looked at the health consequences of using them at home or in a public show? I'm told to forward with great care as if not used with a UV filter they can cause damage to humans including Arc eye. Also they cause fading of dyes so what about film emulsion?
I've placed the conversion on hold at the moment until I receive full technical details here.

The last thing I want is to cause damage to others, myself or even my valuable colour films.

To those who have made home conversions can I ask where if at all did you place a UV filter please?

[Maurice Leakey]

As I said on another thread, the HID 150 conversion of my 16mm Bell & Howell 644 was done eight years ago. I haven't suffered in any way since it was done, nor do I use a filter of any type.


Maurice

[Lee Mannering]

Maurice it's up on wikipedia as well.
HID produce significant uv radiation so require uv filter

Update. Had mail from my video projector manufacturer. Turns out it has a UV and IR coating on the lens element to protect from harmful radiation.
I can only estimate at this stage I may need to look into some sort of UV blocking filter.
I'll be back.

[Brian Fretwell]

I would assume that it is only a problem if you look into the lamp when it is on and a film frame will only get 1/18 to 1/25 of a second. Remember the sun is a big UV producer and some cars have HID headlights now, I saw some being converted to them on Wheeler Dealers.

[Lee Mannering]

From el net research

"HID lights are more energy-efficient than a tungsten-halogen light. Concerns on UV Radiation. However, as these lights emit ginormous amounts of UV radiation, prolonged exposure can result in sunburn as well as arc eyes, especially from HID lights that are found in larger environments"

The enormous word bothers me 😱 I've now ordered in a UV blocker which will be fitted as a precaution particularly as our audience only have one set of eyes.

I've pondered fitting a dowser to the projector and feel its not really necessary on a Eumig as they of course have a inching knob on the back so I can turn this to use the metal shutter blade to protect the film frame when stationary. Another win from Eumig.

Reading up on a suitable cable to connect the HID lamp to the ballast I see its recommended to match it as if not we have possibility of ignition problems but that is an easy can do.
A suitable high revolution cooling fan is on the way now so in the next few weeks I should have this complete.

Cosmetically I'm tempted to recreate the look of the Eumig Xenon 850 with some aluminium sheeting. This will assist with light leakage and the air draw to the lamphouse can go up to the fan as it did in the original 850 prototype.

Making cautious progress and awaiting more parts for the EUMIG 860 HID SUPERLUX 😎

[Brian Fretwell]

I have also read that the HID class of lamps also includes Short arc Xenon lamps so the U/V problem shouldn't be greater than with GS 1200 Xenon projectors.

[Lee Mannering]

Update: All parts ordered have now arrived, additional cooling, UV block as a precaution etc so further work can proceed at a steady pace. I'm going to replace the amplifier capacitors in the machine I'm going to use as well.
The additional silent cooling fan will go on the front lamphouse with a fabricated cover semi open at the bottom for the air stream to be drawn thru as per the original Xenon 850.

Once its all assembled working 'we ope' and PAT tested I hope to take it to a privately operated Cinema and project my Star Wars trailers at a distance from the screen, now that will be a reel test.

More thrilling moments with the new DUAL GAUGE 860 HID Kinomatograph will follow.

[John Burgess]

Hi lee, converted one of my Kodak 8 sound projectors to HID around 4years ago. The 12v 100watt diochroic that I had fitted previously is around 8amps, so I figured the HID at only 1.5amps would receive adaquate cooling with the original fan. So far I have run about 30 hrs of film through and have not had any problems at all. Black and white prints are a joy to behold now, most of my features are B/W , colour also looks superb . Hope this has been helpful and good luck with the Eumig.
regards John

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[Lee Mannering]

Hi John aka Mr Standard 8 :-) Hope you are keeping well. It's all going to plan at the moment and busy fabricating an extension for the lamp house to accommodate another fan for up draft.
The original Eumig Xenon was Super 8 only but my 860 will do Std and Super 8 when its done.

[John Burgess]

Hi again , looking forward to seeing the finished job, keep us posted on progress. Yes, still collecting St 8 films ,just love the chase. Hoe u and Val are keeping safe.
kind regards John

[Brian Fretwell]

Lee, I've joined you in ordering parts and hope to try this in a 900 series Eumig but intend to make it movable so I can try it in a B&H 16mm 2692 as well. Now all I need is some time to plan the exact details for spacing etc and to do the work!!!

[Brian Fretwell]

The lamp and ballast, I ordered separately off different companies both arrived this morning. Time for planning.