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» Film-Tech Forum   » Operations   » Ground Level   » Dimmable LEDs for Auditorium Dimmers

Author Topic: Dimmable LEDs for Auditorium Dimmers
Justin Hamaker
Film God

Posts: 2114
From: Lakeport, CA USA
Registered: Jan 2004

 - posted 02-09-2016 02:18 AM      Profile for Justin Hamaker   Author's Homepage   Email Justin Hamaker   Send New Private Message       Edit/Delete Post 
I'm curious to know if anyone has found an appropriate dimmable LED bulb to replace the E11 halogen bulbs in certain auditorium dimmers.

I have tried two different versions of the 'corn cob' configuration. One is a bright white (or daylight) color temperature which works properly, but I am not satisfied with the brightness.

Another is a warm white (very comparable to the halogen bulbs) which has the appropriate brightness. Unfortunately it does not dim properly. When I click to dim the bulbs stay full bright until the power reaches the dim setting, then they 'snap' to dim. The dim level is appropriate, but I want the full dimming effect.

I know we could replace the fixtures to use a standard base, but I would prefer to exhaust options for the existing fixtures first. Unfortunately the fixture is too small for an E11 to standard adapter.

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Cameron Andrews
Film Handler

Posts: 29
From: Rexburg, ID 83440
Registered: Apr 2009

 - posted 02-09-2016 02:08 PM      Profile for Cameron Andrews   Email Cameron Andrews   Send New Private Message       Edit/Delete Post 
It is really hard to pin down because of the wide variety of bulbs and dimmers. But one thing that will help is if you leave one halogen or incandescent in the circuit. This stabilizes the current as the dimmer drops the voltage. You can either leave the lamp in the auditorium, or install a fixture in the booth that is on the same circuit. I had this set-up in one auditorium and worked well. As far as lamps go, I have had good luck with Zenaro. I get them from superior lighting. Here is the link to the exact bulb I have been using:

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Paul Mayer
Oh get out of it Melvin, before it pulls you under!

Posts: 3835
From: Albuquerque, NM
Registered: Feb 2000

 - posted 02-09-2016 03:18 PM      Profile for Paul Mayer   Author's Homepage   Email Paul Mayer   Send New Private Message       Edit/Delete Post 
Something like this? shopping

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Dave Macaulay
Film God

Posts: 2136
From: Toronto, Canada
Registered: Apr 2001

 - posted 02-09-2016 08:50 PM      Profile for Dave Macaulay   Email Dave Macaulay   Send New Private Message       Edit/Delete Post 
The dimmer circuit makes a huge difference. A "dimmable" LED lamp that works great with one dimmer may be crap with another.
Keeping one incandescent lamp on the circuit does sometimes help with flickering and weirdness. That lamp will tend to have a short life for reasons I don't understand. A load resistor simulating a lamp won't work as well to dampen LED flickering.
Kelmar has done a lot of work on LEDs and their dimmers. They have a list showing LED lamps that work best/poor/bad with their standard dimmers and a LED output module accessory that helps give smooth dimming almost to off.
For E11 bulbs you will not have as many options compared to "standard" A19 or PAR types.

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Manny Knowles
"What are these things and WHY are they BLUE???"

Posts: 4247
From: Bloomington, IN, USA
Registered: Feb 2002

 - posted 02-10-2016 01:50 AM      Profile for Manny Knowles   Email Manny Knowles   Send New Private Message       Edit/Delete Post 
We use PAR floods, so I can't help with a make/model.


When it was time for us to switch to LED's, there were so many choices (as Dave states). Physical Plant brought over a sample, but the color temperature was wrong, and they didn't dim right. So, rather than experiment with different products, trying to find the closest match, I simply called the manufacturer of the incandescent bulb and asked them to give me the part number of their LED equivalent. I got my answer in about 5 minutes.

I had never considered a compatibility issue with the dimmer system, but, fortunately, the new LED product worked just fine. If I found myself struggling with a compatibility issue, I suppose my next step would be to contact the maker of the dimming system and see if they had perhaps established a list of compatible LED bulbs. If not, then I'd check back with the manufacturer and provide more detail about the system.

So, although I don't have a direct answer, hopefully this thought process might lead you to a bulb that works well.

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Cameron Andrews
Film Handler

Posts: 29
From: Rexburg, ID 83440
Registered: Apr 2009

 - posted 02-10-2016 03:23 PM      Profile for Cameron Andrews   Email Cameron Andrews   Send New Private Message       Edit/Delete Post 
We have had good luck with Kelmar and CFS dimmers (although they are on complete opposite ends of the complexity sprectum). Our Smart dimmers do not dim to zero. With incandescent bulbs you can still see a faint glow, but with LEDs they are still on fairly high at full dim. So we have converted all auditoriums to LED except for the two with Smart dimmers.

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Randy Stankey
Film God

Posts: 6426
From: Erie, Pennsylvania
Registered: Jun 99

 - posted 02-11-2016 03:39 AM      Profile for Randy Stankey   Email Randy Stankey   Send New Private Message       Edit/Delete Post 
Try Cree Lighting.

I've tried a bunch of different products. Cree are the best, in my experience. I've used them at the place where I used to work and I have changed every light in my house to Cree bulbs. I'm 100% satisfied. [Smile]

Also check their dimmer compatibility chart:

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16227
From: Bountiful, Utah
Registered: Jun 99

 - posted 02-17-2016 03:51 PM      Profile for Mark Gulbrandsen   Email Mark Gulbrandsen   Send New Private Message       Edit/Delete Post 
quote: Cameron Andrews
Our Smart dimmers do not dim to zero.
All dimmers have preset levels that can be adjusted internally. I had one site that had Smart dimmers when they were on film. They worked fine and they did have internal adjustments for "Low", "Mid" and "High".

And yes to the Cree LED Lamps. They work good on Kelmar Dimmers. Almost all my customers have already converted over to LED.


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