8mm Forum: Projector Lamp Reflector Update!!

This is topic Projector Lamp Reflector Update!! in forum 8mm Forum at 8mm Forum.

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Posted by Roger Shunk (Member # 2836) on October 03, 2013, 11:25 AM:

Greetings fellow film enthusiasts

On the ELC bulbs does it make any difference if the reflector is smooth or faceted? I was just wondering if one is better than the other and why they offer both types?
Thanks,
Roger

Posted by Jon Addams (Member # 816) on October 03, 2013, 01:19 PM:

Hello Roger,

There are Pros and Cons arguments for each design, and to the best of my knowledge, there are no explanations why a manufacturer chooses one design over the other. Until we get a logical answer we can use a Lux meter to see which one projects the brighter light.
[Wink]

Jon

Posted by Roger Shunk (Member # 2836) on October 03, 2013, 01:38 PM:

Greetings Jon and thank you for your reply! I went online to order a couple of bulbs and they offered the smooth reflector or the faceted so I guess I will order one of each then and do a comparison.

Have a magical day!
Roger [Cool]

Posted by Maurice Leakey (Member # 916) on October 03, 2013, 03:02 PM:

We await your report, Roger, which will be interesting. Why should two lamps be manufactured which only appear to differ by their reflector surfaces?

Posted by Jon Byler (Member # 3933) on October 03, 2013, 07:44 PM:

Jon Addams,

Can you elaborate a bit on the pros and cons of the two designs?

Posted by Jon Addams (Member # 816) on October 04, 2013, 09:41 AM:

Hello Jon,

The question posed by Roger intrigued me as I have heard it before but never gave it much thought. After your question I did a bit of research and I believe this post offers an excellent explanation of the topic at hand.

Jon

Posted by Maurice Leakey (Member # 916) on October 04, 2013, 09:55 AM:

Having clicked on the link provided by Jon Addams, I read the following:-

"Faceted reflectors, if focused to a tight light beam scatter some of the light, so you will never achieve the same tight light beam you could get with a smooth reflector".

Can a "tight light beam" refer to that used in a Super 8 (or 16mm) projector? If so, the smooth reflector seems to win.

Posted by Roger Shunk (Member # 2836) on October 04, 2013, 11:45 AM:

Hey Jon,
Thank you for that post it made for some very interesting reading and helped solved the reflector lamp mystery!
Good job! [Smile]

Roger

Posted by Jon Addams (Member # 816) on October 04, 2013, 06:46 PM:

Thank you Roger, interesting reading indeed!

Jon

Posted by Roger Shunk (Member # 2836) on October 05, 2013, 02:49 PM:

Here is the latest update and this is what I read about the lamp reflectors from a site that sells both lamps.

Osram & Donar smooth reflectors are ideal for DJ Lighting.

GE & Philips w/faceted reflectors are ideal for movie projection.

I just got both today in the mail and I'm going to test them both out and report my findings! We will see if there is any difference between the two?
RS

Posted by Robert Crewdson (Member # 3790) on October 05, 2013, 03:25 PM:

You would have thought it was the other way around; smooth surface for projectors.

Posted by Jon Byler (Member # 3933) on October 05, 2013, 11:04 PM:

Roger,

Do you have a light meter that can measure the quantitative differences in brightness between these lamps? I suppose the only real way to know would be if your projector had a way to make sure the lamp is centered properly, or maybe to try a bunch of one and a bunch of the other to make up for possible differences in filament location.

Either way, it will be interesting to see if you find any difference between the two types.

Posted by Maurice Leakey (Member # 916) on October 06, 2013, 02:15 AM:

I keep spare lamps for my many projectors and all of the reflector lamps have a smooth surface. The faceted lamps must have been newly introduced and are probably for disco use.

But the proof is in the pudding, so we must wait for Roger's report with his new lamps.

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