This is topic Lens Port Blower Thingy?? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Barry Floyd (Member # 385) on 11-21-2000, 02:46 PM:
Does anybody still make the lens port shrouds with the "blowers" on them that were used extensivley @ drive-in theatres?
I think the blowers were intended to keep insects out of the light beam @ the port.I've got two I ripped off the walls of the booth I bought back in May but there in pretty bad shape.
Posted by Matthew Bailey (Member # 601) on 11-21-2000, 02:51 PM:
Probably not. I think the blowers were
used to keep the lenses cool if high
wattage lamps were used.
Posted by Ken Layton (Member # 133) on 11-21-2000, 03:29 PM:
Barry:Please post a picture of them or email to me.
If the motor is shot, I might be able to find one.
Posted by Bruce McGee (Member # 131) on 11-21-2000, 05:49 PM:
Doesent Grainger still sell a compact blower to go over, say, a drive-thru window to hold the heat/cool inside the building? Isn't this an air curtain? I bet this would work!Barry, I'll be coming to Nashville hopefully before Christmas. I'd like to meet you face to face! 
Bruce
Posted by Tim Reed (Member # 137) on 11-21-2000, 10:11 PM:
The blowers were intended to keep dust out, so you could run with no glass in the port. SPECO used to list them in their catalog, but I doubt they still have them. Ya never know, though.It wouldn't be too hard to have an HVAC man or a mechanical shop fashion one for you.
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Better Projection Pays!
Posted by John Eickhof (Member # 323) on 11-21-2000, 10:13 PM:
They were made by Best Products, They were designed to keep bugs out of the booth and from the light beam near the projector.
They were made 12" x 12" and had a small blower attached. I have two used ones in decent shape. Email me for deatils! John
Posted by David Kilderry (Member # 142) on 11-22-2000, 04:26 AM:
Barry,Drive-ins in some cases used blowers instead of port glasses to assist in delivering every last bit of light to the screen possible. When you consider most drive-ins could read less than 4 footlamberts, the loss made by a often dusty port was measurable.
The blower was not to cool anything or keep heat in or out but soley to stop moths and insects from landing on the projection lens and keeping rain off the lens.
I never understood why more drive-ins did not have blowers as you could clearly see the light loss when the port glass was placed in front of the lens (only our film projection ports had blowers, slide projection ports and observation ports were still glass.
David
Posted by Barry Floyd (Member # 385) on 11-22-2000, 07:34 AM:
You guys are great.
With a little work, I could probably get these two I've got back in working order. I've looked through the "Grainger" catalog and they have every shape and size blower I could ever want. I just didn't know if you could still by them.I've seen many drive-ins with NO port glass - only a hole in the concrete block wall of the booth. The new drive-in in Argo, Alabama uses a fixed port window with no blower at all.
Posted by Tim Reed (Member # 137) on 11-24-2000, 09:53 AM:
quote:
They were designed to keep bugs out of the booth
According to period literature (maybe it was in the DITMCO catlog, too), the idea was to keep dust off the front of the lenses (sorry, I can't site specific references presently, as all my materials are in storage).
Seems to me, if they had been designed to keep bugs out, there should've been blowers on ALL the ports and doors... not just the projection ports. Whereas dust through these other inlets wouldn't have mattered as much, as far as the lens was concerned (although we all know it didn't make much difference anyway).
I'd never heard the bug thing before, but I guess it would perform the same function. 
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Better Projection Pays!
Posted by Rory Burke (Member # 512) on 11-28-2000, 12:21 PM:
Well they were probably designed for dust but if you think about it in states like Florida or Texas where there ARE alot of bugs these blowers assumed a secondary function. They have "Florida Rooms" for a reason. <Backyard patios boxed in within netting as bug shields>Rory