8mm Forum: old & new B&H lens diameters

This is topic old & new B&H lens diameters in forum 16mm Forum at 8mm Forum.

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Posted by Bill Brandenstein (Member # 892) on June 16, 2010, 06:47 PM:

Can any of you good people explain why listings for "newer" Bell & Howell 16mm projector lenses are all supposedly compatible? You'll see 500 series, 1500 series, and 2500 series as all compatible. Okay, fine, but how is that different than other B&H 16mm lenses? Is the barrel size different? Barrel length?

Reason being, I've stumbled across a long-throw lens from Bell & Howell. The problem is that it's smaller than a 2500-series lens by a few mm, plus it's impossible to even focus, even on a distant surface, because the lens has to be positioned too far forward to even go into the projector's barrel. You can actually image the filament with this thing. I'd almost suspect that lens elements are missing but nothing looks amiss.

Posted by John Hermes (Member # 1367) on June 17, 2010, 11:58 PM:

What is the focal length of the lens? Is it a B&H brand name lens? All large barrel B&H lenses I've seen will work with the 500, 1500, and 2500 series. I believe they are 52.5mm diameter in the thread area. Of course, the 100-300 series use a much smaller barrel lens.

Posted by Mitchell Dvoskin (Member # 1183) on June 20, 2010, 06:01 PM:

The 500 series, 1500 series, and 2500 were all manufactured by Bell & Howell. After Eiki bought B&H's audio visual division, subsequent models were re-badged Eiki's and used Eiki sized lenses.

Early B&H projectors (pre 500 series) used much smaller lenses.

Posted by Bill Brandenstein (Member # 892) on June 23, 2010, 06:49 PM:

John, it is a long-throw lens and definitely has B&H stamped on it. However, I'll bet you its Eiki-sized. I don't have exact details handy, which I'll eventually put up here. However, the long-throw lens is only millimeters smaller than the 2500-series holder I'm trying to put it in, and won't focus, so a completely different projector would explain all.

John and Mitchell, thank you. More to come after I have to do some digging.

Posted by Wayne Tuell (Member # 1689) on June 24, 2010, 01:07 AM:

I have an EIKI 75mm lens that sounds like what you describe. I have never been able to make it focus in any projector at any throw. I almost thought it was for a slide projector but it says super-16 on the barrel as well.

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