This is topic Bolex M8 / 18-5 standard 8mm / lens? in forum 8mm Forum at 8mm Forum.

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Posted by Thomas Dafnides (Member # 1851) on October 23, 2010, 10:22 AM:
Were the lenses on these projectors interchangeable?
Posted by Barry Fritz (Member # 1865) on October 23, 2010, 02:24 PM:
Posted by Joe McAllister (Member # 825) on November 03, 2010, 04:54 AM:
I think you may be wrong there Thomas. I use an old bolex 12.5 to something zoom rescued from an 18 5 on my M8 which has been upgraded to a 24v 250w lamp to show standard 8 alongside 16mm on a 6ft screen. The std lens from the m8 is now in the 18-5.
Posted by Bryan Chernick (Member # 1998) on November 03, 2010, 03:37 PM:
Reading some older posts it sounds like the M8 would have to be a model made after December 1959 with serial number 467221 or later for the lens to be interchangeable with the 18-5. The following is the thread that I got this from:;f=1;t=003397#000000

I also learned reading some older threads that the 18-5, 18-5 auto and 18-5 super all have interchangeable lenses. The 18-5L lens is not compatible with any of them.
Posted by Rob Watson (Member # 382) on November 09, 2010, 06:25 AM:
The spiral grove in 18-5 and later M8 lenses is narrower than the grove in early M8 lenses. That means an 18-5 or late M8 lens will not fit an early M8. However an early M8 lens will fit a later M8 or 18-5 albeit with a bit of forward and backward play.

I'm not sure what an 18-5L is. How does it differ from the other variants?
Posted by Barry Fritz (Member # 1865) on November 09, 2010, 07:38 AM:
The 18-5L is a Super 8, Autoload machine. It originally came with an incandescent lamp that was different from the previous 18-5 machines. Later models came with a halogen lamp. If you are considering buying this model, make sure you get the later one with the halogen lamp, as the early model 18-5L incandescent lamp is now obsolete and will cost you at least $50.00 if you are lucky enough to locate one. The lamp for the other early 18-5 machines looks the same (it's referred to as the "Spaceman" lamp), but is readily available for about 15.00. If you have the incandescent version of the 18-5L, Urbanski has a kit that they can install to convert it to the halogen lamp for 75.00. Lenses from the 18-5L will not fit the other models.

[ November 09, 2010, 09:27 AM: Message edited by: Barry Fritz ]
Posted by Bryan Chernick (Member # 1998) on December 05, 2010, 02:20 PM:
Now I'm confused. The lens in my Bolex 18-5L had some mold issues so I started looking for a new lens on ebay. I found another 18-5L for cheap so I purchased it for the lens and other parts. When I got it I noticed that the lens is smaller in diameter (see photo below). It's the same size as my 18-5 regular 8 projector. Upon closer inspection the auto load mechanism is different. It looks more like an 18-5 Super. The serial number for the one on the left is 4400467. According to the Bolex Collector web site it is an 18-5L made in 1967, the first year of this model. The one on the right is serial number 4423796, made in 1970 (it uses the halogen lamp).

My plan is to move the smaller lens holder over to the 1970 projector. everything looks to be the same size except for the diameter of the cylinder that the lens mounts in. This way I can interchange the lenses between my 18-5 and 18-5L.

I wonder if the 1967 projector was repaired at some point using older parts from an 18-5 super. Or did Bolex change the auto feed mechanism and lens size early in production of this model.

If anyone can think of a reason not to switch the lens mounts let me know before I mess something up. It looks very simple, there are just two screws holding the hinge on.


Posted by Barry Fritz (Member # 1865) on December 07, 2010, 08:01 AM:
I checked my 18-5L projectors and the early incandescent bulb projector has the same auto-load mechanism as the latter halogen bulb model. The mechanism you have on your early model is the same as what I have on my 18-5 Auto and 18-5 Super. It requires that you press down on the top loop-former to auto-load. The latter mechanism just requires that you insert the film. Perhaps they just had some of the earlier mechanisms still laying around at the factory, and threw it on your machine when it was produced. My instruction manuals and an advertising brochure show the latter mechansim also.

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