This is topic Can anything be done with condensation on/in a lens? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Joe Beres (Member # 678) on 07-11-2002, 09:47 AM:
I have a 50mm lens for a Bell and Howell Filmosound 16mm projector. When I put it in and fire up the projector, condensation collects on the outside of the element nearest the gate. This has occurred consistently indoors in an air conditioned environment and outdoors as well. I assume that it is happening due to condensation inside the lens, between the front and back elements. There is nothing on the lens that unscrews, but I am guessing that at some point in its history, the lens was dropped and a seal was broken. Do my assumptions make sense? Is there any simple and inexpensive solution to this problem? Anyone have a good 50mm replacement they don't need (preferrably one that will accept a screw-on zoom adapter)?
Posted by Ken Layton (Member # 133) on 07-11-2002, 10:14 AM:
Is it a genuine B&H lens or is it some other brand/model? What model is the projector you are using? As far as I know, the B&H lenses come apart with standard lens spanner tools you can buy from Edmund Scientific Company.Lenses for 16mm projectors are for sale cheap on ebay all the time.
Posted by Joe Beres (Member # 678) on 07-11-2002, 10:41 AM:
Thanks, Ken. It is an autoload specialist projector, and it is a B&H 2" lens. I could get it apart if I did have the spanner tools, but if I understand correctly, most lenses have a seal of sorts around the elements, and if that is broken, I'm not sure if getting the lens open would help. I will probably be able to find a cheap lens on Ebay (I haven't started looking yet), but if possible, I would like to see if anyone who knows a thing or two about projectors has a lens that might be better than an Ebay Grandma's basement special. Sorry I wasn't more specific from the start.
Posted by John Schulien (Member # 215) on 07-11-2002, 12:28 PM:
Go look on ebay. This is the stock B&H lens. They turn up on ebay all the time and usually sell in the $10-$15 range.
Posted by John Pytlak (Member # 331) on 07-11-2002, 03:26 PM:
If you are sure the condensation is simply excess moisture trapped in the lens (likely due to careless cleaning where cleaning solution got inside?), you may be able to dessicate the lens. Put the lens in a sealed glass jar with a good quantity of dry (activated) silica gel or Molecular Sieves. Within a few days, most of the moisture should be adsorbed and out of the lens.
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