Is there danger of damage to lens cememt by leaving a camera in a closed, locked car in the hot summer?
Damage to lens cement in hot car
Is there danger of damage to lens cememt by leaving a camera in a closed, locked car in the hot summer?
Wilhelm (Sarasota)
Pardon my obviousness but why leave it in a car, on a hot summer day, in the first place?
Lasse, when one travels leaving luggage and gear in the car is sometimes unavoidable. And here in the north intemperate zone summer temperatures can be quite high. Florida, where Bill lives, is sub-tropical, i.e., even hotter.
Bill, modern cements aren't affected by heat. Canada balsam softens when warm. I've cooked some old lenses in my car's trunk in Arizona (ambient 100 degrees F) with no ill effects, though.
I attempted to seperate two lens elements in a fairly old barrel lens a couple of months ago, using my oven as the heat source. What I should have done is put the lens in at the beginning and let it warm up with the oven. What I did was to put the lens in after the oven was at 300-deg F. Never seperated, and one of the elements "crizzled" which so far I've not found a good repair. This link discussed this problem at length http://www.apug.org/forums/forum147/...s-problem.html. So, back to your question, if it was a really old lens and the inside of your car got up to ??? deg, I suppose something could happen that was not good. Great answer, eh? Ok, I have no idea. Never mind ;-)
The only trouble with doin' nothing is you can't tell when you get caught up
While not exactly on topic, here's a bit from Steve Grimes website on re-cementing lenses:
http://www.skgrimes.com/popsci/index.htm
An interesting read, with pictures!
Yes, there is a danger.
The biggest danger is to older Angulons, where only the outside element of each cell is attached to the barrel. The two inner elements are free to "slip" when the cement (canada balsam) softens, causing misalignment.
In fact this may be part of the reson of the poor reputation of these lenses in USA; all of mine were bought from Germany and are exellent. But i make sure I always store them flat, never on edge.
Most other lenses have all cemented elements supported by the barrel, but there is still a very real risk of slippage - especially with older lenses. Newer lenses with modern cement should be less susceptible to this, but may be at risk of cracking from differential stresses from differeing thermal expansion. Remember that optical glasses are designed to perform well optically, not for similar expansion coefficients. Same with barrel materials...
250 degrees is the temp it will seperate on purpose. Car trunks in Nevada get up around 160 worse case scenario. I wouldn't want to do that to any of my old Canada balsam treasures.
In 1993 I bought a 5x7 B&L Rapid Rectilinear and a 16.5 cm Zeiss Tessar for $5 at yardsale in NE Philadelphia. I put them in the trunk of my car and discovered them years later when I finally junked the car. There was no sign of balsam failure and these lenses had lived through four summers and three winters.
In any case my fear of leaving lenses in a car has more to do with theft than balsam failure.
Maybe Bill should move to Finland.
I have my lenses in the car most of the times, and when I can(car on my sight) I Always leave the the windows rolled down, not just for the lenses, but also film, speed graphic curtain and bellows.
The lens is the least of my worries, a well separated petzval might lead to good results.
Posting Permissions
Reply With Quote
Bookmarks