no lens cap; does it matter?

[jl-lb.ms]

Hi,

I have a new Bessa T on the way and wanted to also use a Leitz 35 on it. I have the right finder, but no lens cap. Is there much danger of burning up the shutter curtain this way?

thanks,

john

 

[back alley]

i never use lens caps.

with a cloth shutter there is always a potential for burning and while i have read of a few cases; there were not many.
keep the standard precautions in mind and you should be ok.

 

[back alley]

Hi John,

on a Leica yes, on a Bessa T no, it has a metal shutter.

Roland.

doh!


😉

 

[aad]

I've heard the story about burning cloth shutters, so I took an Elamr and Sumarit and tried projecting the sun on the back of my hand. Short answer-don't worry about it-unless you plan on keeping the camera pointed at the sun for a year.

 

[pvdhaar]

Indeed, the T has a metal shutter. In fact is has two sets of shutter blades. The purpose is to prevent light leaking through a single set of blades. In SLRs, that role of the second set is performed by the mirror instead.

As to burning a hole into a cloth curtain, that won't happen when the lens is focussed at infinity.. The shutter cloth sits a bit in front of the film where the focal point lies, so it won't catch the most concentrated light. Only when the lens is extended a bit (focussed closer) will the focal point for sunlight be at the shutter itself..

 

[ddutchison]

I've heard the story about burning cloth shutters, so I took an Elamr and Sumarit and tried projecting the sun on the back of my hand. Short answer-don't worry about it-unless you plan on keeping the camera pointed at the sun for a year.

I'm sorry to have to disagree (Perhaps it was a cloudy day in Massachusetts when you tried this🙂 ), but this is very dangerous advise to give to anyone using a cloth curtained RF camera.

Please check out laptoprob's thread. He tested this out using a sacrificial Zorki. With a wide open f2 lens it took about a second to burn a hole in the curtain.

For a discussion in more detail than you could imagine (including how much -or little- focussing at infinity protects you), there's this thread on photo net.

Personally, I carry a camera over my shoulder, so I just use my arm to cover the lenshood when it's sunny.