The importance of lens caps?

acjeske

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I'm new to film Leicas. I see some people saying lens caps are essential so you don't burn a whole in the cloth shutter. Is this true? Do y'all always keep a lens cap on?

That's not my normal style, so I'm hoping some of you don't always cap 'em...
 
For one of the similar posts I was able to find it in the film M manual. Feel free to find and read it as well. 🙂

Repeating the same, as usual. Yes, I burned curtain within three minutes while keeping @f1.5 on bright day and white snow.

Keep aperture at minimum, do not point to the sun while on walk or yakking by the table.

During normal, Canadian winter I put cap on before entering inside. To prevent condensation on the filter.

No filter, no cap is trashier style, IMO.
 
I'm not afraid to admit that I use a protective filters on all my lenses for peace of mind. I never use a lens cap except perhaps when storing the lens.
I am conscious of the effect of sunlight hitting the cloth shutter of a Leica through the lens, but I have never experienced that it has caused burning a hole.
You do have to be aware, though.
If you put your camera on a sunny café table @noon lens facing upwards and focused at infinity, then you'll burn a hole in seconds.
Under these circumstances, I'll either keep it on my shoulder or put it in my bag.
 
I'm new to film Leicas. I see some people saying lens caps are essential so you don't burn a whole in the cloth shutter. Is this true? Do y'all always keep a lens cap on?

That's not my normal style, so I'm hoping some of you don't always cap 'em...

Most would use a UV or Skylight filter and a proper lens hood on the lenses...I certainly do on my M mount lenses.

An exception is on the Barnack Leicas ...as it is common for users not to have a filter and a lens hood for the 50mm Elmar lens and protect the lens when the camera is not in use by a lens cap....I think this is more to do that filters and proper lens hoods for the 50mm f3.5 Elmar are hard to find these days and a bit expensive to buy when found.

Any RF camera with cloth shutter curtains has to be protected from the sun burning holes in the shutter material...not always possible but it should be on our minds when using these cameras and proper precaution should be taken.
 
I usually put a lens cap on in bright sun but I'm not too zealous about it.

Roger Hicks & Frances Schultz address this in their rangefinder book. I believe their conclusion (based on testing) was that you would have to make an effort to burn a hole in the cloth shutter.
 
I use what Roger recommended years ago, neoprene “hood hats” that fit over the lens hood. Just leave the hood mounted on the lens and slip the “hat” on or off as needed.
 
I put this theory to the test on some shuttercloth offcuts years ago. There's a thread on here somewhere (along with others).


Yes, it can be done BUT you need a) a fast lens fairly wide open b) to focus the sun accurately on the cloth and c) deliberate aim at the sun, preferably midday-ish and summer and d) several seconds if the lens is past about f/8.


Given the chances of doing it accidentally, I'm just mindful of the possibility but not be overly-worried. You'd need to be pretty careless, although it's definitely happened to some people.
 
And I asked a (retired) technician if he had ever seen a shutter blind that had been burnt this way and the answer was that he'd seen several.


Regards, David
 
I use a UV filter and the cap on my 8 ele cron and also set the lens to f16. Even with the hood on my cron i have a china made cap for it. That being said all of my leica lens caps are really beat up from nudging them off while walking and them bouncing off the floor.
 
If you’re worried about the Sun, just defocus the lens to about 3’ while walking around.

I don’t bother with lens caps nor do anything special other than always being mindful about where the lens is pointed. However, I always carry my camera in hand rather than hang it off me by the strap.

Also, we don’t have sunshine here.
 
If you’re worried about the Sun, just defocus the lens to about 3’ while walking around.

This may not be a safe thing to depend on. Since the curtain is in front of the film, focusing the lens closer might focus the sun more accurately on the curtain than if left on infinity, with a greater risk of burning the shutter.
 
I'm new to film Leicas. I see some people saying lens caps are essential so you don't burn a whole in the cloth shutter. Is this true? Do y'all always keep a lens cap on?

Nope. I haven’t used a lens cap since I got my M2 7 years ago. No holes in the shutter.

*edit* I don’t know why there’s a thumbs down for my comment title?
 
This may not be a safe thing to depend on. Since the curtain is in front of the film, focusing the lens closer might focus the sun more accurately on the curtain than if left on infinity, with a greater risk of burning the shutter.


OK, for those that like to keep the lens at f/16, try 1.5 feet. At a 1.5’ focus distance, the image of the Sun on either the film or the focal plane shutter will be a very big out-of-focus blob with much less heat.

If this is a hassle and your choice is a lens cap, it helps to put tape or some object on the cap so that a capped lens is visible in the viewfinder.
 
When I am out with the intention of taking photos I do not have the lens cap on my Leica M (and other cameras) as I want to be ready and not miss any opportunities. However, when storing my lens +/- camera in the bag I usually put a cap on. I use a lens hood on all lenses as it provides some physical protection as well as reducing extraneous light hitting the lens.
 
Not really a consensus here, but I'm going to reset my lenses to MFD and stop them down between shots and not sweat a cap all the time. Thanks for all the replies.

Oh, I do have one other question...do UV filters mitigate this risk of burning a shutter? Some seem to indicate yes, and others indicated this is contentious...
 
Not really a consensus here, but I'm going to reset my lenses to MFD and stop them down between shots and not sweat a cap all the time. Thanks for all the replies.

Oh, I do have one other question...do UV filters mitigate this risk of burning a shutter? Some seem to indicate yes, and others indicated this is contentious...

My post up top referred more to the fact that lens cap discussion risks dissolving into two entrenched groups: those that want to be ready to take every photographic opportunity that passes their, and those concerned the sun will burn through their shutter.

The apotheosis of this type of discussion can be UV filters: some believe in the protective powers of UV filters at keeping dust and dirt off your lenses, others believe that they will severely degrade image quality and never be seen with them. As is often the case online: YMMV.

A UV filter will not save your shutter curtains from the sun - on that, I suspect, we will all agree!:angel:
 
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