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View Full Version : Shutter left cocked or not


Anthony Harvey
05-10-2008, 12:19
I hesitate to raise this matter - at first sight it seems so trivial - but if one takes the view that the shutter should always be left uncocked then on many occasions one is committed to firing blanks or shooting a half-hearted shot before one puts the camera away.

Roger, I wonder what your policy is and the thinking behind it? Do you leave the shutter tensioned when you know the camera will be put aside for perhaps a week or more, or even for longer if itís a camera in your collection? And Tom (Abrahamsson) with his large collection?

Photography has been a great interest of mine from quite an early age, perhaps even from around ten, and at some time or other (and Iíve long since forgotten when) I must have made the policy decision that if Iím about to put the camera aside for what might be a fair bit and the shutter is tensioned I fire a blank. Of course, I imagine that a heavy user wouldnít give it a momentís thought one way or the other but my thinking as an enthusiast has been that if I repeatedly leave it tensioned between shooting sessions then over a period of years it might in some way weaken the spring mechanism. Of course, Iíve no doubt that the manual shutter of the Leica is so well engineered that leaving it tensioned wouldnít make any difference to its accuracy and reliability but I canít help wondering if it wouldnít be better to leave it untensioned, a sort of better safe than sorry approach.

I suppose I mollycoddle my cameras to some extent, and you might take the view that this is just a silly example of it, but I suspect that there might be a few others on this forum who at least think about the matter from time to time, whether or not it bothers them to any degree.

Having made this policy decision in my early days of photography I have never really questioned it much but itís begun to occur to me a lot recently for two reasons. First, having returned to rangefinders after years with automatic cameras I find that the meters on both my R3M and M7 will only work with the film wound on, so if I want to take a reading without taking another shot Iím faced with the option of firing a blank or not. Secondly, when researching the M7 before buying one, I noted many comments (including a direct reference in the M7 manual itself) that one of the benefits of an on-off switch is that it can prevent the shutter from being accidentally fired if the camera moves about in the camera bag, thus implying that many photographers will put their cameras away with the shutter tensioned.

Anthony

cosmonaut
05-10-2008, 12:39
I am unsure of long term damage to anything but don't store mine cocked. Maybe a poll?

Roger Hicks
05-10-2008, 12:41
Dear Antony,

From all I've heard, and from 40+ years experience, I don't think it matters at all.

Having said that, I normally store cameras with the shutters uncocked, because if I leave a camera loaded for more than a few weeks, I'll probably forget what I shot on it. I therefore wind the film off and either process it myself (mono or slide) or get it processed (colour neg).

But to contradict myself again, every now and then I'll come across a camera I've left loaded (and normally cocked) and I've never had a problem yet. I suspect that the 'weak spring' problems (as on my 45-year-old Pentax SV) are sheer wear and cumulative weakening, rather than being left under tension. A possible exception is the top 1/500-1/400 speed on Compur and similar shutters (supplementary spring) but you can remove this concern by switching to 1/250 or lower.

From other areas completely (old houses, my BMW motorcycle) I know full well that very low loads, repeatedly applied, can deform metal that should, in theory, resist all deformation from such low stresses, so I am convinced that it is repeated use, not being stored cocked, that leads to loss of spring tension.

I have to say, though, that I am not a metallurgist, and I could be completely wrong -- though engineers who know far more than I are often of the same opinion I am, and most of the others say (with complete honesty) that they don't know. Only a very few hedge their bets by saying that a badly tempered spring under excess tension might die...

Cheers,

Roger

Steve Litt
05-10-2008, 13:37
I used to wonder about this until I got a Rollei 35s and found you cant close the lens unless the shutter is cocked.So I believe it to be ok.Having said that apart from the Rolllei mostly I keep my cameras uncocked unless I am using them- out of habit.

Regards
Steve

Pablito
05-10-2008, 14:00
Since half the experts say to leave it cocked and half say not to leave it cocked I leave it cocked half the time and leave it uncocked the other half of the time. Or something like that.

Gumby
05-10-2008, 14:42
From all I've heard, and from 40+ years experience, I don't think it matters at all. ... though engineers who know far more than I are often of the same opinion I am...


This is my experience, and understanding, as well.

MartinP
05-10-2008, 16:32
Roger had a good point about the between-lens shutters and the extra springs that may be involved when set to fast speeds, but I recall there was an explanation (on Rick Olesen's site?) that the difference in tension between the wound and unwound positions of a Leica focal-plane shutter was not much.

Basically they are always under some tension, even when released, as the curtain movement does not result in a "floppy" spring only a "slightly-less-tight" one.

So, that takes care of two types of shutter - just three zillion to go . . . .

aad
05-10-2008, 16:48
You do realise that all auto-wind cameras always have cocked shutters.

That said, I too generally keep the shutter uncocked. That way I always wind before trying to make a photo.

SolaresLarrave
05-10-2008, 17:03
Super auto cameras also have electronic shutters.

My Leicas have mechanical stuff. Hence, I prefer to leave them unready.

I like Pablito's approach, though. Good policy! :)

Chriscrawfordphoto
05-10-2008, 17:13
Electronic shutters in modern autofocus, autowind cameras do not usually use springs to drive them. The shutters are driven by solonoids, so there is no tension. The older electronic shutters, like in the Olympus OM-2 and 4, and the Nikon F3, are spring driven and electronically timed.

wontonny
05-10-2008, 17:28
I started a thread like this once. Someone told me that Leica did experiments to see how long a shutter would stay cocked. They cocked one before WW2 and left it until the end of the war and it fired accurately.

I leave mine cocked, I'd rather have an accidental firing while it's being stored than want to press the shutter and have nothing happen and miss the moment.

literiter
05-10-2008, 17:47
I think Hasselblad thinks it's OK, probably because you can't change lenses if they aren't cocked, but if possible I leave my cameras uncocked.

JeffGreene
05-10-2008, 18:52
The same is true for Rollei. My Rollei SL66 is the same. When the camera first came out, it developed an undeserved reputation for unreliability because people failed to always cock the shutter prior to removing the back.

wallace
05-10-2008, 22:16
The shutter of the Fuji GS645 folder needs to be cocked before you
close the camera!

Tom A
05-12-2008, 13:40
My experience with cocked/uncocked shutters is that it really does not matter if you are thinking in terms of days and weeks. If I would have to "lay up" a camera for longer time I would make it a habit to cycle through all speeds at least once a month.
On problem that is common is that as you shot a frame, advance (cock the shutter) and leave next frame ready to go and leave the camera sitting for an extended time (days-weeks) - there is a chance that the "frame" that is sitting in the filmgate can buckle slightly (gravity, change of humidity, thickness of filmbase etc) and when you grab the camera and fire - it can appear out of focus! This is particularly true with fast lenses - a 35/1,4, a Noctilux or the 75f1.4 where you are dealing with minute depth of field at the best of time.
I use my Softrelease on virtually all the cameras that are in use. This fixes the problem as everytime you drop it into the bag, it goes "click" and you have that nice,black shot of the messy interior of the Brady bag! One day I will print up a series of black and whites, 11x14, nice borders and all - and solid black only, with occasional stray light from the bag having been left open as you dumped the camera in with the lens facing up! "From Inside My Camera Bag" project!

drewbarb
05-12-2008, 14:16
It's my understanding that the Leica shutter uses very low sprint tension, and the difference between cocked and uncocked is not much, in terms of spring tension, so with this shutter it doesn't matter. I also remember being told years ago the the mechanical shutters in my Nikons were better off being stored for any real length of time uncocked.

Hence, with the Leicas, I don't worry about it; I store the Nikons uncocked mostly, but occasionally pick one up that I haven't used in a while and find it cocked. Whatever the case, I've never yet had a shutter problem in any camera that was ever even potentially traced to this issue. I tend to try to leave my cameras uncocked- and as Tom points out, they tend to get fired accidentally when I leave them cocked (with or without softies)- so when I pick up my cameras and am getting ready to shoot, I habitually pull out the crank and cock it, or try to, to be sure I am ready with a cocked shutter and fresh frame before I want to shoot.

kennethcooke
05-26-2008, 11:31
Tom A quotes- I use my Softrelease on virtually all the cameras that are in use. This fixes the problem as everytime you drop it into the bag, it goes "click" and you have that nice,black shot of the messy interior of the Brady bag! One day I will print up a series of black and whites, 11x14, nice borders and all - and solid black only, with occasional stray light from the bag having been left open as you dumped the camera in with the lens facing up! "From Inside My Camera Bag" project!.

I guess it makes sense to leave rangefinder cameras uncocked so as we don't end up with the problem Tom A highlights. One would never leave a shotgun cocked because it leaves the mechanism under tension so I guess the same is true with RF cameras

BillP
05-26-2008, 11:43
Cocked, every time.

I'd rather not miss the shot. Springs are under tension whether the shutter is cocked or not, after all. It's never caused me a problem beside approximately one shot wasted per roll.

Regards,

Bill

Ben Z
06-03-2008, 10:21
I have never been able to make up my mind so I just cock it halfway.

My dad used to warn me about going off half cocked.

Turtle
06-03-2008, 21:14
I know from spring powered air rifles (back in the mid 90s) that if you leave them cocked for a long period they will lose power very substantially unless the main spring is a rather special and more expensive one. I have seen tests where an air rifle left cocked for a month loses almost half its power, but where custom aftermarket and more expensive springs are just fine after the same abuse. I guess it depends on the metal.

I release my shutters to be sure, but once in a while have come across a cocked LF lens or other camera and it has made no difference.

payasam
06-04-2008, 11:21
Using the air rifle reasoning and to avoid accidental blank exposures, I try to store cameras with shutters not cocked. With focal plane shutters, though -- on RF or SLR cameras -- I understand it makes little difference either way. One of the first things I was taught about the Rolleicord I began to use in the early 1960s was never to leave the shutter cocked. "Dry firing" that camera needed only a lens cap, as shutter tensioning and film winding were independent operations.