What causes dragging slow shutter speeds on old camera?

[Forest_rain]

I noticed that often when looking at old cameras, the seller will note that "slow shutter speeds are slow". This seems like a common issue with older cameras, is this an easy fix? Usually it is slower speeds like 1 second or so.


Just curious or if this just involves cleaning the shutter mechanism/gears or if it is indicative of bigger issues.

 

[Mackinaw]

Slow speeds are usually controlled by a separate mechanism, which usually involves a lot of springs, and gears spinning around to control timing. After decades of use, dirt gets in the gear train and/or the lubricant gets old. Both of these together cause the slow speeds to slow, or stick. Usually a fairly easy fix, just clean out the gear train.

Jim B.

 

[Ko.Fe.]

Not an easy fix with rangefinder cameras equipped with curtains shutter.
Less difficult with leafs shutters. But you still have to take shutter off, remove lens and wash, re-lube it. And put it all back.

 

[Forest_rain]

Slow speeds are usually controlled by a separate mechanism, which usually involves a lot of springs, and gears spinning around to control timing. After decades of use, dirt gets in the gear train and/or the lubricant gets old. Both of these together cause the slow speeds to slow, or stick. Usually a fairly easy fix, just clean out the gear train.

Jim B.

Thanks for reply. Will check it out, looking at some videos it looks like it's pretty simple to clean out that specific mechanism with some solvent and specific lubrication type.

 

[Forest_rain]

I asked about this on reddit, and received a message from a professional shutter repair person never to "flush" out a shutter. Is this correct?

I was thinking about "flushing" the shutter gears with cleaning solvent, after removing the shutter assembly, as I've heard this works.

However it seems like it may be better to strip down the parts, clean manually, or just clean the visible parts of the shutter gears with a q-tip and relube.

He says you should NEVER "flush" your shutter out. However I feel like this could be done gently, if used sparingly with some skill.

"Sorry, let me go ahead and reword my answer. Under no circumstances, should any leaf shutter ever be "flushed out" with any kind of solvent, or liquid. Flushing out in any way shape or form, will not be good for the shutter. In time it will cause damage. I'm afraid to say to you, that you really can't remove the shutter without a significant teardown.
​
So please, heed my warning and DO NOT flush the shutter out with anything."

 

[retinax]

You'll get different opinions on flushing whole shutters here, too. Of course that is leaf shutters. Can't flush a focal plane shutter. I say don't. If you have the shutter out, might as well take it apart. Not to the cogs and springs level, but the parts that need cleaning are usually the shutter blades, and the slow speed escapement. The escapements usually come out as a unit, and said unit can be immersed in a solvent. I don't think any repair person takes them apart, that would be serious watchmaker's work. Shutter blades are doable for amateurs with steady hands and lots of patience getting them back together.

 

[Mackinaw]

I asked about this on reddit, and received a message from a professional shutter repair person never to "flush" out a shutter. Is this correct? I was thinking about "flushing" the shutter gears with cleaning solvent, after removing the shutter assembly, as I've heard this works.

I have an old leaf shutter for the 135mm lens on my old 4x5 Crown Graphic. Fast speeds were okay, the slow speeds didn’t work. During our Covid lockdown, I had the time to take the lens apart by removing the optics and placing the entire shutter assembly in a bowl of lighter fluid for a few hours. Periodically I would swish around the bowl and fire the shutter. I noticed that the lighter fluid was slowly becoming dirty. I then pulled out the shutter assembly and dried it. It now works like it is brand new. All the shutter speeds from fast to slow work fine. I did apply a bit of light oil to certain pivot points.

Jim B.