Older Shutters - Accurate?

Hi all,

I've got a Voightlander Heliar 13.5cm / f4.5 lens, Compur shutter (T, 1-1/200 speeds). A McCeowns (spelling) guide from the local library gives 1912 as the year when this lens / shutter was introduced. It's mounted on a Burke & James Press camera, and was CLA'd after I bought the whole unit off Ebay.

Optics are good, and I like the look when I get the exposure right.

But I find I'm underexposing on the slower speeds, ie, shutter seems a bit fast based on Polaroid film I bought for learning.

I assume my meter is accurate, because when I use it with color film in my other cameras, it never lets me down.

So my question:
Are these old shutters generally accurate after a CLA, or not neccesarily?

Perhaps it didn't matter much back in the day when they were new?

If the answer is that I have to take test shots on Polaroid and see what comes out, I can do that. Above question is prefaced by "generally"...

Thanks!

Usually they're slow. I don't think even brand new mechanical shutters are ever 100% perfect speed wise. There will be a range of acceptable.

I find the older shutters are seldom as accurate as a modern Copal shutter. The faster speeds are almost always slow. Consider yourself lucky if you can get plus/minus one-half stop accuracy.

Cool.

Mine seems fairly accurate at the faster speeds, but fast at slow speeds.

I think I will maybe shoot some test shots in Polaroid to calibrate how far off it is (probably just every other speed), and then just compensate for it.

Half-tempted to buy that electronic shutter-speed tester and check it out, as I have more than one camera, and I imagine that could be useful.

Thanks, people!

Dial-set Compur shutters are sometimes both slow at the faster times and fast at the slow times. A CLA will fix both, since both are a result of "gunk" in the works.