Has anyone gone to the trouble of subjecting one of these shutters to a proper electronic test.
They don't have any slow speeds, just 25th, 50th and 100th sec.
I liberated one from a camera for its Bausch & Lomb R.R. lens.
How far off the mark did you find your example to be?
We'll never know just how good a new one ever was.
Mine on an atographic brownie is pretty close. The 1/25 is more like 1/30. The 1/50th is close enought I don't bother to compensate. The 1/100 is erratic. It ranges from 1/65th to 1/125th so using that speed is a crapshoot. Execising it doesn't help, either.
The one I tried to calibrate 35 years ago was quite inaccurate at first, and not really good after I tinkered with it for a while. They did suffice for many Kodak photographers with Verichrome film developed to low contrast, though.
I've found most of them fire at 1/25 to 1/30 at all speeds. They don't have a retard mechanism, but use one or two springs, depending on the model, that are under tension that varies by setting the speed lever. Not hard to do minor adjustments by slightly bending the spring(s). If you take it apart, be very careful not to let the ball bearings surrounding the blade mount escape. They WILL jump out and hide, never to be seen again. Just be aware that they are going to rarely be accurate. The lens, however, makes it all worth while. Sharp! Should cover 4X5 straight on.
What's 25th 50th and 100th sec in milliseconds?
My ball bearing shutter houses a B&L Rapid Rectilinear of approx 105mm focus.
It was from a Autographic Junior 1a 2 1/4" x 4 1/4" on 116 roll. If mine is defecient in speed it would not be surprising, because 116 film hasn't been available commercially for a very long while, goodness knows about the Autographic 116 type.
No way will this b****r cover 4x5 well, but i'm still going to try it anyway.
The Autographics seem quite common, so breaking up a bad one for it's lens isn't a Capital offence.
There is a source of 116 film, I think. If mine had got good bellows I might have been tempted to get a roll.
Since "milli-" means 1/1000, that's 40, 20 and 10 milliseconds respectively.Originally Posted by Neil Purling
100th & 50th aren't too bad speed wise, but 25th fires at 50th. Not bad for such a basic shutter.
Neil, 105mm seems awfully short for 116. Normal is somewhere around 130mm+. If you would like to shoot 116, why not look for some 70mm film and spool your own? All you need is used backing paper and spools. I have done that and it's not hard to do.
The only mark on the lens is "BAUSCH & LOMB"
You are right about the likely focal length. I measured out the frame, and I make it around 120mm. A R.R. lens of that focal length should cover the 2 1/4 x 4 1/4 frame wide open (f8) and throw a circle between 125 & 139mm, depending on whether it is wide open or stopped down.
The camera's bellows were no longer light tight, which made me feel less guilty about taking the lens for re-use.
I could get another Autographic Junior 1a if I wanted. I am sure there's a American business that does 116 film. Possibly with processing.
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