Shutter on enlarger lens?

[cyrus]

Has anyone tried attaching a timed shutter to their enlarger lens, instead of repeatedly turning the bulb on and off? Is there a benefit?

[Nathan Potter]

I have a Leitz enlarger with a shutter. However the shutter mechanism is mechanically decoupled from the lens using rubber vibration isolation standoffs. I use it for long exposures though (10 to 60 seconds) and see no adverse blurring on prints. I think short exposures may be problematical even with vibration isolation. Can't see any benefit over enlarger timers except maybe for short exposures.

Nate Potter, Austin TX.

[ic-racer]

Has anyone tried attaching a timed shutter to their enlarger lens, instead of repeatedly turning the bulb on and off? Is there a benefit?

It has been done. The Durst CLS1800 has a shutter. Its an incandescent head, but I believe the bulb turns on first.

It could be an advantage on a cold light also. I personally have never seen a Packard shutter used with a cold light, but I don't see why it wouldn't work, and may have some benefits.

[Bob Salomon]

The benefit to a shutter was to eliminate the color shifts that would occur as a lamp turns on and off. So labs could leave the lamp on and do the timing with the shutter. You would turn the lamp on then momentarily later make the exposure with the shutter then turn the lamp off after the shutter has closed. Enlarging lenses in shutters were also commonly used with enlargers with point light source heads.

One problem is that the 39mm thread that is used in a shutter is not the same pitch as the 39mm Leica thread used on an enlarging lens. So unless you have an adapter to switch threads or a modified shutter for Leica thread the enlarging lens will not mount directly into the shutter.
As for a 150 Apo Componon screwing directly to a 1 shutter that is a bit much. The 150mm HM Schneider, per Schneider's literature, has a 55 x 0.75 mm mounting thead. A Copal 1 shutter has a 39 x 0.75 thread mount. Screwing one into the other would not be easy without some modifications. A Copal 3 shutter, as used by Rodenstock, has a 62 x 0.75 thread. So the 150 would not screw into an unmodified 3 shutter either.

What Don might be saying is that by removing the front and rear groups from the normal enlarging lens mount it might fit into an unmodified shutter but doing that would lose any enlarging lens features like click stops, illuminated aperture scales and pre-set aperture rings.

On special request the lens companies will supply enlarging lenses in shutter and as a virtually everyday item they also supply helicoid focus mounts for the enlarging lenses in regular mounts.

[Sevo]

The benefit to a shutter was to eliminate the color shifts that would occur as a lamp turns on and off. So labs could leave the lamp on and do the timing with the shutter. You would turn the lamp on then momentarily later make the exposure with the shutter then turn the lamp off after the shutter has closed.

Yep - some pro lab timers could be equipped with a separate control output to drive a magnetic shutter in such a setting.

Enlarging lenses in shutters were also commonly used with enlargers with point light source heads.

As well as all other types of arc, mercury or metal halide lamps - due to warmup and hot start issues, they cannot be run on a timer. To protect the film against light and heat, these were usually shuttered somewhere between light source and film plane (with flap or window blinds type shutters), though.

Sevo

[Don Hutton]

As for a 150 Apo Componon screwing directly to a 1 shutter that is a bit much. The 150mm HM Schneider, per Schneider's literature, has a 55 x 0.75 mm mounting thead. A Copal 1 shutter has a 39 x 0.75 thread mount. Screwing one into the other would not be easy without some modifications. A Copal 3 shutter, as used by Rodenstock, has a 62 x 0.75 thread. So the 150 would not screw into an unmodified 3 shutter either.

What Don might be saying is that by removing the front and rear groups from the normal enlarging lens mount it might fit into an unmodified shutter but doing that would lose any enlarging lens features like click stops, illuminated aperture scales and pre-set aperture rings.

What I said was that the lens elements are a direct fit into a Copal 1 shutter and they are. You unscrew them from the enlarging barrel and screw them into a Copal 1 shutter - is that clear enough? For a moment, I'd just presumed that we were all adults.