Reset Infinity

When the back of the roll film camera was replaced with another, the film plane moved a little bit back. When focusing far away (50ft or more) this is pretty negligible. But when focusing any closer, the rangefinder and the photo focus won't match.

Gotta fix that.

The Model 150, is supposed to have an adjustable focus stop with only 2 rivets instead of 4. Unfortunately, unlike my first one, this stop is fully riveted in place with no way to adjust.

So, I had to drill out all 4 rivets and glue the stop in place. Because of the large guide screws, I had to cut part of the stop, yellow line.

Most likely, you won't have to do this, so the rest of these steps deal with an adjustable stop.

Drill out the rivets, yellow arrows from the bottom. Loosen the 2 adjustment screws, red arrows.

The stop is now adjustable.

Typically, to adjust focus one would use some ground glass. But, an alternative is some tracing paper cut and taped to an empty film pack. Make sure its tight, this needs to match the film plane.

The camera needs a stable platform and a way to keep the shutter open while focusing. Grab your trusty tripod and a cable release. To keep the shutter open, you need to set the shutter to "Bulb", marked B on the front of the camera.

The best way to view an image for focus adjustment is to have the camera view something bright while the back is in darkness. A window view is a good idea.

I chose to shoot out my bedroom window. Luckily I already had some black curtains to aid in keeping the room darker than the view outside.

To aid with the darkness, I also put a black t-shirt around the camera like a hood and stuck my head into it while focusing.

Set the focus knob to infinity, make sure the shutter is set to B, and that the aperture is wide open (with EV, that's the lowest number on the dial). Use the cable release to lock the shutter open. Aim at something at least 75ft away, further is better.

The image will be upside down, you do know about optics don't you?

While keeping the focus knob set to infinity, move the front standard back and forth until you have sharp focus. If you want to be REALLY sure, use a loupe to check your focus.

Tighten the 2 screws to save your new infinity point.

You have now completed a

Model 150 packfilm conversion.

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