Cambo monorail - barrel lens/packard shutter MOD

[Ash]

I'm not the first to do it, and I hope I'm not the last, but maybe posting this will help someone else who needs an idea of how to mount old barrel lenses onto a newer camera.


Right, so the Cambo Monorail, nice camera, no lens on it.
Got some barrel lenses
Got a Packard shutter
Got some bolts



Now to put it all together.



Drilling each corner of the Cambo lens panel, and making the corner holes of the packard shutter a little larger, the shutter sits firm on top of the panel. The diameter of the shutter and lens panel opening are exactly the same. Freaky huh?

The lens now needs to sit on top. Out comes the mdf, jig, drill, etc.

First the block is cut to the size of the shutter.
The piston area is cut out, to allow travel.
Clamping the wood on with shutter on top, holes are drilled in the corners.

Now here's the annoying bit. The Packard shutter is not 'ideal'. The face has screw heads and the nipple for instant shutter. These had to be marked, and wells drilled on the underside to allow the block to sit flush on top of the shutter.

Lens is drawn around, and hole is cut for it to be screwed directly into the wood (or using tape around the thread in case hole in a little larger) - If a mounting flange is available that can be screwed onto the mdf panel, but in my case trial and good old error.

[Ash]

From this point on it's easy. All the pieces sit happily on top of each other. Everything SHOULD sit flush, and bolts can be tightened with nuts and away we go!





This method allows barrel lenses to be interchanged on a single lens panel.

[David Karp]

Ash,

Very cool. Why not convert this to an article and include it on the main site? Check with Tuan, I am sure he would like to add it there.

[dazedgonebye]

Pardon my deep ignorance Ash, but what exactly did you accomplish here?

[Ash]

dazed, nice to see you on here too!

New lenses (costly) have built in shutters, and standard threads (Copal sizes on lens panels for example).

Old barrel lenses (cheap-ish) have no shutter. That means you either use a lens cap, or your hat, or hand, as a shutter. Basic external shutters like the Packard were invented, but have to be permanently attached in front or behind a single lens.

The Cambo arrived with one lens panel, so I could either buy one single expensive lens (about 3 times the cost of the camera) and use that on the panel, or modify the panel to allow more than one lens. AND have a shutter.


With this mod I can use old barrel lenses, that are usually in odd thread sizes, with a shutter, on a modern 4x5 camera.


david, depending on the response this gets, and whether there is enough interest, I will re-write it and could provide it as an article. I'd prefer to wait until I've at least painted the MDF so a final image of the mod looks nicer.


I meant to add, the bolts were 'Slot Screws and Nuts', M4 x 50mm. Zinc plated. The nuts don't have the plastic to lock them in place, so they can be screwed in and tightened by hand.

[MenacingTourist]

Ash,

I've been kicking this problem around in my head for a while. Nice to see a solution. It reminds me to be more of a "doer", rather than overthinking things to death

Good job.

Alan.

[Ash]

Alan, I'd been thinking of how to solve it since December, and it took an hour or so of me and my neighbour staring blankly at the pieces to work out the solution.

I'd envisaged a different method, which would work on a 5x7 or 10x8 or larger camera. The lens mounts in the lens panel, and the shutter is bolted to a box-type frame behind - then if you have a deep-receding lens (where the rear element is maybe a couple inches from the mounting flange) the shutter is moved along the bolts to accomodate. Much more technical, much more hassle, and not nearly as easy to interchange lenses. With this method you can see in the first post, a largely receding lens (like my Ross Xpress) can be attached to a thicker wooden block and the rear element will always be flush with the shutter.

[Ash]

Few more pics, when attached to the Cambo

Front


Side


4x5 back removed, view of shutter closed


Those screws will need to be painted matte black, of course.

[Greyhoundman]

You could buy a Industar 37/ 300mm lens from the FSU. It has apertures from 4.5 to 64.
I use one with a Packard on both my home built and my field camera.

[Ash]

I'll look into that. I forgot all about the long focal length FSU lenses