mounting a packard shutter in front of a barrel lens

[abruzzi]

Has anyone seen a clever way to mount a Packard shutter in front of a lens? Also, is there any good reason to not mount one in front of the lens? (aside, of course, from the limitations the hole diameter on the shutter places on which lenses will work.)

I had an idea to 3D print something like a Cokin/Lee square filter holder, but sized for a packard shutter. Then use the same threaded mounting disks that the Cokin system uses, or if the lens isn't threaded, 3D print a disk with a slip on collar of the right diameter. I've already drafted a 70% of model as a proof of concept. I've never done any 3D printing, but I believe we have a place in town that can slice and print my model. But before I go deep into printing, testing, and refining, I figured I'd see if anyone else has already come up with a better idea.

 

[juan]

That’s what I’ve done. I modified a Cokin P holder and glued it to the Packard. Then I make adapters from whatever and glue a Cokin plate to them. Slide the adapter onto the lens and slide the Packard onto the adapter. If my lenses have a thread I use those.

 

[abruzzi]

That’s what I’ve done. I modified a Cokin P holder and glued it to the Packard. Then I make adapters from whatever and glue a Cokin plate to them. Slide the adapter onto the lens and slide the Packard onto the adapter. If my lenses have a thread I use those.

Thanks. What size is your Packard? Mine is a #6, which is about 6 inches square. I'm having a lot of fun with this 3D modeling software I found, so if I make a successful model, I'll post it in case anyone wants to make their own. I'm designing the model based on a set of variables, so I sould be able to easily resize if for different sized Packards by just changing a few variables. I already have a Cokin P kit with lots of mounting disks--it works great on most of my 4x5 lenses. We'll see if I have to upsize to Z to support 8x10 lenses. I also thought about adding a slot or two to use the square filters with the shutter, but it probably won't work since the shutter should be the furthest back, and the piston would get in the way of mounting the filters closely.

 

[Pioneer]

I am pretty lo tech.

I cut a piece of 3/4" plywood to a square that fits the shutter, in your case about 6x6. I drill a hole in the center to just fit the barrel of the lens I want to use the shutter on. I mount the shutter to the board and then slide it onto the front of the lens. Sometimes I paint the board, sometimes not. I usually have to drill a small hole so the shutter pin that controls instant vs bulb shutter action can be slid in and out.

Not pretty but it works.

 

[btaylor]

Talk about Lo Tech- I followed Jim Galli’s tip and glued a Packard to a Planters peanut can and slipped it over my lens with some black weatherstripping to make up the gap. I will paint the can black one of these days. I like the Cokin idea a lot- seems more “professional.”

 

[Pioneer]

I like Jim's tip as well. I just hate gluing anything onto a lens or shutter.

No to sure about the Cokin filter method. It sounds good but I'll have to explore that one a bit further.

 

[jimjm]

I used some tips from Jim Galli as well, and set out in search of something to use as a "sleeve" to fit over the front of a 15 1/2 inch Wollensak lens. Only a Packard #8 shutter had a large enough opening for this lens, but the shutter housing was way too big to fit behind the lens board. Looked at some plumbing and HVAC supplies, but eventually found a perfect fit in an old kitchen gadget at home. Cut to length and painted black, I then used black epoxy to attach it to the shutter housing. It slides on and off the front of the lens easily, but gives a nice snug fit.

 

[abruzzi]

I like some of the ideas here, and it makes me more confident that my idea will work, though it will require some testing and probably a few revisions before I get it right. Obviously some of you have more skill (and tools) than me, but my skill (and day job) is writing code which is why I'm taking the approach I am. I also don't like doing anything like a permanent modification like cutting or gluing. The modeling software I'm using is all code based--you define primitives (cubes and cylinders) and combine them (union, difference, or intersection) using a definition language. As I said, if this actually works, I'm happy to let others use the model. I'll post back to this thread with progress. I thought of a way I could include a slot to add a square filter, but it would have an issue of moving the shutter a bit further from the lens, making the whole setup more likely to vignette.

How big do Packard shutters get? (the board size, specifically.) As I mentioned, mine's 6". A few people here have mentioned 8". Is that the largest?

 

[juan]

All the details on the shutter are here
https://packardshutter.com/

As for gluing, some glues are removable, so they don’t ruin the shutter.

 

[btaylor]

As for gluing, some glues are removable, so they don’t ruin the shutter.

Good point, I think I used either silicone gasket sealant or double sided tape- both non permanent.

 

[abruzzi]

As for gluing, some glues are removable, so they don’t ruin the shutter.

Its not so much that, as wanting to use a single shutter on a variety of different lenses. If what you glue it to is designed to adapt to variable size lenses then ok, but if it is a single mount for a single lens, its more restrictive than I'd want.

 

[juan]

That’s the reason for the Cokin system. Put the modified filter holder on the shutter. Make adapters out of PVC, coffee cans, kitchen stuff that will slide over the lens. Attach a Cokin ring of appropriate size to the adapter. You can then use the shutter with multiple lens.

 

[jimjm]

Yep, the glue I used was actually silicone, not epoxy, so it's removable if I need it to be. The shutter housing is 7.5" square and the aperture is 4" diameter.
If I have need for a shutter on a smaller lens, I'll just go the more common route and mount it to the rear of the lensboard, if it fits like this one does:

 

[grat]

The modeling software I'm using is all code based--you define primitives (cubes and cylinders) and combine them (union, difference, or intersection) using a definition language.

Sounds like openSCAD-- unless, gods help you, it's POVRay.

It's not quite as programmatic as openSCAD, but I like using a package called DesignSpark Mechanical-- Windows, free for personal use, pretty powerful.

 

[abruzzi]

no, its openSCAD, its actually nice for primitive based modeling. I'm not sure I'd want to use it to model a 3D dinosaur, but this just a bunch of cubes and cylinders. Unfortunately, I didn't work on the model this weekend, so nothing to post yet...