Making a K-mount folder

[bhorn]

Did you ever complete this? How did mounting the lenses on K body caps work out? were they rigid enough? How did you go about cutting the holes. I currently do not want to spend the money for a drill press but have a variable speed drill, a dremel and various tools made for cutting paper/cardboard. Any suggestions?

Thanks,

Bruce

[Ian Grant]

Yes I made a first prototype about3 months ag while in the UK, I just used a metal hole cutter and a semi-circular file & fitted a couple of Copal 0 lenses/shutters to a K mount body cap. I used a 150mm Sironar & 90mm Angulon. I should have taken some photo's but it's no different to Paul Lewins in practicality, but the lenses are back in Turkey now.

Ian

[df cardwell]

Ian

Good idea. My Juwel would be a good candidate for this. Let us know how it works.

don

[bhorn]

Did you end up using metal body caps or plastic? I am thinking of trying out the plastic ones first to see if they are rigid enough. Although people posting in other threads cautioned about the dangers of using adjustable drill bits freehand, I am thinking that if I use my cordless drill at a very low speed and clamp the cap to a big piece of wood it should be safe enough just drilling through plastic. Does that seem reasonable?

I also have a strong iris and am thinking of mounting that to a K mount with a home made lens board in between. I may use an extension tube for the k mount on that one as the strong iris is huge (I think it should hold at least a #3 shutter) and that and the board together will be a bit heavy.

Does anyone know what the smallest strong irises are that were ever made? Most of my lenses are #0 or #1 at most and it would be nice to use a smaller one if I could find it. Also, any places to find them other than eBay? That is where I found this one but they don't seem to come up all that often.

Thanks,

Bruce Horn

[Ian Grant]

Plastic, if I could find metal that would be far better.

The shutter size is dependent on the speed of the lens and the size of the elements closest to the iris/shutter.

Ian

[bhorn]

That makes sense. Most of my lenses were originally designed for 4x5 or smaller and are pretty compact. the 75mm f1.9 may be a #1 or larger but it was only designed to cover 2 1/4 so it is not terribly large.