PINHOLE BOBYCAP

[RalphLambrecht]

dear Apugers,
I am looking for a pinhole body cap that would fit my Hasselblad 500.
If possible in the EEC.
It looks that in the U.S. this is rather common to find; the same on eBay, but there it is quite costly to get it shipped (and custom's duty are too) to Belgium.
But over here, in Europe, most of the shops I could find on the internet ran out of stock, for the Hasselblad V at least...
Any suggestions?

Thanks,

makw your own

 

[AgX]

... I'm sure one could use a micro-drill, unless one has an appropriate precision high speed drill press and a means to clamp the extremely thin stock, ...

There is no reason to use a drill press. Moreover those typically do not accept so tiny diameter drill bits. These are better used in handheld drills.

 

[Yukon Alvin]

I have made hundreds of pinhole for workshops i used to lead. Pop cans works, i like brass shims like Donald said. The trick is to us a ball point pen and tap it on the shim or can, you get a divot on the back side, flip it and use sand paper to sand said divot. Now you have a lot less material to go through.
Using a sewing needle that you flat sand on one side ( think drill bit now) i glue them onto clothes pin with epoxy, cut the top of needle a bit shorter with snips, put you finger on top of the needle and flick the cloth pin (manual drill)...
A size #10 sewing needle will give you 0.46mm- size 12 0.= 36 ( its an art form not a science) .
Make multiple version that can be identified, try them all see what you like. Sometime less than perfect pinhole give you the best results.
Have fun

 

[DWThomas]

There is no reason to use a drill press. Moreover those typically do not accept so tiny diameter drill bits. These are better used in handheld drills.

Hmm -- "back in the day" I was involved with electronic gear and occasionally do-it-yourself printed circuit boards. We used drill press like tools -- one perhaps called a "sensitive drill" that had a small chuck that could hold drills down to sewing needle size. (A #80 drill bit is 0.0135 inches/0.343 mm) The motor head and the chuck stayed at a set level and the table, maybe 6 or 8 cm in diameter was raised by a rack and pinion mechanism using a knob on the side. The motors cranked at quite high speed -- like 10 to 20K RPM as I recall. (Here is a sample) I have also seen and used a device ("sensitive drill feed") that chucks in a more normal sized drill press but has a precision chuck on a spring loaded splined sliding shaft. Just above the chuck is a collar on a bearing that you can grasp with a thumb and a finger and pull the drill down. (One flavor here) Obviously if the main drill press has horrible run-out it will be a waste of time. That sort of chuck gives more of a chance to feel the relatively light contact pressures needed.

My main point is fractional millimeter drills are fragile and springy and I would expect results to be little better than the dimple-and-sand method unless one had some fancy (and expensive) precision equipment available. I can't imagine trying to do it with a hand drill. I suppose the best candidate there might be hand twisting a "pin vise" but it all seems just as tedious as dimple and sand. In fact I do use a pin vise to hold the needle I use to press a dimple. Fortunately you only need one if it comes out right!

But hey, whatever works for whoever is doing it!

 

[Yukon Alvin]

My main point is fractional millimeter drills are fragile and springy and I would expect results to be little better than the dimple-and-sand method unless one had some fancy (and expensive) precision equipment available.

Like i said its an art form not a science. I do have some micro drill bits and a jeweler finger drill but the results are no better or equal to the sewing needles.
The fun thing about "dirty holes" as we called them vs laser drill pinhole is that sometime you get shards and other materials left in the pinhole. Just enough to bend a particle of light and get some nice colours (colors) or/and light anomalies. Pinhole are supposed to take us away from perfect glass with aberrations, a Blad lens can do that, pinhole are something else.

 

[Philippe-Georges]

Thank you all for the sometimes elaborated advices!
Below is a link to my website page (called diffraction) where you can see some pinhole photo's made whit a Robert Rigby 4"x5" pinhole camera.
The reason I was looking for a Hasselblad body cap is that I am solely using that camera now.
diffraction

 

[RalphLambrecht]

I have made hundreds of pinhole for workshops i used to lead. Pop cans works, i like brass shims like Donald said. The trick is to us a ball point pen and tap it on the shim or can, you get a divot on the back side, flip it and use sand paper to sand said divot. Now you have a lot less material to go through.
Using a sewing needle that you flat sand on one side ( think drill bit now) i glue them onto clothes pin with epoxy, cut the top of needle a bit shorter with snips, put you finger on top of the needle and flick the cloth pin (manual drill)...
A size #10 sewing needle will give you 0.46mm- size 12 0.= 36 ( its an art form not a science) .
Make multiple version that can be identified, try them all see what you like. Sometime less than perfect pinhole give you the best results.
Have fun

dito. I'd just use a ball-point pen followed by a needle!