Making a weeeery, weeeery small hole

[xwhatsit]

Wei wei,

I'm playing around with pin-hole cameras and fun stuff like that. Anyway, there's a mathematical equation to what is the best size of pinhole to use for a certain distance from film to hole. For my chosen 8cm focal length, it works out that for the best quality, I really need a hole just a shade under 0.4mm. A poke with a needle really doesn't cut it (unless you're Disco Dan's shag -- or so he hopes ).

So, what's the best way to punch a 0.4mm hole into a piece of thin aluminium (paint can if you must know)? Preferably without burrs, and remaining as close to perfectly circular as you can get.

[Gremlin]

nail?

grr fucken blah

[Sam I Am]

hey i know just a little about this the main trick is use the thinnest metal you can aluminum foil is thicker than you need i think they may even use gold leaf?

you can buy the perfect thing ..just the hole in metal on the web some were ? maybe ebay ( sort of out of sprit of making a camera )

yes just tape your thin metal ( with pre punched hole ) over a larger hole in your box/tin

and yes its a tiny hole

but i didn't think distance of lens had anything to do with it just the smaler the hole the more depth of field you get and longer exposures

best of luck

oh also if you want large pinhole prints wheelie bins make wicked portable pinhole cameras

[xwhatsit]

Well ideally you tailor the size of the hole to how far away the film/paper is from the aperture. The image has more resolution/definition if you get the size of the hole right. Pinhole lenses by their very nature have infinite depth of field (apart from super-close objects), so that's not an issue -- but if you use a much too big size hole for the distance between film and lens, you get a blurry image without definition (everything's blurry, nothing's in focus). On the other hand if the hole is much too small for the distance you chose, I believe the image will be very dark and equate to a huge f-stop, meaning you'll have to leave it to expose for a few hours if it's cloudy.

I'll look around for this pre-punched stuff.

I'd like to make the hole myself, directly in the pain tin though, mainly for robustness and simplicity. If possible.

[Steam]

... in the pain tin ...

A pain tin... is that the same as a can of whoop-arse? I'll have a gross please.

[BMW]

use tin fool and pope that hole using a grade of wire.

[twinkle]

So, what's the best way to punch a 0.4mm hole into a piece of thin aluminium (paint can if you must know)? Preferably without burrs, and remaining as close to perfectly circular as you can get.

Ring a model shop, they have stupidly small drill bits for exactly this sort of thing I needed one to drill the brake disks in my model Ducati.

[The Stranger:Me]

Wei wei,

I'm playing around with pin-hole cameras and fun stuff like that. Anyway, there's a mathematical equation to what is the best size of pinhole to use for a certain distance from film to hole. For my chosen 8cm focal length, it works out that for the best quality, I really need a hole just a shade under 0.4mm. A poke with a needle really doesn't cut it (unless you're Disco Dan's shag -- or so he hopes ).

So, what's the best way to punch a 0.4mm hole into a piece of thin aluminium (paint can if you must know)? Preferably without burrs, and remaining as close to perfectly circular as you can get.

I used to purchase jet drills in .05mm increments from an engineers supplier at the bottom of Nelson St in the central city. Not sure if they are still there, however I am sure that some engineers supplies outfits will have these available.

[Donor]

Ring a model shop, they have stupidly small drill bits for exactly this sort of thing

Errr... what they said!

[Bass]

The commonest way of drilling REALLY small holes uses a spark eroder. You just need some fine enough wire and some money - less than 0.1mm is possible. If you are really keen, PM me. I can refer you to people who can do this kind of stuff

[vifferman]

Wei wei,

I'm playing around with pin-hole cameras and fun stuff like that. Anyway, there's a mathematical equation to what is the best size of pinhole to use for a certain distance from film to hole. For my chosen 8cm focal length, it works out that for the best quality, I really need a hole just a shade under 0.4mm. A poke with a needle really doesn't cut it (unless you're Disco Dan's shag -- or so he hopes ).

So, what's the best way to punch a 0.4mm hole into a piece of thin aluminium (paint can if you must know)? Preferably without burrs, and remaining as close to perfectly circular as you can get.

It's a pin-hole camera - use a pin, or it won't be authentic.

[Usarka]

bloody perverts!

make sure you post the footage

[bungbung]

Dome out a piece of aluminium using a rounded off punch, then sand back the dome using wet and dry until you break through enough to make a hole of the correct size. This will give a hole with nice sharp edges, but easy to handle.

[xwhatsit]

I'm liking these miniature drill bits! I just better purchase about three of them, otherwise *snap* (didn't I do that at one of Justin's workshop nights?).

@bungbung, how do I know when the hole is big enough?

[bungbung]

Print a 0.4mm sized dot on a laser printer, use a 0.5mm mechanical pencil as a guide, 0.3/0.25 drafting pen. Steel rule with 0.5mm grads. What else do you have around home?