I tried a much easier and less expensive experiment. I took a short extension tube and covered the end with tin foil. I pierced a hole in it with an acupuncture needle. It was probably f512 (probably an exaggeration, but it was *small*), and after a rather long exposure (perhaps 30 seconds -- I was indoors) it worked. But I'm after rather a better image than the pinhole (or at least, my pinhole) can produce, so, except for the gratification that I could make such a lens, I discarded it and went back to my takumars. Andrew On 02/07/2011 01:41 PM, Tim Corio wrote: > The body cap is pretty thick. I would expect a lot of reflections > inside the hole causing a foggy look. > > Also, the long (relatively) hole might cause the image to be constrained > to a small circle in the middle of the sensor. Think of drilling a hole > in a wall. Look out through the hole, and move side to side. You'll > only be able to see a tiny bit of the outside. > > Now, drill the same sized hole in a sheet of paper. Move side to side. > Now you can see a much wider area of the outside. > > This is all theory. Please let us know how this works out. I'm curious > to hear more. > > Tim > > On Mon, 2011-02-07 at 21:31 +0000, Christopher Strevens wrote: >> Hi. >> >> >> >> When I made a pinhole camera many years ago, I used copper strip that >> was very thin and placed that over an open box made of cardboard and >> pushed a dressmakerâs pin through the copper in the middle. >> >> >> >> I used printout paper as the sensitive material then used it as a >> paper negative after soaking it in thin machine oil. >> >> >> >> I developed it and fixed it normally. >> >> >> >> Did you know a film may be developed by rubbing with a human thumb? >> >> >> >> As with the box pin hole camera the results are awful. >> >> >> >> I also made photographs using copper plates. I cleaned the copper >> plate with acetone then washed it with hydrochloric acid washed with >> distilled water then dried with acetone. >> >> >> >> It was then exposed to light using a lens and a window. >> >> >> >> I then plated it with silver by putting it in silver nitrate solution. >> It was washed then rinsed with hydrochloric acid and washed again and >> then gold plated with gold chloride solution. >> >> >> >> I then washed it with distilled water. >> >> >> >> All I got was an image of the window in silver and gold. >> >> >> >> Later I took a conventional black and white image and exposed the >> copper plate with an enlarger. >> >> >> >> Eventually I made an image in silver and gold of an unclothed young >> women. >> >> >> >> Then I was attacked. >> >> >> >> Chris >> >> >> >> >> From: owner-photoforum@xxxxxxxxxxxxxxxxxx >> [mailto:owner-photoforum@xxxxxxxxxxxxxxxxxx] On Behalf Of >> mark@xxxxxxxxxxxxxxxxxxxx >> Sent: 07 February 2011 15:07 >> To: List for Photo/Imaging Educators - Professionals - Students >> Subject: RE: making a pinhole >> >> >> >> >> Well I have a drill press and tools so what I was planning to do is >> drill the hole directly into the body cap, but don't know if I can >> find a bit that small after hearing the discussions. Taking it into >> the body cap would give a good clean hole that wouldn't tear up every >> time you threw it into a bag like aluminum foil would. Anything >> paper, ect would be destroyed the first time you tossed it in the >> camera bag. I was hoping for something durable enough that it could >> bounce around, be abused by banging into other stuff in a camera bag, >> and still be totally functional. >> >> >> >> >> >> The solid material being plastic I might be able to heat a needle and >> melt a hole through it. Drilling would give the cleanest hole and I >> suspect that would be key. The thickness of the material also could >> and likely would be an issue I didn't think about. >> >> >> >> >> >> Rather than aluminum foil, if I glued some cloth over a bigger hole, >> fiberglassed over it, painted it flat black, anyone see any problems. >> Would be thicker than foil, but likely much much stronger. It would >> also be a pain to redo if damaged. Oh well >> >> >> -------- Original Message -------- >> Subject: Re: making a pinhole >> From: Tim Corio <tcorio@xxxxxxxxxxxxxxxx> >> Date: Mon, February 07, 2011 8:17 am >> To: List for Photo/Imaging Educators - Professionals - >> Students >> <photoforum@xxxxxxxxxxxxxxxxxx> >> >> I played with this a few years ago using my Canon 5D. I cut a >> large >> hole in a body cap and glued a paper towel tube (painted black >> on the >> inside) to that. Glued a cardboard disk to the end with a >> small >> (quarter inch) hole. I painted the whole outside black in >> several >> layers to fill in a few small light leaks. >> >> Over the hole in the end of the tube I taped a piece of >> aluminum foil. >> In that foil I poked a small hole using a pin. >> >> This gave pretty good results. I could not get a clean hole. >> Small >> defects in the hole scattered light reducing contrast. >> >> Body caps are cheap on eBay and the rest of the material is >> nearly free. >> You can experiment a lot for little cost. >> >> Tim >> >> On Sun, 2011-02-06 at 21:43 -0600, David Dyer-Bennet wrote: >> > On 2011-02-06 16:20, mark@xxxxxxxxxxxxxxxxxxxx wrote: >> > > Came up with an idea. Toyed with the idea of trying some >> pinhole >> > > photography but something always seems to get in the way. >> Came up with >> > > an idea to turn a regular film/digital camera into a >> pinhole using a >> > > body cap. Should work on any 35mm digital ect that would >> accept that >> > > kind of cap, and an extra cap in the bag weighs next to >> nothing and no >> > > bulk or extra stuff to lug around. >> > >> > Would you be shocked to learn they're commercially >> available? I have >> > one for my Nikon bodies. I've done a tiny bit with it on >> digital; I >> > should try it on the D700, which should be a bit better than >> the DX >> > cameras; a bit. >> > >> > > Now I suspect the smaller the hole the better as far as >> sharpness, but >> > > is there a group of sizes that I should try? How much of a >> difference >> > > in hole size should I allow. Granted a body cap isn't >> going to alter >> > > the GDP, but its not like getting another piece of >> cardboard either. Id >> > > be interested to hear thoughts and ideas of those with >> pinhole >> > > experience. >> > >> > For sharpness, there's an optimal hole size (depends on >> distance from >> > sensor), and either bigger or smaller loses you resolution. >> For >> > 35mm-size cameras, going for sharpness is a mugs game, >> though; you don't >> > get sharp pinhole photography from that small a neg. >> > >> > (Lots of easy online resources on hold size.) >> > >> >> > > > -- http://andrewsharpe.com
