[pinhole-discussion] yay!
i'm finished making my new camera... http://www.rahji.com/images/wooden_bottom.jpg http://www.rahji.com/images/wooden_front.jpg http://www.rahji.com/images/wooden_side.jpg it's made of poplar. there's a wooden frame inside to hold the film/paper in and also create a light trap. i machined all of the metal parts (except for the little knob-key things) out of aluminum. i sanded a finger tip off, blackened a fingernail on a belt sander, and burned two fingers on a hot screw that i was grinding with a cutoff wheel - this is how my last few months have been going .. everything i produce is measured in the number of injuries sustained in the process. :) rob
Re: [pinhole-discussion] Pinholin' and hard boiled eggs
To answer the original question, the air sac is at the big end. - John Jim Kosinski wrote: Guy - c'est superlatif! but where the heck is the bottom of an egg? Jim K Many thanks, Jim Kosinski From: Guy Glorieux guy.glori...@sympatico.ca I pull out two eggs from the fridge and a neddle from the drawer. I pierce a small pinhole at the bottom of the eggs and put them in the water to cook to hard. Gisèle looks at me: - I've seen you do that so many times but never asked. Why do you do that to the eggs? Me: - It's because there's a small air bag at the bottom of the eggs. When the temperature of the water rises to boiling, usually the pressure increases inside the eggs and they break. If you pierce a pinhole in the air bag, the pressure can rise, the air will come out through the pinhole and the eggs won't crack. Gisèle: - You sure know how to get pinholin' in every aspects of your life, don't you... Me: - Told you so... -:)) Try it! It really works fine. Pinholin' and hard boiled eggs. Chef Guy
Re: [pinhole-discussion] Pinholin' and hard boiled eggs (very OT)
I wondered if anyone was going to call me on this - I don't know! -And I grew up around chickens! - John ragowaring wrote: Answer to this would end many hours of discussing this with my wife. I think it is the big (or blunt) end that comes out first Alexis on 5/5/02 4:31 am, John Edwards at e...@mindspring.com wrote: That would be the end that comes out of the hen last. ;-) - JE Jim Kosinski wrote: Guy - c'est superlatif! but where the heck is the bottom of an egg? Jim K Does anyone know which end of the egg comes out of the hen first? Is it the blunt end or the pointed end?
Re: [pinhole-discussion] Optimal pinhole size question - theoretical practical
- Original Message - From: Tom Harvey harv...@aracnet.com It's the very, very that I wonder about. I believe that Zernike Au has said that he used the smaller aperture because tested out sharper. Aside from lengthening exposure times, would using small size pinholes on cameras with focal lengths of twice the optimal focal length be any less sharp? Tom, All optimum pinhole formulas, starting with Lord Rayleigh's (1891) to the most modern one, like the one in M.Young's article foound at PV site, can be expressed as: Diameter = SQRT( K * F * Lambda ) That constant K has taken many values, some based on analitical reasons, some based on experimental reasons. You implicitly mentioned 2 values, the one in Renner's book, which BTW is congruent with modern formulations and Zernike's, which you mention to have read was found experimentally and gives way smaller diameters than the modern scientific formulation. I know of another experimental value, that found by C.Patton, which oddly enough, gives larger diameters. So there you have it, science says something and 2 pinholers have found experimentally that a larger hole produces better resolution (Patton) and the other (Zernike) than a smaller hole produces better results. I have to mention that Patton's value doesn't deviate drastically away from the scientific formulation as Zernike's does. Since pinhole is not about sharpness, use any pinhole size for a particular distance pinhole-film, but I suggest you use what I call the scientific formulation as the starting point from which deviate. Guillermo
[pinhole-discussion] Image #376-Photo from the top of the world.
Hi all, I must say that as each day goes by I get more and more impressed with the WPPD. Some one took a photo at the North Pole! Serge, thanks. Now all we need to get is a photo from the South Pole. Maybe next Year? James
[pinhole-discussion] Pinhole Photography Exhibition
Photographs by Renée Creager O’Brien will be on exhibition during the month of June 2002 at Cool Beans, S. Western Ave. Queensbury, NY. The photographs in this exhibition were made using 120 b w negative film loaded in a 1924 Brownie camera converted into a pinhole (lensless) camera. In a chemical darkroom, positives were made on archival papers then hand-colored with Marshall’s Photo Oils. Each image is a unique print. The photographic selections represent recent work that examines landscape in the broadest sense of the term. It is a contemporary landscape veiled in timeless human experiences such as work, leisure daily ritual. Renée Creager O’Brien lives in Hadley and teaches photography at Adirondack Community College. Attached: Beetle on Broadway, Saratoga Springs 6.01, 1.02 6” x 8.5” hand-colored pinhole photograph inline: Beetle on Broadway
