Re: [pinhole-discussion] RE: pinhole size
- Original Message - From: Paul Prober pro...@silcom.com The problem experimenting with different pinhole sizes is that unless we are making exposures of resolution targets http://www.???/resources/articles/Young/images/fig5.jpg the results will be always subjective to each viewer, scene, image contrast, whether subject is at close or far from the camera, angle of view, etc, and/or a combination of the above. I have not experimented to find the optimum pinhole size. Chris Patton has, and his conclusion was that the Prober-Wellman Formula is a practical values to use for f/stop to pinhole size for reasonable Circles of Confusion. See http://www.stanford.edu/~cpatton/phcalc3.htm which uses the Prober-Wellman Formula. Patton actually uses a different formula or maybe I should say different constant as all formulas since Lord Rayleigh (1890's) are basically the same. Patton actually has found that bigger pinholes than what most of the rest of us consider optimum, gives him sharper images. OTOH, you have Larry Bullis going the oposite way, that is, he finds that smaller pinholes give him sharper results. Myself, my eyes, rather, are more inclined to align with Larry than with Patton. or http://www.huecandela.com/hue-x/pin-pdf/Prober-%20Wellman.pdf for the white paper study. Also the formula can correct for pinhole to subject distances, for Close-up and Micro pinhole pictures. The Prober-Wellman Formula is exactly what science has been telling us the optimal pinhole formula should be D= SQRT (2.44 * Lambda * F) , the SQRT(1 / M+1 ) factor is a sort of bellows factor as I explained it in a post back in Oct last year: http://www.pairlist.net/mailman/private/pinhole-discussion/2001-October/0042 23.html Guillermo
RE: [pinhole-discussion] re pinhole size
What about using a beer can? Is that to thick of a material? Thanks. Travis -Original Message- From: Paul Prober [mailto:pro...@silcom.com] Sent: Friday, November 01, 2002 12:05 PM To: pinhole-discussion@p at ??? Subject: [pinhole-discussion] re pinhole size Hi, The pinhole size is not the problem. The thickness of the material is. At 70mm or less 0.001 inch thickness and thinner is required to allow for side angle view with minimum roll off. A pinhole with the minimal thickness the expected at 120 degree [+/-60] view angle 1 stop roll off at edge. Lenox Laser has laser pinholes for photography in 0.0005 stainless steel. When designing the PinPLUS Pinhole cameras this became an important requirement for the wide angle cameras design. Lenox Laser drilled pinhole of 250 microns [0.010 inches] in 0.0005 stainless steel meet the requirements for 100 degree diagonally view angle of the PinPLUS 64mm. Paul Prober ___ Post to the list as PLAIN TEXT only - no HTML Pinhole-Discussion mailing list Pinhole-Discussion@p at ??? unsubscribe or change your account at http://www.???/discussion/
[pinhole-discussion] re pinhole size
Hi, The pinhole size is not the problem. The thickness of the material is. At 70mm or less 0.001 inch thickness and thinner is required to allow for side angle view with minimum roll off. A pinhole with the minimal thickness the expected at 120 degree [+/-60] view angle 1 stop roll off at edge. Lenox Laser has laser pinholes for photography in 0.0005 stainless steel. When designing the PinPLUS Pinhole cameras this became an important requirement for the wide angle cameras design. Lenox Laser drilled pinhole of 250 microns [0.010 inches] in 0.0005 stainless steel meet the requirements for 100 degree diagonally view angle of the PinPLUS 64mm. Paul Prober
Re: [pinhole-discussion] Re: Pinhole-size for 5x7 format
--- candy/jules popps...@wccta.net wrote: Can you guys offer some info on making a pinhole for a 5x7 camera. I would like to have about 135 mm. I have read some info and it suggested a #10 needle, but wow is that incredibly small. Maybe drilling would be better. Thanks for any assistance with pointing me in the right direction. Ignore this if the first e-mail makes it through. Thanks again. Jules Jules - If you go to the Pinhole FAQ on my site, you will get a full description of how to make a pinhole. Also, there is a chart that will give you sizes for the different focal lengths you might need. Cheers - george = Handmade Photographic Images http://members.home.net/hmpi/ __ Do You Yahoo!? NEW from Yahoo! GeoCities - quick and easy web site hosting, just $8.95/month. http://geocities.yahoo.com/ps/info1
Re: [pinhole-discussion] Re: Pinhole-size for 5x7 format
Can you guys offer some info on making a pinhole for a 5x7 camera. I would like to have about 135 mm. I have read some info and it suggested a #10 needle, but wow is that incredibly small. Maybe drilling would be better. Thanks for any assistance with pointing me in the right direction. Ignore this if the first e-mail makes it through. Thanks again. Jules - Original Message - From: rust...@aol.com To: pinhole-discussion@p at ??? Sent: Sunday, October 07, 2001 1:18 PM Subject: [pinhole-discussion] Re: Pinhole-Discussion digest, Vol 1 #464 - 10 msgs I have another suggestion for the subject line (forgive me if this has already been suggested and i overlooked it) Could the subject line be in BOLD TYPE? I often scroll down the digest list looking for certain threads of the discussion and it would be easier if the subject line was easier to pick out. Just a thought Rusty ___ Pinhole-Discussion mailing list Pinhole-Discussion@p at ??? unsubscribe or change your account at http://www.???/discussion/
