Yes, there is a pinhole diameter that will give best sharpness for each distance from pinhole to film. The simplest version of the formula is (distance to film in inches)(55) equals the square of the optimal diameter in thousandths of an inch. In your case (1.12 inches)(55) equals 68.99, the square root of which is 7.84 thousandths, or 0.00784 inches.----- Original Message ----- From: "Zami Schwartzman" <zami...@netvision.net.il> To: <pinhole-discussion@p at ???????> Sent: Saturday, October 12, 2002 2:28 AM Subject: [pinhole-discussion] 35 mm pinhole camera
> Anyone has tried converting a 35 mm camera to pinhole ? > > I have modified an old Pentax Spotmatics Reflex camera , the idea was that > using a 35 mm format will make it easier to experiment with various types of > films . film drive , sutter timing , tripod attachement and release cable > are already there and any local photo shop will process the films for me . > I turned a "lens" boby on my lath that allows the metal foil be located 28 > mm from the film . > I discovered that with this camera I can flip the mirror up permanently > without disabling other camera functions ( except for the viewfinder that > obviously is shut off ) > > I use 0.02 mm copper foil .The pinhole was made under a x70 stereo > microscope by using a very sharp pin ( honed under the microscope ) on hard > back surface . > the buurs on the oposit side had to be very carefuly treated with no. 400 > sandpaper to get a perfect hole . Although not a sraight forward job , I can > get perfect holes as small as 0.05 mm diameter ( I have scale on the > microscope ) . there is no chance to get any smaller with manual pin > puncturing tecniques . > > I experimented with a 0.1 mm hole , got some good close up pictures well > exposed with Kodak gold 400 ASA( using f: 120 on the light meter ) but the > results are quite " out of focus " on 10x15 prints . > > I wander if going further to a 0.05 hole will worth the panelty in the f > number . > Is there an optimun hole size for best sharpness ? or is it the smaller > the better . > > I hear that some people are converting plastic 35 mm cameras , I wander > what holes they use and how sharp is the resultant image they get . > > Zami > > > > > -----Original Message----- > From: pinhole-discussion-admin@p at ??????? > [mailto:pinhole-discussion-admin@p at ???????]On Behalf Of DAVID WALTERS > Sent: Friday, October 11, 2002 11:29 AM > To: pinhole-discussion@p at ??????? > Subject: [pinhole-discussion] Re: New to the list and saying "hello".... > > > Evening, I apologize for the lag time on answering but > I had a brief episode of file overload while trying to > upload some pics (Sorry and thanks, Gregg). I have a > pinhole from my last roll posted at > "http://photos.yahoo.com/bc/wal...@prodigy.net/lst?.dir=/Photo+art&.src=ph&;. > order=&.view=t&.done=http%3a//photos.yahoo.com/" > ("badge"), along with some other pieces of mine. The > body cap is on my Canon EOS, I measured the distance > at 49 mm and I'm using a laser drilled opening of > .0102", this gives an f/stop of 163, I reckon. Using > the bulb setting has given me fairly good results with > Kodak film, although it seems to be able to meter > through the pinhole. The Polaroid pinholes are from a > Polaroid 210 with a hand drilled pinhole, I had such a > bad rolloff because of reciprocity that I have stuck > with B/W since. I might go back to color with the 210 > and stick to extreme sun in the future, we'll see. > Thanks for the welcome, David Walters > > _______________________________________________ > 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/ > > > > _______________________________________________ > 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/ >
