Archived posting to the Leica Users Group, 2020/12/18
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]HAHAHAHAHAHAHA ric > On Dec 18, 2020, at 5:26 PM, Howard Ritter via LUG <lug at > leica-users.org> wrote: > > The exposure was on photo paper, so ISO maybe 0.1? The diameter of a beer > can is, say, 65 mm. The pinhole, I?m guessing, was ~0.1mm so, f/650 @ ISO > 0.1. Rule of thumb is daylit scenes take 1/ISO @ f/16. That would be 10s @ > f/16. 650/16 = ~40 and 40^2 = 1600. So daylight exposure would be 10s x > 1600, or about 5 hours. > > Then you gotta figure how many equivalent hours of full sunlight there are > in an average Hertfordshire day over the course of a year, figuring in > clouds, low sun angles, etc. Three, maybe? So 8000-9000 h of exposure. > Just a trifle overexposed. > > Of course, even the direct imaging of the Sun on the paper didn?t blast it > out, so maybe the pinhole was more like 0.01 mm, making the proper > exposure 500h. And then there?s monumental reciprocity failure? > > > ?howard > >> On Dec18, 2020, at 1653, Douglas Barry <imra at iol.ie> wrote: >> >> Incredible. We know the shutter speed, and should be told the film type >> and aperture... >> >> Douglas >> >> On 18/12/2020 14:19, Howard Ritter via LUG wrote: >>> Some seek world records. Others have world records thrust upon them? >>> >>> https://www.herts.ac.uk/about-us/media-centre/news/2020/longest-known-exposure-photograph-ever-captured-using-a-beer-can >>> >>> <https://www.herts.ac.uk/about-us/media-centre/news/2020/longest-known-exposure-photograph-ever-captured-using-a-beer-can> >>> >>> >>> ?howard >>> >>> _______________________________________________ >>> Leica Users Group. >>> See http://leica-users.org/mailman/listinfo/lug for more information >> >> >> _______________________________________________ >> Leica Users Group. >> See http://leica-users.org/mailman/listinfo/lug for more information > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information