Archived posting to the Leica Users Group, 2012/07/10
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]It would appear: Conversion table DPI (dot/in) dpcm (dot/cm) Pitch (?m/dot) 72 28 350 That the magic number is 32 for Cm's - - from my iRabs. Mark Rabiner http://gallery.leica-users.org/v/lugalrabs/ > From: Mark William Rabiner <mark at rabinergroup.com> > Date: Tue, 10 Jul 2012 17:03:44 -0400 > To: Leica Users Group <lug at leica-users.org> > Conversation: [Leica] Daguerreotype Plate Sizes at 72 dpi > Subject: Re: [Leica] Daguerreotype Plate Sizes at 72 dpi > > Daguerreotype Plate Sizes were based on the avaible size of plate glass > used > in windows. Well the full size would have been I don't know about the > cutting > down into the quarter and sixteenth plate sizes the logic which was used. > You > often see the list on the internet listed as inches. I've not yet seen them > metric. I think inches was a UK thing from way back was it not also a > French > thing? > > http://en.wikipedia.org/wiki/Daguerreotype > > Ok from this source here > Whole Plate: 6.5 x 8.5 inches (16.5 x 21.5 cm) > Half Plate: 4.25 x 5.5 inches (11 x 14 cm) > Quarter Plate: 3.25 x 4.25 inches (8 x 11 cm) > Sixth Plate: 2.75 x 3.25 inches (7 x 8 cm) > Ninth Plate: 2 x 2.5 inches (5 x 6 cm) > Sixteenth Plate: 1.375 x 1.625 inches (3.5 x 4 cm) > It appears from this list the inche sizes were based on the original CM > sizes > not the other way around. > Perhaps I should redo it with a straight to pixel from CM conversion. > Though I don't know what the math is on that. > Here is the source > http://cwfp.biz/platesizes.php > > > > > - - from my iRabs. > Mark Rabiner > http://gallery.leica-users.org/v/lugalrabs/ > > >> From: Philippe Amard <philippe.amard at sfr.fr> >> Reply-To: Leica Users Group <lug at leica-users.org> >> Date: Tue, 10 Jul 2012 22:52:22 +0200 (CEST) >> To: Leica Users Group <lug at leica-users.org> >> Subject: Re: [Leica] Daguerreotype Plate Sizes at 72 dpi >> >> Are you sure the unit used then was the inch? I'm sure the photos will be >> better if you use cms ;-) Nice idea about the format, unsure about the >> pixel count though. AMiti?s Philippe Tous vos emails en 1 clic avec >> l'application SFR Mail sur iPhone et Android - En savoir >> plus. ======================================== Message du : 10/07/2012 >> 22:04 De : "Mark Rabiner " <mark at rabinergroup.com> A : "Leica Users Group" >> <lug at leica-users.org> Copie ? : Sujet : [Leica] Daguerreotype Plate Sizes at >> 72 dpi Whole plate 6-1/2" x 8-1/2" 468 x 612 pixels Half plate >> 4-1/4" x 5-1/2" 306 x 396 Quarter plate 3-1/4" x 4-1/4" 234 x >> 306 Sixth plate 2-3/4" x 3-1/4" 198 x 234 Ninth plate 2" x >> 2-1/2" 144 x 180 Sixteenth plate 1-3/8" x 1-5/8" 99 x 117 I >> worked the math on these plates sizes into pixels. I plan on working up some >> images at these sizes which perhaps will have some resonance in our photo >> DNA. Sometimes I plan on just entering the inch sizes at whatever >> resolution >> I'm using on the print. As they are a bit small for the screen even. I really >> don't know. Maybe I'll find myself using these all the time. Or hardly ever. >> But It was fun doing it. - - from my iRabs. Mark >> Rabiner http://gallery.leica-users.org/v/lugalrabs/ ______________________>> _ >> ________________________ 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