Archived posting to the Leica Users Group, 2012/07/10

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]

Subject: [Leica] Daguerreotype Plate Sizes at 72 dpi
From: mark at rabinergroup.com (Mark Rabiner)
Date: Tue, 10 Jul 2012 17:52:41 -0400

A quick search and it seems to really be 4.25 x 5.5 inches coming from all
directions on the list.

- - from my iRabs.
Mark Rabiner
http://gallery.leica-users.org/v/lugalrabs/


> From: John McMaster <john at mcmaster.co.nz>
> Reply-To: Leica Users Group <lug at leica-users.org>
> Date: Tue, 10 Jul 2012 21:30:24 +0000
> To: Leica Users Group <lug at leica-users.org>
> Subject: Re: [Leica] Daguerreotype Plate Sizes at 72 dpi
> 
> Isn't half plate 4.25" x 6.5" (rather than 5.5")?
> 
> Ah, 6.5" for glass plates and sheet film but 5.5" for tintypes -
> http://en.wikipedia.org/wiki/Tintype
> 
> Learnt something already today :-)
> 
> john
> ________________________________________
> 
> 
> Here are the Daguerreotype Plate sizes worked into pixels from the I think
> original Cm sizes
> Whole Plate:    6.5 x 8.5 inches    (16.5 x 21.5 cm)  462 x 602 pixels
> Half Plate:    4.25 x 5.5 inches   (11 x 14 cm) 308 x 392
> Quarter Plate:    3.25 x 4.25 inches    (8 x 11 cm) 224 x 308
> Sixth Plate:    2.75 x 3.25 inches    (7 x 8 cm) 196 x 224
> Ninth Plate:    2 x 2.5 inches    (5 x 6 cm) 140 x 168
> Sixteenth Plate:    1.375 x 1.625 inches    (3.5 x 4 cm)   98 x 112
> 
> Its the cm size times 28
> 
> Introducing the numbers 28 and 72 to them certainly does not turn them into
> any warm and fuzzy numbers.
> 
> Here was the conversions from inches.
> 
> 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
> 
> Its like translating the bible from Greek instead of Hebrew. Or whatever it
> was originally written in.
> 
> 
> 
> - - 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 17:11:27 -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
>> 
>> Not 32 but 28
>> Conversion table
>> DPI
>> (dot/in)    dpcm (dot/cm)    Pitch (?m/dot)
>> 72             28                              350
>> 
>> " There are some ongoing efforts to abandon DPI in favour of metrication,
>> giving the inter-dot spacing in dots per centimetre (dpcm) or micrometres
>> (?m).[5][6] A resolution of 72 DPI for example equals a resolution of 
>> about
>> 28
>> dpcm or an inter-dot spacing of about 350 ?m."
>> 
>> 
>> - - 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.
> 
> 
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information




Replies: Reply from mark at rabinergroup.com (Mark Rabiner) ([Leica] Daguerreotype Plate Sizes at 72 dpi)
In reply to: Message from john at mcmaster.co.nz (John McMaster) ([Leica] Daguerreotype Plate Sizes at 72 dpi)