Archived posting to the Leica Users Group, 2003/12/16
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Jay-- Thanks for the explanation. I knew that if the focal-length equivalencies given by Leica were correct, the sensor had to be 1/4 of the linear dimensions of the 35mm frame, or about 9mm x 6mm. The Digilux uses the 4:3 ratio apparently, which I think makes more sense than the usual 35mm 3:2. After all, who prints 8 x 12 enlargements? Preposterous that Leica should be using such arbitrary, inexact, and nonquantitative nomenclature in the 21st Century! Anyone have any inklings of price or date? - --howard - ----- Original Message ----- From: "Jay Burleson" <jayburleson@earthlink.net> To: <leica-users@mejac.palo-alto.ca.us> Sent: Monday, December 15, 2003 11:32 PM Subject: RE: [Leica] Digilux 2 > Howard, > A 2/3 sensor is 8.8 x 6.6mm, with a diagonal of 11mm. > > (below is copied from > http://www.dpreview.com/news/0210/02100402sensorsizes.asp) > > "We regularly receive emails from readers confused as to the actual size of > sensor used in digital cameras. Sensors (CCD / CMOS) are often refered to > with an imperial fraction designation such as 1/1.8" or 2/3", this > measurement actually originates back in the 1950's and the time of Vidicon > tubes. Those who find the specification sheets for these sensors are then > even more confused about the relationship between the fraction and the > actual diagonal size of the sensor. Inside you'll find an explanation and a > table of common sensor sizes. We'll be adding this information to our > glossary for future reference. > It all started way back when... > The 'Type' designation given to toady's CCD sensors is that it harks back to > a set of standard sizes given to TV camera tubes in the 50's. These sizes > were typically 1/2", 2/3" etc. The size designation does not define the > diagonal of the sensor area but rather the outer diameter of the long glass > envelope of the tube. Engineers soon discovered that for various reasons the > usable area of this imaging plane was approximately two thirds of the > designated size. This designation has clearly stuck (although it should have > been thrown out long ago). There appears to be no specific mathematical > relationship between the diameter of the imaging circle and the sensor size, > although it is always roughly two thirds." > > Read more at the link above. > > Jay Burleson > “Every normal man must be tempted at times to spit on his hands, hoist the > black flag, and begin slitting throats.” > H. L. Mencken > > > --- > Outgoing mail is certified Virus Free. > Checked by AVG anti-virus system (http://www.grisoft.com). > Version: 6.0.551 / Virus Database: 343 - Release Date: 12/11/03 > > > -- > To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html