On Fri, 7 Dec 2001, Kent Gittings wrote: > I think you are missing some info. The chip in the Dimage 7 is the same one > that is in the Nikon D-1x which is 5.24 MP and 23.7mm x 15.6mm. It's a > matter of semantics. > When you see a CCD array listed as 2/3 inch it doesn't refer to the actual > size but to the ratio when compared to a 35mm frame.
This is not true. Dimage 7's CCD is *much* smaller than that of Nikon D1x. The focal length of the lens is the big clue (more on this later). 2/3" is a standard specifications used in CCD image sensor - and it has nothing to do with 35mm frame. The image circle diameter of a 2/3" or 2/3 type CCD sensor is actually only 11mm: http://www.navitar.com/zoom/cctv_how.htm Please note that the horizontal and verticle measurement in the table of the above web page is not correct; as it was calculated for 4:3 TV image CCD. For 3:2 photo CCD, the 2/3" sensor should roughly measures 9.15mm x 6.10mm which is approx 4x lens ratio. And this agrees with the specs: Dimage 7 lens has focal length 7.2-50.8 (35mm equilvalent of 28-200). > lens ratio. The chips that say 1/1.8 inch (Dimage 5 is an example) are > physically approximately 20mm x 13.3mm. No, more like 7.40mm x 4.93mm; thus yielding a 35mm equilvalent of 35-250 focal length despite using the same 7.2-50.8 lens as Dimage 7. -- --Lawrence Kwan--SMS Info Service/Ringtone Convertor--PGP:finger/www-- [EMAIL PROTECTED] http://www.vex.net/~lawrence/ -Key ID:0x6D23F3C4-- - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
