But all MTF tests are done using line PAIRS per millimeter. Thus you would convert your x lines per mm into x/2 lp/mm (for comparison purposes) Further, your math is wrong. 2100/25.4 = 82 lines, which translates into 41 lp/mm. Keep in mind that these tests are at full contrast (i.e. Black lines on white background) so comparison to normal 50% MTF is difficult. Michael Sent from my Verizon Wireless BlackBerry -----Original Message----- From: PhotoRoy6@xxxxxxx Date: Mon, 12 May 2008 11:15:25 To:List for Photo/Imaging Educators - Professionals - Students<photoforum@xxxxxxxxxxxxxxxxxx> Subject: Re: Pop Photo Resolution Lines Per ? Pop Photo gives resolution in lines like for the Canon 40D with 28mm-135mm lens it gives 2100 lines from ISO 100 to 1600.... Is this lines per inch? ( I'm assuming it is) 2.54" = cm, .0254" = mm, !" = 39.37 mm per inch, 2100 lines per inch divided by .3937 = 53.34 lines per mm or 2100 lines per inch times .0254 meters = 53.34 lines per mm? (Side not: Only the United States <http://en.wikipedia.org/wiki/United_States> , Liberia <http://en.wikipedia.org/wiki/Liberia> , and Myanmar <http://en.wikipedia.org/wiki/Myanmar> (Burma) still use non metric standards though in the 1970 some road signs had mileage in both miles and kilometer (Research Triangle , NC) but they faded from view. Soda pop and other stuff is sold in liter bottles and metric stuff is now list on many foods) ----------------Wondering what's for Dinner Tonight? Get new twists on family favorites at AOL Food <http://food.aol.com/dinner-tonight?NCID=aolfod00030000000001> .
