Thanks for the timely thumb rule, Pat. I'm talking on the physics of the eye and on sight-error corrections today in physics lecture. I'll present this with my material.
Jim Pat Naughtin wrote: > > Dear Terry and All, > > This thought from my 'Rules of Thumb' might be useful. > > Reading: � Reading is easy for most people if the letters are 5 millimetres > high at a distance of 500 millimetres; from this we get a ratio of 1:100, > and this will work on any scale. If you are planning a billboard 40 m from a > country road then the letters should be 400 millimetres high (40 m � 100 = > 40 000 mm � 100 = 400 mm). Similarly, if you are designing a conference > poster to be read from 2 m the letters should be a minimum of 20 millimetres > high (2 000 mm � 100 = 20 mm). -- Metric Methods(SM) "Don't be late to metricate!" James R. Frysinger, CAMS http://www.metricmethods.com/ 10 Captiva Row e-mail: [EMAIL PROTECTED] Charleston, SC 29407 phone/FAX: 843.225.6789
