I got 1.4 as the distance ratio by comparing triangles with h the same and thus: h/d1=ih1/f1, h/d2=ih2/f2 so (h/d1)/(h/d2)=(ih1/f1)/(ih2/f2) >d2/d1=(ih1/f1)/(ih2/f2)=(280/150)/(211/280)=(280/150)*(280/211)=280*280/150 *211=2.477 So I made a mistake. The answer I now get is 2.48 Chris, http://www.chrisspages.co.uk In Memory of Maia, a sad, sad story. -----Original Message----- From: Chris [mailto:nimbo@xxxxxxxxxxxxxx] Sent: 25 August 2004 10:05 To: photoforum@xxxxxxxxxxxxxxxxxxxxxx Subject: RE: A photo exercise for students at RIT - FYI Hi, I make the focal length of the rh lens as 280mm and the increased distance factor as 1.4 Chris, http://www.chrisspages.co.uk In Memory of Maia, a sad, sad story. -----Original Message----- From: owner-photoforum@xxxxxxxxxxxxxxxxxxxxxx [mailto:owner-photoforum@xxxxxxxxxxxxxxxxxxxxxx]On Behalf Of ADavidhazy Sent: 12 August 2004 03:15 To: List for Photo/Imaging Educators - Professionals - Students Cc: andpph@xxxxxxxxxxxxxxx Subject: A photo exercise for students at RIT - FYI On the web I have posted an image and associated instructions on what to do with it. It is part of a short workshop on perspective which in turn is part of a year-long course (made up of about 25 different topics ranging from basic optics to densitometry and variability, color theory, plotting, film speed determination, resolution, etc.) designed to raise awareness and explore photographic topics that most other courses don't touch on or if they do they cover them in a different maybe more "practical" way. This particular subset of a 2 hour workshop is located on the web here: http://www.rit.edu/~andpph/photofile-misc/perspective.jpg
