Karl, Then does it follow from here that 1-The ONLY reason we loose resolution when we blow up an image on the film is because of the grain and other impurities of the film itself, and 2-The resolution power of the optical system (lens) is infinite. izzet > -----Original Message----- > From: owner-photoforum@listserver.isc.rit.edu > [mailto:owner-photoforum@listserver.isc.rit.edu] On Behalf Of > Karl Shah-Jenner > Sent: Saturday, September 07, 2002 12:00 PM > To: List for Photo/Imaging Educators - Professionals - Students > Subject: Re: Two basic and dumb questions about lenses > > > > From: "Izzet" > > Assume I have a 35 mm. SLR with a 28 mm. lens on it. I am looking > > though the viewfinder to the subject. Then I change the > lens to a 300 > > mm, and look at the same subject from the same distance. Now the > > subject is filling more of my view and also seems magnified. > > > > 1- Is the reason for that magnification ONLY the decreased > > field-of-view? > > yes :-) > > > > 2- If this is so, do I get the same image if I use a > > a)300 mm. tele and print full-frame to an 8*10 card, > > I'm assuming you mean an 8x10 print, the answer is yes.. > > > > b)100 mm. tele and print full-frame to a 24*30 (if it > exists) and then > > crop to an 8*10? > > yes. > > > If you do not change your perspective, that is to say that > you do not change your position, then the relationships > between all that you see in your viewfinder remains > unaltered. you just see more or less of the scene with each > different focal length lens. > > Look at it one other way, if you used a 50mm wide-angle lens > on an 4x5 camera and then cropped the center out of the image > to make a 35mm frame you'd get a picture the same as if you'd > used a 50mm lens on a 35mm camera - it would be a 'normal' > lens for the 35mm format but a wide angle for the 4x5 :-) > > > karl > > --- > Incoming mail is certified Virus Free. > Checked by AVG anti-virus system (http://www.grisoft.com). > Version: 6.0.385 / Virus Database: 217 - Release Date: 04.09.2002 > >
