Archived posting to the Leica Users Group, 1998/04/30
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Eric Welch wrote: > Your exepriment has to do with angle of view, not magnification. Let's cut to the chase. Magnification is not a term used in association with camera lenses (apart from macro lenses). The reason is simple. Camera lenses do not magnify anything. All they do is record a certain angle of view on a particular area of film. That's it. Period. Unless you are into macro, everything you record on the film is probably 1/1000 magnification. A human being is reduced to the size of a few mm. That's all that can be said about magnification in regards to photography. There is no possible way you can get to the conclusion that a 50mm lens has the same magnification as the human eye, whether either one is or isn't cropped, except if you bring into the equation the particular properties of the camera's viewfinder. (A red herring you tried to throw in there). That's irrelevant as far as the resulting photo is concerned. > Yep, the fact that our eyes only see a few, at best, letters perfectly is > irrelevant. It's the MAGNIFICATION! If this was such a fundamental principle, there would be some experiment I could perform or some calculation that could be made that would show it to be so. The reason there isn't is simple. LENSES DON'T MAGNIFY. All they do is crop a particular angle of view out of the surroundings, and place it on a certain size film. On the other hand, once you make a print from the film, enlarge it to a certain size, then view it from a certain distance, THEN you can say something about the magnification. But then it is totally dependant on the size of the enlargment and the distance it is viewed from. A print from a 14mm or 2000mm lens can have the same magnification as in real life if printed the appropriate size and viewed at the appropriate distance. >>It is impossible to say that a 43mm lens gives 1x or .5x or 2x or >>any other number of magnification. Tell us how a scientist might >>determine what length lens corresponds to the human eye? > >Now, why would that be? Every person in the world who has normal vision >sees things pretty much the same way in terms of magnification. Presumably, but no-one sees the same way as a camera. So comparing them is fruitless. - -- Chris Bitmead http://www.ans.com.au/~chrisb mailto:chrisb@ans.com.au