Archived posting to the Leica Users Group, 1999/09/27
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]In a message dated 9/27/99 3:06:44 PM Eastern Daylight Time, raimo.korhonen@pp2.inet.fi writes: << Hi all! Modern Photography (June 1985) that the view area compared to film is 86% vertically and 86% horizontally and 0.15mm/0.15mm parallax respectively. Popular Photography (July 85) has a picture that shows that the viewfinder image with 50mm lens is very slightly bigger than the on-film image - more than 100% - but no percentages stated. Who´s correct? All the best! Raimo >> According to Leica's own literature the framelines in the M Leicas are set to fixed field size for each lens at its closest focusing distance, less an amount equivalent to that which is cropped by a standard slide mount. Therefore at varying distances on out to infinity the framelines show less and less of the actual on-film image. Using a ground glass at the film plane I have determined that (for an M6 .72) at infinity the on-film image with a 90mm lens is almost exactly that shown by the 75mm frameline; the image from the 75mm lens at infinity is quite close to the 50mm frameline; and the infinity image of a 50mm lens can be roughly estimated by the eyepiece mask when sighted from one inch. For the shorter focal lengths the discrepancy is there but less significant (this stands to reason since there is less loss of coverage with a wide angle lens as it is focused closer, due to less extension required). What the divergence of the M framelines is from 100% is impossible (ok, someone with a PhD in mathematics will disagree) to calculate, because it is different for every focal length and every distance, unlike an SLR whose finder view changes proportionately to the focal length and extension of the lens in use. DT