masjah Posted August 12, 2009 Share #1 Posted August 12, 2009 Advertisement (gone after registration) Can anyone tell me where the distance is measured from please? Is it the film plane, the lens mount, or the lens front? I guess it's only really significant at close distances, but I would like to know! Link to post Share on other sites More sharing options...
Advertisement Posted August 12, 2009 Posted August 12, 2009 Hi masjah, Take a look here R lens distance scale?. I'm sure you'll find what you were looking for!
SJP Posted August 12, 2009 Share #2 Posted August 12, 2009 The focus distance on a lens is defined as the sum of the object and image distance, so from the sensor/negative to the object. Via the lens equation which is good enough for this purpose 1/f = 1/O + 1/B and the focus on the lens scale is O + B. (O = Object, B= Bild = Image, f = focal length) Link to post Share on other sites More sharing options...
masjah Posted August 12, 2009 Author Share #3 Posted August 12, 2009 The focus distance on a lens is defined as the sum of the object and image distance, so from the sensor/negative to the object. Via the lens equation which is good enough for this purpose 1/f = 1/O + 1/B and the focus on the lens scale is O + B. (O = Object, B= Bild = Image, f = focal length) Stephen Many thanks for the clarification. So I'll simply measure tot the film plane ( O + . Link to post Share on other sites More sharing options...
ismon Posted August 12, 2009 Share #4 Posted August 12, 2009 Focus is measured from the film plane. On some R-cameras, there is a mark on the top plate, consisting of a small circle with a line through the middle. That indicates the film plane. On earlier Leicaflexes (and R8/9), just judge by the rear edge of the shoe. Link to post Share on other sites More sharing options...
masjah Posted August 12, 2009 Author Share #5 Posted August 12, 2009 Focus is measured from the film plane. On some R-cameras, there is a mark on the top plate, consisting of a small circle with a line through the middle. That indicates the film plane. On earlier Leicaflexes (and R8/9), just judge by the rear edge of the shoe. Thanks ismon - since I have an R8 abd an R9, that was my next question. Link to post Share on other sites More sharing options...
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