david_clark4 Posted June 4, 2006 Share Posted June 4, 2006 When they are describing lens performance, and they say that the lens performs best at medium range and mid-apertures - what I want to know is just what is the distance of the medium range? Is it halfway between 50 ft. and a yard on a 50mm lens scale, or is it half way between you and horizon? And what is considered the near and far distance of their mid range? Thanks. Link to comment Share on other sites More sharing options...
bobatkins Posted June 4, 2006 Share Posted June 4, 2006 "Medium range" is usually around 30x the focal length. Normally there's not much difference between that and performance at infinity. Lenses which focus by simple linear extension usually perform less well when the focus distance drops below maybe 10x their focal length. Link to comment Share on other sites More sharing options...
subhash_tiwari Posted June 4, 2006 Share Posted June 4, 2006 Really ? In that case a lens with a focal length of 50mm (2 inches) will be best at (2X30) 60", and a 300 mm lens at 30 ft. And the wide angles- a 28mm best at about 2 1/2 ft. ?- all these distances seem awfully short... Link to comment Share on other sites More sharing options...
sergio_ortega7 Posted June 4, 2006 Share Posted June 4, 2006 Bob, how did you determine that the "medium range" is "30x the focal length"? Where did you see this? Link to comment Share on other sites More sharing options...
john_graham3 Posted June 4, 2006 Share Posted June 4, 2006 Hey, don't question the guy, he's an expert with a website and everything :*) Link to comment Share on other sites More sharing options...
frank uhlig Posted June 4, 2006 Share Posted June 4, 2006 All you doubters above need to realize that at any other distance (closer or further away) lenses will give you around 95+% of their best performance, unless you go to true macro with a curved field lens. So, it is not the lens, since it is quite near optimal on most of its range, but our own faulty technique. Food for thought, in my book. ... Link to comment Share on other sites More sharing options...
dead_metaphor Posted June 4, 2006 Share Posted June 4, 2006 How ever far away the subject is. Link to comment Share on other sites More sharing options...
vivek iyer Posted June 4, 2006 Share Posted June 4, 2006 I could not understand the first two sentences of your post, Frank. Would you clarify? TIA. Link to comment Share on other sites More sharing options...
graham_line Posted June 4, 2006 Share Posted June 4, 2006 Mid-range wouldd be the part that's neither very close, nor really far away. :-) The fat part of the distance scale that isn't up against the stops. Mid-aperture for most 35mm format lenses is somewhere around f/5.6 to f/11, where the lens is stopped down enough to hit maximum resolution and the effects of diffraction haven't set in. People who realise they shoot most of their photos at mid-range and mid-aperture can save themselves a lot of money by not buying 'luxes. Link to comment Share on other sites More sharing options...
eliot_rosen1 Posted June 5, 2006 Share Posted June 5, 2006 As I understand it, most Leica M lenses are optimized for long distances relative to their focal lengths (except the 90/4 Macro-Elmar-M). The close-up performance (less than 3 meters and especially less than 1 meter) will not be as good as that at longer distances, and it is better to stop the lens down if possible, for close distances if maximal sharpness is required. Even the MEM will perform better at medium-long distances than at short distances. Also bear in mind that it is harder to correct wide aperture lenses (F/1.4) for excellent close-up performance than F/2 or F/2.8 lenses. Link to comment Share on other sites More sharing options...
david_clark4 Posted June 5, 2006 Author Share Posted June 5, 2006 It would seem then that the best way to focus for optimal resolution and contrast would be to dial the lens to a hyperfocual distance, say put the infinity mark on f5.6 or f8 on the scale for a mid range, and use the camera like that. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now