Archived posting to the Leica Users Group, 2008/08/30
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]On Aug 30, 2008, at 6:57 AM, Leonard Taupier wrote: > Peter is absolutely correct in his assessment of the two lenses. > > Resolution tests are normally made at the lens infinity setting > using sophisticated optical measuring equipment. I have tested both > of these lenses using test charts at the required distance of 8' 3" > from lens to chart for a 50mm lens. I find that when using an M8 for > the test that the resolution is limited by the M8 resolution and not > the lens. At the 8' 3" distance I find the resolution of the two > lenses from f5.6 to f11 to be the same. The Summilux at f1.4 is very > fine but from f2 to f4 the DR lens gives me higher resolution. that's amazing... > This is caused by a focus shift and back focus at those openings, > very similar to the shift of the Noctilux, but to a lesser extent. > This is probably not a problem at longer distances and especially at > infinity. I also measure higher resolution when testing with low > grain, high sharpness film and developers using an M7 or MP body. I > can never measure resolution above 88 lpmm with the M8 but measure > 100 lpmm with film with the same lens at the same openings. The > focus shift is also not so obvious. But even though the resolution > of the DR and Summilux are the same, the Summilux has higher > contrast and photos taken with it appear sharper. > > As a side note, the Noctilux is just as sharp as the Summilux in the > f5.6 to f11 openings. Some of the Luggers know this and take > advantage of it and treat the Noctilux as a normal lens. > > Note: This is what a retired engineer enjoys doing on rainy days > when he's not out taking pictures of birds, flowers or landscapes. This is helpful and very interesting Len. I rarely test lenses this way. But just using the lenses to take photos gives me the same impressions, and though I may be a heretic, but I don't care about the ASPH's technical details, and bench tests...I often find its look analytic and brittle... I like very much the look of the DR, so it's interesting that measurements at some f stops show it to have an even higher resolution... the difference at least in part comes down to the much lower contrast characteristics, which you can season to taste. Steve > > > Len > > > On Aug 30, 2008, at 1:58 AM, Peter Klein wrote: > >> Lee: The DR has very high resolution, and also moderate contrast. >> The latter might be a good thing for digital. Really bright >> highlights tend to bleed slightly into their darker surroundings, >> which sounds like a defect but actually looks very nice in practice. >> >> This is different from the Summilux ASPH, which is a modern lens >> with biting sharpness--high contrast as well as resolution. >> Completely different personality. My guess is that you might >> prefer it over the DR for aerial photography. >> >> My take is that one doesn't use a DR for its resolution so much as >> one uses it for its look. >> >> The DR was my favorite outdoor lens with film, and I intend to use >> mine on my M8 when it comes back from its "operation" at DAG. >> >> Hope this is useful. >> >> --Peter >> >> >> _______________________________________________ >> Leica Users Group. >> See http://leica-users.org/mailman/listinfo/lug for more information > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information