Archived posting to the Leica Users Group, 1999/09/29
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]From: Alexey Merz <alexey@webcom.com> Sent: Wednesday, September 29, 1999 05:43 Subject: [Leica] (long) Anthony: no apparent difference between lenses > My point is that your test is not a valid one. Not sure what you mean by "valid," but at least some differences would be obvious even in these samples. A large different in contrast or significant image distortion would surely be easy to see, for example. It was just for fun, though. I guess many Leica users are too serious to ever have any fun. In a way, they remind me of Mac users (the same creeping paranoia that makes them believe that everyone else is out to get them). > Then the photos were taken from different locations. They were both taken from the same spot. > What's more, they were taken at different times ... One was taken in early afternoon, one was taken in late afternoon. > ... compare the sky in the two shots ... That was mostly weather. One was taken on a cloudless day, the other was taken on an overcast day. > Big no-no for a comparison. Those were the only photos I had handy. > Perhaps run through the minilab on different days, > by different operators, etc. Correct. > My original scans, displayed at 100% size, are the equivalent of 36x24 > enlargements. They correspond to 53 lp/mm. > > B.S.! The math is easy enough to do. > 1 - the scan resolutions given by the mfr's are *interpolated* > resolutions. Nikon gives optical resolutions. > 2 - the resolutions that you invite *comparison* of are > - as I said - of far lower resolution than that (700x900). I know. I was pointing out that I don't see any significant differences on the original scans, either. > 3 - even if you *are* getting a true 53 lp/mm, remember > that Velvia does better than 80 lp/mm, and that the 50 > Summicron-M exceeds that resolution (cite E. Puts). So does the lens on the Yashica T5, as far as I can tell. > 4 - What were your shutter speeds? If I tell you the shutter speeds, you'll be able to figure out which photo is which. Besides, I don't know what shutter speed the Yashica used. > 5 - What were the apertures used? See above. > I would guess not. I would guess that due to camera > movement, etc., that you are getting *less* than 50 lp/mm. If so, that would mean that the Summicron is no better for handheld work than the Yashica T5. Do you agree? > Were the cameras on big, heavy, well-damped tripods? No, everything was handheld. > No. An experiment without control(s) is uninterpretable; > hence it is not an experiment. The use of different targets > alone (Notre Dame at different times of day, under different > lighting conditions) disqulaifies your "experiment". Oh dear. So now what? > I agree that the T5 lens is amazing for its price. It is > certainly of professional quality and more than adequate > for many uses. BUT... Well... you've just implied above that the Summicron will give no better results unless you are using a big, heavy tripod, which is kind of the antithesis of the way most Leicas are used. > No, on a tripod shooting test targets (newspaper, immobile > landscapes [cliffs], etc.). Here again, is this the normal way in which most people use their Leicas? If I want to shoot from a tripod, I use one of my SLRs. > The differences are there, but are much more apparent > with the lenses used wide open. Perhaps so, but you've cited so many conditions necessary to see them that one wonders if they have any significance in real-world, everyday shooting. > A huge difference is that the Yaschica/Zeiss lens is rather flare > prone, even with a makeshift shade. I haven't checked this. Sounds like an interesting experiment. I'll try it. > Your 'experiment' would not reveal this critical real-world > difference. I'll try one that does, although I have no plans of actually pointing the cameras into the sun. Near the sun, perhaps. I have some slides taken into the sun through trees ... let's see ... true, no obvious flare there. I haven't taken any with the T5 to compare, though. > I don't want to sell either one; I am not going to take the > 35 Summilux ASPH out on the Gulf of Maine in a small (14') > research boat. That's what the T5 (and the old Ricoh fitted > with used Pentax SMC lenses) are for. That is my logic as well. The UV filter on my Leica costs as much as the T5. > If you're not, you can either choose not to care (a perfectly > valid choice), or you can blather on about how there's > no 'real' difference between a $200 P/S and a $2000 lens. I haven't blathered at all. I've just watched others jump to the defensive with respect to Leica lenses, even though nobody is under attack. Interesting. -- Anthony