Archived posting to the Leica Users Group, 1998/09/28
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]- --============_-1305111023==_ma============ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable With the new APO-Summicron -M 2/90 ASPH almost ready for delivery, I think it appropriate to give the results of the currently available versions of all 90mm lenses old and new. (2,8 and 2,0). Summicron 90mm (#1580510 and #3643078) The first version of the Summcron (6 lens elements) has been produced from 1958 till 1980. With 22 years production time it has one of the longest life cylcles of all Leica lenses. The Elmar 3,5/50 is number one with 36 years, the Elmar 4/90 (3 lenselements) with four years almost a flash in the night. Most Leica lenses stay in production for 10 to 15 years. Progress in the wold of optics has its own dynamics. The first series of the Summicron has been mounted in the mount of the Summarex 1,5/85. (The version I tested). Weight and volume demanded a redesign. In 1980 the 5 element version (type 2) has been introduced: less weight and volume. The number of lenselements with plane surfaces has been increased to lower production cost. This version has much more contrast and transparancy than the older version. At full aperture both lenses perform well in the center (an image circle of =B112mm). Fine detail is clearly visible in the older version (type 1), with more crispness in the newer version. Outer zones and corners are much improved in the type 2 version. At f/2,8 the contrast improves and the center quality now extends to the corners. The type 1 version needs 4 to 5,6 for the same image quality. To be specific: the type 1 version at full aperture in the center gives good quality for the fine details, at 2,8 the very fine details are clearly visible and at 4.0 the extremely fine details are brought in. The type 2 version shows these extremely fine details alreay at full aperture. Colour fringes around object contours are visible in the outer zones of the type 1 where the type 2 has none. The type 1 also exhibits flare around point light sources. where the type 2 has better flare reduction. Close-up performance (=B1 1meter) at full aperture of the type 1 version is to be avoided. One needs to stop down to 5,6 or 8,0 to get the performance the type 2 delivers at wider apertures. The specific lens of the type 1 version is slightly decentered and shows curvature of field. The type 2 is perfect as centering goes, but also exhibits curvature of field, (less than its predecessor) which degrades the full aperture performance. (Tele-)Elmarit(-M) 90mm (#1919463, #2491424, #3378681 and #3678697). These lenses are visible proof of Leica's long search for an optimum 90mm at 2,8. The first Elmarit has high contrast at full aperture over the entire image field. At f/4,0 extremely fine detail is clearly and crisply rendered. The current Elmarit-M however is at full aperture better than the Elmarit. The current version has the ability to render microscopically fine detail. At f/4,0 an extremely and rarely encountered high image quality has been reached. This Elmarit-M is much better at full aperture than its three predecessors (Elmarit, Tele-Elmarit and Tele-Elmarit-M) at f/4,0 to f/5,6. These three are notably weaker in the outer zones and corners where contrast is lower and 'only' very fine details are very well rendered. In the center (image circle =B1 12mm) the performance of the Elmarit and the Tele-Elmarit-M are about equal. The Tele-Elmarit has a fractionally lower contrast, showing fine details with a slightly softer edge. Close-up the performance of both Elmarit versions is at full aperture very good with crisp rendition of very fine detail, the -M version having better corner performance. At f/5,6 the corners are as good as the center for the older version. Both Tele-Elmarit versions have lower contrast at full aperture, showing fine deatils with clear visibilty. Here we need to stop down to 5.6 for really good performance. The Elmarit has decentring and field curvature, both Tele-Elmarits are better in both respects. And the Elmarit-M? Perfect here. Astigmatism and colour fringing decreases per generation and is relegated to the far corners. Conclusion: The best of all six lenses is with a clear advantage the Elmarit-M 2.8/90: At full aperture much better than its siblings at 4 to 5,6 and even better than the Summicron-M at 2,8. Tee Elmarit-M approaches the theoretical level of a lens as good at every aperture and at every distance and over the whole image field. With this lens the true quality of modern low speed emulsions can be exploited to never imagined heights. The Elmarit is number two, the Tele-Elmarit-M is number three and the Tele-Elmarit number four. The Summicron-M is heavier, more expensive and has generally a lower performance. The Summicron (type 1) has to be stopped down to get the performance of the Summicron-M at full aperture. Note: In Eastlands book he notes that all Leica lenses old and new are excellent performers. Well that is true to a certain extent. At enlargements of 10 times the differences noted in this report are really visible and cannot be overlooked. Higher contrast and extremely fine details rendered crisply and with lucidiity over the whole image field are the hall mark of modern Leica lenses. The definition of 'excellence' certainly needs a revision. Erwin - --============_-1305111023==_ma============ Content-Type: text/enriched; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable <fontfamily><param>Times</param><bigger><bigger>With the new APO-Summicron -M 2/90 ASPH almost ready for delivery, I think it appropriate to give the results of the currently available versions of all 90mm lenses old and new. (2,8 and 2,0).=20 Summicron 90mm (</bigger></bigger></fontfamily><bigger><bigger><fontfamily><param>Helvetica= </param>#1580510 and #3643078) The first version of the Summcron (6 lens elements) has been produced from 1958 till 1980. With 22 years production time it has one of the longest life cylcles of all Leica lenses. The Elmar 3,5/50 is number one with 36 years, the Elmar 4/90 (3 lenselements) with four years almost a flash in the night. Most Leica lenses stay in production for 10 to 15 years. Progress in the wold of optics has its own dynamics. The first series of the Summicron has been mounted in the mount of the Summarex 1,5/85. (The version I tested). Weight and volume demanded a redesign. In 1980 the 5 element version (type 2) has been introduced: less weight and volume. The number of lenselements with plane surfaces has been increased to lower production cost. This version has much more contrast and transparancy than the older version.=20 At full aperture both lenses perform well in the center (an image circle of =B112mm). Fine detail is clearly visible in the older version (type 1), with more crispness in the newer version.=20 Outer zones and corners are much improved in the type 2 version. At f/2,8 the contrast improves and the center quality now extends to the corners. The type 1 version needs 4 to 5,6 for the same image quality. To be specific: the type 1 version at full aperture in the center gives good quality for the fine details, at 2,8 the very fine details are clearly visible and at 4.0 the extremely fine details are brought in. The type 2 version shows these extremely fine details alreay at full aperture.=20 Colour fringes around object contours are visible in the outer zones of the type 1 where the type 2 has none. The type 1 also exhibits flare around point light sources. where the type 2 has better flare reduction.=20 Close-up performance (=B1 1meter) at full aperture of the type 1 version is to be avoided. One needs to stop down to 5,6 or 8,0 to get the performance the type 2 delivers at wider apertures. The specific lens of the type 1 version is slightly decentered and shows curvature of field. The type 2 is perfect as centering goes, but also exhibits curvature of field, (less than its predecessor) which degrades the full aperture performance.=20 (Tele-)Elmarit(-M) 90mm (#1919463, #2491424, #3378681 and #3678697). These lenses are visible proof of Leica's long search for an optimum 90mm at 2,8. The first Elmarit has high contrast at full aperture over the entire image field. At f/4,0 extremely fine detail is clearly and crisply rendered. The current Elmarit-M however is at full aperture better than the Elmarit. The current version has the ability to render microscopically fine detail. At f/4,0 an extremely and rarely encountered high image quality has been reached. This Elmarit-M is much better at full aperture than its three predecessors (Elmarit, Tele-Elmarit and Tele-Elmarit-M) at f/4,0 to f/5,6. These three are notably weaker in the outer zones and corners where contrast is lower and 'only' very fine details are very well rendered. In the center (image circle =B1 12mm) the performance of the Elmarit and the Tele-Elmarit-M are about equal. The Tele-Elmarit has a fractionally lower contrast, showing fine details with a slightly softer edge. =20 Close-up the performance of both Elmarit versions is at full aperture very good with crisp rendition of very fine detail, the -M version having better corner performance. At f/5,6 the corners are as good as the center for the older version. Both Tele-Elmarit versions have lower contrast at full aperture, showing fine deatils with clear visibilty. Here we need to stop down to 5.6 for really good performance.=20 The Elmarit has decentring and field curvature, both Tele-Elmarits are better in both respects. And the Elmarit-M? Perfect here. Astigmatism and colour fringing decreases per generation and is relegated to the far corners.=20 Conclusion: The best of all six lenses is with a clear advantage the Elmarit-M 2.8/90: At full aperture much better than its siblings at 4 to 5,6 and=20 even better than the Summicron-M at 2,8. Tee Elmarit-M approaches the theoretical level of a lens as good at every aperture and at every distance and over the whole image field. With this lens the true quality of modern low speed emulsions can be exploited to never imagined heights. The Elmarit is number two, the Tele-Elmarit-M is=20 number three and the Tele-Elmarit number four.=20 The Summicron-M is heavier, more expensive and has generally a lower performance. The Summicron (type 1) has to be stopped down to get the performance of the Summicron-M at full aperture.=20 Note: In Eastlands book he notes that all Leica lenses old and new are excellent performers. Well that is true to a certain extent. At enlargements of 10 times the differences noted in this report are really visible and cannot be overlooked. Higher contrast and extremely fine details rendered crisply and with lucidiity over the whole image field are the hall mark of modern Leica lenses. The definition of 'excellence' certainly needs a revision.=20 Erwin</fontfamily></bigger></bigger> - --============_-1305111023==_ma============--