Part I is here<\/a>.<\/p>\n These were taken mostly at full aperture unless otherwise noted, with AutoISO. Absent minor correction of leaning verticals the images are pretty much SOOC. For ISOs of 3,200 and above I used LRc’s excellent ‘Denoise’ feature. It takes out digital noise without destroying definition:<\/p>\n My previous experience with the Sigma 35mm f\/1.4 Art lens suggested that Sigma’s quality control was less than stellar, with the autofocus being significantly off. Sigma makes the UD11 dock<\/a> but it appears that it does not permit correction of autofocus errors, serving only to adjust manual focus collar rotation speed. It also allows downloading of the latest firmware but you can do that without a dock. Anyway, it appears I have lucked out as far as focus accuracy goes. The Leica SL2-S does not have a function to correct for lens autofocus errors, so that’s not a solution if your lens’s focus is off.<\/p>\n The outstanding in-camera correction of distortion and vignetting is very much visible here. Flare – check the light globe far right – is very well controlled.<\/p>\n Performance at 20mm is exemplary, with little resolution gain from stopping down. There is no issue with using the lens wide open when it comes to rendering of details. This is a very high dynamic range image, testing the SL2-S’s (Sony BSI?) 24mp sensor to the limit. It acquits itself well, even though a 2019 design.<\/p>\n Check the detail rendering of the mesh behind the Hal Davis signage.<\/p>\n Obligatory brick wall. Again, the correction of distortion and vignetting is remarkable. Corner definition is all you could ask for.<\/p>\n There’s no need to stop down for best resolution at 200mm, as the above proves.<\/p>\n A few more snaps to round out this piece. The outdoors were very smoky from forest fires and an occasional touch on LRc’s Contrast slider was called for, though the lens delivers good contrast otherwise.<\/p>\n Check the definition of the lettering at the lower right in the large version.<\/p>\n Conclusion:<\/b> A fine ‘walk about’ lens, small, light with no excuses needed for performance at any aperture. This one optic easily replaces two zooms or half a dozen primes in your kit bag. As the last image in Part I<\/a> discloses the 20-200mm Sigma is also a capable macro lens. A fine optical accomplishment by the designers in Aizu, Japan. Sharing the tasks of aberration correction between the hardware team (coma, spherical and chromatic aberrations) and the software team (distortion and vignetting) is surely the wave of the future. <\/p>\n","protected":false},"excerpt":{"rendered":" Some snaps. For an index of all Leica-related articles click here. Part I is here. These were taken mostly at full aperture unless otherwise noted, with AutoISO. Absent minor correction of leaning verticals the images are pretty much SOOC. For ISOs of 3,200 and above I used LRc’s excellent ‘Denoise’ feature. It takes out digital … Continue reading Sigma 20-200mm zoom lens on the Leica SL2-S – Part II<\/span>
\n
\n![](\"http:\/\/www.pindelski.org\/Blog2\/Sigma_test_01.jpg\")
<\/a>
\nAutofocus on the little boy is spot on. 200mm, ISO 12,500.
\nClick the image for a larger version.<\/I>
\n<\/center><\/p>\n
\n![\"\"](\"http:\/\/www.pindelski.org\/Blog2\/Sigma_test_02.jpg\")
\nNo evidence of chromatic aberration, 113mm, ISO 400.<\/I>
\n<\/center><\/p>\n
\n![\"\"](\"http:\/\/www.pindelski.org\/Blog2\/Sigma_test_03.jpg\")
\nCorner to corner resolution. 45mm, ISO 6,400.<\/I>
\n<\/center><\/p>\n
\n
\n![](\"http:\/\/www.pindelski.org\/Blog2\/Sigma_test_04.jpg\")
<\/a>
\nThe Declaration of Independence.
\nStopped down to f\/8. Outstanding resolution – check the big version.
\n65mm, ISO 6,400.
\nClick the image for a larger version.<\/I>
\n<\/center><\/p>\n
\n
\n![](\"http:\/\/www.pindelski.org\/Blog2\/Sigma_test_05.jpg\")
<\/a>
\nStopped down to f\/4.8.
\n20mm, ISO 2,200.
\nClick the image for a larger version.<\/I>
\n<\/center><\/p>\n
\n![\"\"](\"http:\/\/www.pindelski.org\/Blog2\/Sigma_test_06.jpg\")
\nAnother example of fine flare control. 78mm, ISO 3,200.<\/I>
\n<\/center><\/p>\n
\n
\n![](\"http:\/\/www.pindelski.org\/Blog2\/Sigma_test_07.jpg\")
<\/a>
\nStopped down to f\/8.
\n20mm, ISO 12,500.
\nClick the image for a larger version.<\/I>
\n<\/center><\/p>\n
\n
\n![](\"http:\/\/www.pindelski.org\/Blog2\/Sigma_test_08.jpg\")
<\/a>
\n150mm, ISO 280.
\nClick the image for a larger version.<\/I>
\n<\/center><\/p>\n
\n
\n![](\"http:\/\/www.pindelski.org\/Blog2\/Sigma_test_09.jpg\")
<\/a>
\n33mm, ISO 100.
\nClick the image for a larger version.<\/I>
\n<\/center><\/p>\n
\n
\n![](\"http:\/\/www.pindelski.org\/Blog2\/Sigma_test_10.jpg\")
<\/a>
\n200mm, ISO 200.
\nClick the image for a larger version.<\/I>
\n<\/center><\/p>\n
\n
\n![](\"http:\/\/www.pindelski.org\/Blog2\/Sigma_test_11.jpg\")
<\/a>
\n95mm, ISO 560.
\nClick the image for a larger version.<\/I>
\n<\/center><\/p>\n
\n![\"\"](\"http:\/\/www.pindelski.org\/Blog2\/Sigma_test_12.jpg\")
\n123mm, ISO 140.<\/I>
\n<\/center><\/p>\n
\n![\"\"](\"http:\/\/www.pindelski.org\/Blog2\/Sigma_test_13.jpg\")
\n31mm, ISO 1,600.<\/I>
\n<\/center><\/p>\n
\n![\"\"](\"http:\/\/www.pindelski.org\/Blog2\/Sigma_test_14.jpg\")
\n71mm, ISO 1,600.<\/I>
\n<\/center><\/p>\n
\n![\"\"](\"http:\/\/www.pindelski.org\/Blog2\/Sigma_test_15.jpg\")
\n191mm, ISO 100.<\/I>
\n<\/center><\/p>\n
\n![\"\"](\"http:\/\/www.pindelski.org\/Blog2\/Sigma_test_16.jpg\")
\nA touch of Saul Leiter<\/a>. 91mm, ISO 200.<\/I>
\n<\/center><\/p>\n