Sharpness issues related to camera and lens tolerances and build quality..
How to verify a good sample and assess all aspects of lens performance..
Illuminating examples of lens behavior..
Premium fast normal lens for L-Mount..
Fast apochromatic prime lens for L-Mount cameras..
Fast short normal lens for L-Mount cameras..
The best becomes better..
Full frame ultra wide angle zoom..
Tamron’s ultra wide to medium fast zoom..
Mid-range optimized groundbreaking f/2 zoom..
Sigma’s fast high performance wide angle..
Sigma’s fast and affordable moderate excellent wide angle..
Ultra wide angle lens for Canon and Nikon..
Compact normal 54mm equivalent for Phase One XF system.
Medium telephoto 100mm equivalent for Phase One XF system.
Long telephoto 162mm equivalent for Phase One XF system.
Ultra wide angle equivalent to 19mm f/3.3. .
Mid-range zoom lens equivalent to 26-53mm f/3.3..
Slightly long zoom lens equivalent to 37-82mm f/3.3..
Ultra high speed telephoto equivalent to 90mm f/1.6..
High performance macro photography on medium format, equivalent to 99mm f/3.3..
Normal lens equivqlent to 53mm..
Normal lens equivqlent to 53mm..
A variety of 645 lens tests on the 645D.
How does Hasselblad’s 3rd generation medium format entry measure up?.
Sharpness and rendering..
Fast ultra wide zoom lens..
Ultra wide compact zoom for Nikon Z cameras..
Ultra high performance extreme wide angle..
Compact ultra-wide angle lens..
High performance mild wide-angle..
Fast and gorgeous moderate wide angle Zeiss design..
Fast high performance normal lens of Zeiss design..
High performance, high speed..
Native-mount macro length designed by Zeiss..
Native-mount ultra wide angle high performance zoom for mirrorless..
Native-mount mid-range zoom for mirrorless..
Ultra high speed native-mount moderate wide angle..
Compact native-mount normal lens..
High-grade manual focus wide-normal lens..
Fast extreme wide angle zoom..
Extreme wide angle zoom..
Pro-grade f/2.8 wide angle zoom..
Ultra wide angle lens adapted from DSLR, native E-mount, all manual..
Native Micro Four Thirds macro lens..
A macro lens with high performance..
How good is Leica quality control?.
High performance but flawed 50mm normal lens..
Blog posts, reverse chronological
2021-09-23 Video with Peter Karbe on how Leica designs and builds its Leica SL lenses
2021-09-23 Leica 50mm f/2 APO-Summicron-SL ASPH Aperture Series: Unacceptable Optical Swing (Lens Skew) + Reader Comments
2021-07-08 Sony FE 50mm f/1.2 GM Aperture Series: Example of Unacceptable Lens Skew
2020-10-18 Swing and Tilt: Subject Distance vs Lens Focusing Offset
2020-10-18 Analyzing Swing and Tilt of Sony A7R IV with Two Samples of Sony FE 12-24mm f/2.8 GM
2020-10-16 Update on Sony A7R IV Lens Mount / Sensor Parallelism, Lens Skew of Sony FE 12-24mm f/2.8 GM, Coming Field Shooting
2020-10-12 Lens Mount / Sensor Parallelism Inaccuracies Afflict All Brands
2020-10-08 Is It Even POSSIBLE to get a properly aligned Sony A7R IV?
2020-10-07 Sony A7R IV in for Repair of Lens Mount / Sensor Parallelism Problem
2020-10-01 Sony FE 12-24mm f/2.8 GM Aperture Series: Big Tree at Bend in Alpine Creek (jaw-dropping focus shift and lens skew)
2020-05-24 Hasselblad X1D II 50C: Operational and Focusing Bugs
2019-09-19 Sony A7R IV vs Lens Quality Control (all brands), Actual Increase in Resolution over the Sony A7R III
2019-09-18 Lens Quality Control as Revealed by Demanding Sony A7R IV 60MP Sensor
2019-09-05 Fujifilm GF Lens Quality Control = Unacceptable
2019-03-13 Sigma 24-70mm f/2.8 DG HSM Art Aperture Series @ 24mm: Alabama Hills Rainstorm Creek (Nikon D850)
2017-10-28 Nikon D850: the 2nd Sample is Off Also, both Skewed and Bad Flange Focal Distance
2017-10-01 Nikon D850: the Focusing Distance Issues Stem from a Sensor that is not Parallel to the Lens Mount (Nikon quality control issue)
2017-09-29 Nikon D850: Apparent Build Tolerance Error in Flange Focal Distance vs Optical Viewfinder, Causes Major Focus Error with Manual Focus Lenses and Focus Confirmation
2017-08-19 Sony 12-24mm f/4 G @ 12mm: Single Frame Performance at f/11 vs Focus Stacking at f/11 (Pine at Morgan Lake)
2016-05-08 Sony 85mm f/1.4 Scratchy/Noisy Focusing: I Heard None with my Sample
2016-04-09 Sony G Master 85mm f/1.4 Scratchy/Noisy Focus with Internal Wear
2015-08-18 Sony FE 35mm f/1.4 Distagon: Another Bad Sample with Skew / Asymmetry (A7R II)
2015-08-09 Sony 90mm f/2.8: Bad Sample (NOW WITH EXAMPLES)
2015-07-20 Sigma 24mm f/1.4 DG HSM Art Aperture Series: Bristlecone on Bare Hill, Checking for Lens Symmetry (Canon 5DS R)
2015-04-17 Sony FE 35mm f/1.4 Distagon: Quality Control Issues, Right Side Blur at f/1.4
2015-04-04 Tamron SP 15-30mm f/2.8 Di VC USD: Focusing Problems and Lens Skew
2013-09-06 Samyang 14mm f/2.8: Lens Skew Asymmetry
2013-08-12 Lens Skew with the Leica 50mm f/2 APO ASPH?
2013-02-22 Lens Skew Study added to MSI
2013-02-20 Sigma 35mm f/1.4 DG HSM: Lens Skew Confirmation (Alternate Scene)
2013-02-20 Sigma 35mm f/1.4 DG HSM: Lens Skew
2012-11-26 Sigma 35mm f/1.4 DG HSM: Quality Control Steps Up (“A1 MTF”)
2012-01-30 Sony NEX-7 + Sony 24mm f/1.8 Sonnar — “Bad Sample” Documented
2010-07-28 LensRentals.com discount code, and lens brand quality control
2010-07-11 Bad sample experience — Nikon AF-S 24mm f/1.4G
2009-12-10 Nikon 70-200/2.8G VR II bad sample
2009-10-05 Canon EF 100/2.8L IS macro lens bad sample