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Blog Articles Medium Format Mirrorless L-Mount DSLR Zeiss Leica Making Sharp Images BW+IR

lens skew

Optical misalignment causing asymmetric sharpness (lack of rotational symmetry), difficult to distinguish from lens mount / sensor parallelism

See also: focus skew, lens mount / sensor parallelism, quality control
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2022-05-13 Fujifilm Quality Control... Decided to Be Picky: Returned the Fujifilm GF 35-70mm f/4.5-5.6 WR + Reader Comments

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

2020-10-23 Compared @ 14mm: Swing and Tilt, Optical Decentering — two Sony FE 12-24mm f/2.8 GM and Sigma FE 14-24mm f/2.8 DG DN Art

2020-10-18 Analyzing Swing and Tilt of Sony A7R IV with Two Samples of Sony FE 12-24mm f/2.8 GM

2020-10-18 Swing and Tilt: Subject Distance vs Lens Focusing Offset

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

2020-10-01 Sony FE 12-24mm f/2.8 GM Aperture Series: Big Tree at Bend in Alpine Creek (jaw-dropping focus shift and lens skew)

2019-12-01 Phase One IQ4 + Schneider Kreuznach LS 40-80mm f/4-5.6 Aperture Series @ 80mm: Mosaic

2019-12-01 Phase One IQ4 + Schneider Kreuznach LS 40-80mm f/4-5.6 Aperture Series @ 40mm: Mosaic

2019-12-01 Phase One IQ4 + Schneider Kreuznach LS 40-80mm f/4-5.6 Aperture Series @ 55mm: Mosaic

2019-11-30 Phase One IQ4 + Schneider Kreuznach LS 240mm f/4.5 IF Aperture Series: Mosaic

2019-09-05 Fujifilm GF Lens Quality Control = Unacceptable

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)

2017-07-23 Sony 12-24mm f/4G Distortion: Uncorrected vs Corrected

2017-07-23 Reader Comment: Sony FE 12-24mm f/4 G Right Side Blur

2015-07-20 Sigma 24mm f/1.4 DG HSM Art Aperture Series: Bristlecone on Bare Hill, Checking for Lens Symmetry (Canon 5DS R)

2015-04-04 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

Camera and Lens Tolerances

Sharpness issues related to camera and lens tolerances and build quality..

1. Case Study: Severe Lens Skew (D800E, Samyang 14mm f/2.8)

Optical Behavior (Case Studies)

Illuminating examples of lens behavior..

1. Lens Skew (Nikon D800E, Sigma 35/1.4)
2. Lens Asymmetry/Blur With Fuji X100
3. Lens Asymmetry/Blur With Sony NEX-7 + 24mm ƒ/1.8 Sonnar

Panasonic Lumix S PRO 50mm f/1.4

Premium fast normal lens for L-Mount..

1. Aperture Series: Pines by Creek (Panasonic S1R)
2. Shootout: Leica 50mm f/1.4 SL vs Panasonic LUMIX S PRO 50mm f/1.4: Rotten Log

Leica 50mm f/1.4 Summilux-SL ASPH

Fast apochromatic prime lens for L-Mount cameras..

1. Shootout: Leica 50mm f/1.4 SL vs Panasonic LUMIX S PRO 50mm f/1.4: Rotten Log

Leica 50mm f/2 APO-Summicron-SL ASPH

Fast short normal lens for L-Mount cameras..

1. Lens Skew, Optical Swing
2. Aperture Series: Peaks and Valley, Mt Conness Southern Spur
3. Aperture Series: Smoky Sunset, Piper Mountain Wilderness
4. Aperture Series: View North to Mt Conness from Puppy Dome
5. Aperture Series: Backlit Pines among Glacial Erratics fronting Granite Cliff
6. Aperture Series: Backlit Open Forest
7. Aperture Series: View Through Trees towards Cloud’s Rest

Pentax HD FA 15-30mm f/2.8 ED SDM WR

Full frame ultra wide angle zoom..

1. Aperture Series @ 30mm, with Pixel Shift: Mosaic (Pentax K-1 SuperRes)

Tamron SP 15-30mm f/2.8 Di VC USD

Tamron’s ultra wide to medium fast zoom..

1. Tamron 15-30mm vs Nikon 14-24/2.8G [Bad Sample] (Pescadero Creek, Nikon D810)

Sigma 24-35mm f/2 DG HSM Art

Mid-range optimized groundbreaking f/2 zoom..

1. Shootout: vs Sigma 24-105mm f/4A: Colorful Creek

Sigma 24mm f/1.4 DG HSM Art

Sigma’s fast high performance wide angle..

1. Aperture Series: Checking for Lens Symmetry, Bristlecone on Bare Hill (Canon 5DS R)

Sigma 35mm f/1.4 DG HSM Art

Sigma’s fast and affordable moderate excellent wide angle..

1. Lens Skew (Nikon D800E)
2. Lens Skew Confirmation (Nikon D800E)

Nikon AF-S 300mm f/2.8 VR II

Does high price guarantee quality control and superb images?.

1. Skewed Plane of Focus

Samyang 14mm f/2.8

Ultra wide angle lens for Canon and Nikon..

1. Lens Skew / Asymmetry Focus Bracket
2. Aperture Series: Wyman Cabin

Schneider Kreuznach LS 80mm f/2.8

Compact normal 54mm equivalent for Phase One XF system.

1. Aperture Series: Mosaic (IQ4 150)

Schneider Kreuznach LS 150mm f/2.8 IF

Medium telephoto 100mm equivalent for Phase One XF system.

1. Aperture Series: Mosaic (IQ4 150)

Schneider Kreuznach LS 240mm f/4.5 IF

Long telephoto 162mm equivalent for Phase One XF system.

1. Aperture Series: Mosaic (IQ4 150)

Fujifilm GFX100S/100 Comparisons

Is 100 better than 45/50/60 megapixels?.

1. SHOOTOUT: Fujifilm GF 23mm f/4 on GFX100S vs Sony FE 12-24mm f/2.8 GM on Sony A1

Fujifilm GF 20-35mm f/4 R WR

Compact wide angle.

1. Examples: Twenty Lakes Basin

Fujifilm GF 23mm f/4 R WR

Ultra wide angle equivalent to 19mm f/3.3. .

1. Focus Stacking Examples, Eastern Sierra (GFX100)

Fujifilm GF 32-64mm f/4 R LM WR

Mid-range zoom lens equivalent to 26-53mm f/3.3..

1. Examples: Eastern Sierra (GFX 50S)
2. Aperture Series @32mm: Cerro Gordo Museum (Focus Variability + Right-Side Blur) (GFX 50S)

Fujifilm GF 35-70mm f/4.5-5.6

Compact wide angle.

1. Aperture Series @ 70mm: Fresh Snow on White Mountain Forested Hills

Fujifilm GF 45-100mm f/4 R LM OIS WR

Slightly long zoom lens equivalent to 37-82mm f/3.3..

1. Aperture Series @ 56mm: Alabama Hills Desert Wash, Sunrise View To Mt Whitney

Fujifilm GF 63mm f/2.8 R WR

Standard normal lens equivalent to 52mm f/2.3..

1. Compared: 63mm f/2.8 vs 32-64mm f/4 (GFX 50S, Pine Creek South Fork)

Hasselblad XCD 35-75mm f3.5-4.5

Normal lens equivqlent to 53mm..

1. Aperture Series @ 75mm: View over Alabama Hills Granite Formations to Last Orange Light on Mt Whitney

Hasselblad XCD 65mm f/2.8

Normal lens equivqlent to 53mm..

1. Aperture Series: Sagebrush Nook, Alabama Hills
2. Aperture Series: View Over Brushy Desert to High Peaks, Very Late Dusk
3. Aperture Series: View Over Alabama Hills Formations to Mt Whitney Range, Dusk
4. Aperture Series: View Over Alabama Hills Formations, Last Light on High Peaks

Hasselblad XCD 80mm f/1.9

Moderate telephoto..

1. Aperture Series: Alabama Hills Formations, Late Dusk
2. Aperture Series: Bristlecone Graveyard, Dusk

Hasselblad H4D 50 Megapixel Medium Format DSLR

How does Hasselblad’s 3rd generation medium format entry measure up?.

1. Examples with HCD 28mm f/4 (Yosemite)

Leica S Examples

Examples and comparison from the various lenses.

1. Leica 180mm f/3.5 APO-Elmar-S — Asymmetry

Brand-new Blur

Blurry lenses right out of the box..

1. Brand-new Blur Overview
2. Blurry Canon EF 70-200mm f/4L IS
3. Blurry Canon EF85mm f/1.8
4. Blurry Canon EF 100mm f/2.8 IS
5. Blurry Nikon AF-S 70-200mm f/2.8G VR II
6. Blurry Nikon AF-S 300mm f/2.8G VR II
7. Asymmetry with Leica 180mm f/3.5 APO-Elmar-S
8. How to Test a Lens for Issues

Canon RF 15-35mm f/2.8L IS USM

Fast ultra wide zoom lens..

1. Examples: Eastern Sierra

Nikon NIKKOR Z 14-30mm f/4 S

Ultra wide compact zoom for Nikon Z cameras..

1. Aperture Series @ 30mm: Bleached Trees in Old Beaver Pond

Nikon NIKKOR Z 85mm f/1.8 S

Fast portrait telephoto for Nikon Z..

1. Aperture Series: Pre-Sunrise View South over Patriarch Grove

Sony FE 14mm f/1.8 GM

Ultra high performance extreme wide angle..

1. Aperture Series: Greenstone Lake

Sony FE 20mm f/1.8 G

Compact ultra-wide angle lens..

1. Examples: Inyo National Forest
2. Aperture Series: Alabama Hills Granite Monolith, Sunrise
3. Aperture Series: View Towards Big Pine and Eastern Sierra, Dusk

Sony FE 35mm f/1.4 GM

High performance mild wide-angle..

1. Shootout vs Voigtlander FE 35/2 APO-Lanthar: Pine Creek Cliffs
2. Shootout vs Voigtlander FE 35/1.4 GM: Patriarch Grove

Sony FE 35mm f/1.4 Distagon ZA

Fast and gorgeous moderate wide angle Zeiss design..

1. Examples at f/1.4, Bad Sample Lens #1, Skew/Asymmetry (Pescadero Creek, A7R)
2. Examples: Bad Sample Lens #2, Skew/Asymmetry (A7R II)

Sony Planar T* FE 50mm f/1.4 ZA

Fast high performance normal lens of Zeiss design..

1. Shootout vs Zeiss Loxia 50/2: Spuller Lake View to Mt Conness (Sony A7R II, Bad Sample of Sony 50/1.4)

Sony FE 50mm f/1.2 GM

High performance, high speed..

1. Lens Skew
2. Aperture Series: Rainstorm Over White Mountains
3. Aperture Series: Late Day View to White Mountain Peak
4. Shootout vs Sony FE 24-70mm f/2.8 GM II, Voigtlander FE 50/2 (Deck and Roof)

Sigma FE 14mm f/1.4 DG DN Art

Super-fast ultra-wide astrophotography lens..

1. Aperture Series: Bristlecone View to White Mountain Peak

Sigma FE 14-24mm f/2.8 DG DN Art

Native-mount ultra wide angle high performance zoom for mirrorless..

1. Distortion @ 14mm
2. Distortion @ 24mm
3. Aperture Series @ 14mm: Teak Bench Closeup
4. Aperture Series @ 24mm: Teak Bench Closeup
5. Aperture Series @ 24mm: Buckeye along Storm Drain
6. 3-Way Shootout @ 18mm: Mosaic (Sony A7R IV)
7. Compared @ 14mm: Swing and Tilt, Optical Decentering — Sigma FE 14-24mm f/2.8 DG DN Art and Two Sony FE 12-24mm f/2.8 GM

Sigma FE 24-70mm f/2.8 DG DN Art

Native-mount mid-range zoom for mirrorless..

1. Aperture Series @70mm: View Past Lone Pine Campground to White Mountains

Sigma FE 45mm f/2.8 DG DN Contemporary

Compact native-mount normal lens..

1. Aperture Series: Mosaic (Sony A7R IV)

Voigtlander FE 21mm f/1.4 Aspherical

Fast high performance manual focus wide angle..

1. Shootout: Voigtlander FE Nokton 21mm f/1.4 Aspherical vs Zeiss Loxia 21mm f/2.8: Mosaic (Sony A7R IV)

Voigtlander FE 35mm f/2 APO-Lanthar Aspherical

High-grade manual focus wide-normal lens..

1. Shootout vs Sony FE 35/1.4 GM, Sigma FE 35/2 DG DN: Pine Creek Cliffs
2. Shootout vs Sony FE 35/1.4 GM: Patriarch Grove

Voigtlander FE 50mm f/2 APO-Lanthar Aspherical

High-grade manual focus normal lens..

1. Shootout vs Sony FE 24-70mm f/2.8 GM II (Deck and Roof)

Voigtlander FE 65mm f/2 Macro APO-Lanthar Aspherical

Ultra high grade macro all-arounder..

1. Shootout @ 65mm vs Voigtlander FE 65/2 APO-Macro-Lanthar (Deck and Roof)

Sony FE 12-24mm f/2.8 GM

Fast extreme wide angle zoom..

1. Compared @ 14mm: Swing and Tilt, Optical Decentering —two Sony FE 12-24mm f/2.8 GM and Sigma FE 14-24mm f/2.8 DG DN Art
2. Aperture Series @ 17mm: Big Tree at Bend in Alpine Creek

Sony FE 12-24mm f/4 G

Extreme wide angle zoom..

1. Imaging Performance @ 12mm, Single Frame vs Stacked: Pine at Morgan Lake
2. Imaging Performance @ 24mm, Single Frame vs Stacked: Downed Tree, Last Kiss of Sunlight
3. 3-Way Shootout @ 18mm: Mosaic (Sony A7R IV)

Sony FE 16-35mm f/2.8 GM

Pro-grade f/2.8 wide angle zoom..

1. Aperture Series @ 35mm: Mosaic (Sony A7R IV)
2. 3-Way Shootout @ 18mm: Mosaic (Sony A7R IV)
3. 3-Way Shootout @ 24mm: Rock Creek Meadow

Sony FE 24-70mm f/2.8 GM II

Premiere mid-range zoom for Sony full frame mirrorless.

1. Shootout @ 50mm vs Voigtlander FE 50/2 APO-Lanthar (Deck and Roof)
2. Shootout @ 65mm vs Voigtlander FE 65/2 APO-Macro-Lanthar (Deck and Roof)

Panasonic Lumix G LEICA DG MACRO-ELMARIT 45mm f/2.8 ASPH MEGA O.I.S

A macro lens with high performance..

1. Examples: Build Quality — Lens Skew Blur on Left
2. Examples: Bristlecones and Yosemite

Zeiss Loxia 21mm f/2.8 Distagon

Outstanding ultra wide angle performer..

1. Shootout: Zeiss Loxia 21mm f/2.8 vs Voigtlander FE Nokton 21mm f/1.4 Aspherical Mosaic (Sony A7R IV)

Leica 50mm f/2 APO-Summicron-M ASPH

High performance but flawed 50mm normal lens..

1. Skewed Plane of Focus
2. Aperture Series: Church Mosaic and Lens Skew (M240)

Voigtlander M 28mm f/2 Ultron

Compact performer..

1. Aperture Series: Cosco Container (M11 Monochrom)

Blog posts, reverse chronological

2022

2022-05-13 Fujifilm Quality Control... Decided to Be Picky: Returned the Fujifilm GF 35-70mm f/4.5-5.6 WR + Reader Comments

2021

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

2020-10-23 Compared @ 14mm: Swing and Tilt, Optical Decentering — two Sony FE 12-24mm f/2.8 GM and Sigma FE 14-24mm f/2.8 DG DN Art

2020-10-18 Analyzing Swing and Tilt of Sony A7R IV with Two Samples of Sony FE 12-24mm f/2.8 GM

2020-10-18 Swing and Tilt: Subject Distance vs Lens Focusing Offset

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

2020-10-01 Sony FE 12-24mm f/2.8 GM Aperture Series: Big Tree at Bend in Alpine Creek (jaw-dropping focus shift and lens skew)

2019

2019-12-01 Phase One IQ4 + Schneider Kreuznach LS 40-80mm f/4-5.6 Aperture Series @ 80mm: Mosaic

2019-12-01 Phase One IQ4 + Schneider Kreuznach LS 40-80mm f/4-5.6 Aperture Series @ 40mm: Mosaic

2019-12-01 Phase One IQ4 + Schneider Kreuznach LS 40-80mm f/4-5.6 Aperture Series @ 55mm: Mosaic

2019-11-30 Phase One IQ4 + Schneider Kreuznach LS 240mm f/4.5 IF Aperture Series: Mosaic

2019-09-05 Fujifilm GF Lens Quality Control = Unacceptable

2017

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)

2017-07-23 Sony 12-24mm f/4G Distortion: Uncorrected vs Corrected

2017-07-23 Reader Comment: Sony FE 12-24mm f/4 G Right Side Blur

2015

2015-07-20 Sigma 24mm f/1.4 DG HSM Art Aperture Series: Bristlecone on Bare Hill, Checking for Lens Symmetry (Canon 5DS R)

2015-04-04 Tamron SP 15-30mm f/2.8 Di VC USD: Focusing Problems and Lens Skew

2013

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