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Lens Tests

| EF 28mm f1.8 USM | EF 50mm f1.4 USM | EF 100mm f2.8 Macro USM |

| EF 180mm f3.5L Macro | EF 180mm f3.5L Macro + EF 1.4X II  | EF 180mm f3.5L Macro + EF 2X II |

| EF 200mm f2.8L II | EF 200mm f2.8L II + EF 1.4X II | EF 200mm f2.8L II + EF 2X II | EF 200mm f2.8L II + EF 1.4X II+ EF 2X II |

| EF 300mm f4L IS | EF 300mm f4L IS + EF 1.4X II | EF 300mm f4L IS + EF 2X II | EF 300mm f4L IS + EF 1.4X II + EF 2X II |

| EF-S 18-55mm f3.5-5.6 | EF-S 10-22mm f3.5-4.5 USM | EF 17-40 f4L USM | EF 24-105mm f4L IS USM |

| Tamron SP 150-600mm f/5-6.3 Di VC |

| Primes | 17mm Region | 24mm Region | 28mm Region | 35mm Region | 50mm Region | 100mm Region | 300mm Region | 400mm Region | 600mm Region |

| EF 180mm f3.5L Macro + TCs | EF 200mm f2.8L II + TCs | EF 300mm f4L IS USM + TCs | Tests With the Kenko TC | Macro Tests |

| Filter Effect on Sharpness and AF | Flare and Filters | Image Stabilizer Tests | TC Sharpness | Best of the Best | Method | Understanding the Results | Real World 100% Crops | Tripod Tests | L-Plate Test |


EF 28mm f1.8 USM

| As Shot | CA Corrected | As Shot vs Corrected |

The EF 28mm f1.8 USM has a reputation for a sharp centre but soft edges and corners with high levels of chromatic aberration even on crop cameras. So these measurements are presented As Shot and exactly the same exposure corrected for CA in Adobe RAW. A summary comparison of the two is also given.

The CA correction applied was derived by quick visual examination and is shown in the below plot along with 2nd order curve fits.


fit red/cyan

fit blue/yellow




























These values were derived for a subject (the test target) at a relatively shot distance however test shots in the field suggest a similar value. Probably a substantial correction at any f-stop and distance will be obtained with -30 red/cyan. After some iteration the fit curve was produced giving a residual APS-C corner CA of around 0.5 pixel. ARC Correction XMP files.

The comparative test shows a significant improvement in the edge and corner sharpness after CA correction (fit curve) above f2.8. 

Peak centre sharpness occurs between f2.8 and f5.6. Peak corner sharpness occures at f8.

The following 100% crops show a real life case, all have been given standard capture sharpening of 0.7, 0, 300% USM edge masked and blended with a 65% luminosity.

The full frame @ f2

Ap As Shot fit curves CA Correction

Last Updated 05/06/2008

All Content 2005-16 Lester Wareham All Rights Reserved     

All material is supplied  as is and without warranty, use at your own risk.  

All opinions stated are the authors own.

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