Olympus M.ZUIKO DIGITAL 40-150mm 1:4-5.6 ED R MSC - Review / Test Report - Analysis
Lens Reviews -
Sunday, 25 November 2012 15:13
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The MFT system applies auto-correction for distortion so its usually not an issue to worry about. The corrected images show less than 1% barrel (40mm) to pincushion (70mm+) distortion. The RAW (=uncorrected) data suggests a different characteristic - not really in the medium to long range but there's a strong degree (4%) of barrel distortion at 40mm.
If you move your mouse cursor over the image you can switch to the corresponding non-corrected results.
The lens has a pretty moderate vignetting characteristic. At max. aperture the light falloff remains below 0.6EV and thus also below really disturbing levels. If you stop down just a little bit, the issue gets negligible already.
The M.Zuiko 40-150mm R may not be a high performance lens but it does a decent job in terms of resolution. At 40mm (f/4-11) the results are generally very good in the image center and good to very good in the outer image field. Moving out to 70mm, there's only a marginal decrease in quality and it is still fine at 100mm. The resolution is somewhat more reduced at 150mm with a good to very good center and good borders. The extreme corners are soft at f/5.6 so you should stop down to f/8 here - this is a good idea anyway in order to boost the contrast at this focal length.
Below is a simplified summary of the formal findings. The chart shows line widths
per picture height (LW/PH) which can be taken as a measure for sharpness.
If you want to know more about the MTF50 figures you may check out the corresponding
Chromatic Aberrations (CAs)
Lateral CAs (color shadows at strong transitions) are a bit of an issue at the wide end (40mm) of the zoom range where they vary between 1.3-1.8px on the average at the image borders. This can be visible in certain scenes. However, there's nothing to worry about at longer focal lengths.