Resolution & Sharpness
Sharpness and contrast are often considered to be the standard measure of lens quality. Although it’s just one component of the captured image, the detail refracted onto the image sensor directly impacts the amount of information in the captured file, independent of manipulation or post-processing.


Our battery of standardized resolution tests are shot in a professional lab and run through Imatest software, the industry leader for image quality evaluation. Test images for each lens were shot with both a Panasonic and an Olympus Micro Four Thirds camera body to distinguish the performance of each optic from its interplay with a given imaging system.


Camera settings were standardized across lenses and camera bodies for the test sequences; focal length and aperture settings, along with target distance, were varied through multiple trials.


We report results for lens resolution in two measures: MTF50 (resolved detail) and SQF (perceived sharpness at various viewing distances). Results are expressed in Line Widths per Picture Height (LW/PH), a unit of measurement for resolution that takes into account the output file size.


Resolution: MTF50

MTF data is expressed in two graphs; the top graph depicts the performance of both lenses across their aperture range, while the bar graph below shows the average sharpness of each lens across all trials.

 

 
Panasonic’s Micro Four Thirds kit lens is superior in both measures. The top graph, showing tests across the aperture range, indicates the greatest disparity in sharpness between the lenses occurs at the widest aperture settings: roughly f/4 to f/8. It appears the Panasonic lens suffers more from diffraction at mid-high aperture settings, with the Olympus lens capturing more fine detail from f/11-f/18. 


The relative sharpness of both lenses, averaged across all tests, yielded a difference in performance of roughly 4.8% in favor of Panasonic. The Lumix G Vario Micro Four Thirds kit lens resolved 2012 LW/PH on average, while Olympus’s M.Zuiko Micro Four Thirds kit lens rendered an average of 1911 LW/PH.


Resolution: SQF
Subjective Quality Factor (SQF) is a unit of measurement expressing the perceived sharpness of an image file, when viewed by a person (taking into account the natural characteristics of human vision) at a given distance and print size. SQF results are generally in line with the pure MTF data, though the subjective measure gives some perspective on the actual “real world” extent of the performance gap.


Mouseover the image below to toggle between the SQF results from both lenses. As you can see, the lenses perform quite similarly, though prints from the Panasonic G Vario lens will appear slightly sharper than those from the Olympus M.Zuiko kit lens, regardless of the camera body used.