Olympus Pen-F Testing


In this section:

Resolution of the Pen-F with the 50mm f/2 Macro lens with Aperture in Standard Mode

Resolution of the Pen-F with the 50mm f/2 Macro with Aperture in HR Mode

Processing Time of the Pen-F in HR Mode

Standard Mode Aperture Series

The Olympus Pen-F is a µFT camera with a 20MP (5184x3888px) Four Thirds sensor (17.3x13mm).  I tested my Pen-F with the Olympus Zuiko Digital ED Four Thirds 50mm f/2 macro lens.  This lens has received high praise on the major review sites, and it was the lens that Imaging Resource used for their test images in their review of the Pen-F.

On the Pen-F, with a crop factor of 2, the 50mm lens gives an EFL of 100mm. To use this lens to provide AF and aperture adjustment on the Pen-F a smart (electronic) FT to µFT adapter is required which is equivalent to the Olympus MMF-1, MMF-2 and MMF-3 adapters.  Suitable and inexpensive equivalent generic adapters are readily available.

For the tests I used the black stepped triplet lines resolution chart developed by Dr J. C. Brown, as described here.  I mounted the printed charts on a chart board, positioned at the centre and edges, with other IQ test materials also mounted on the board. To provide constant uniform lighting I used two 500W (equivalent) daylight lamps. 

With the camera on a tripod with a quick release plate, I carefully adjusted the distance of the tripod from the chart board so that the image of the centre resolution chart gave a height of 400 pixels for the vertical scale line.  I tested the lens at all aperture settings from f/2 to f/22, in Standard (20MP) mode with the Pen-F at 80 ISO (Low ISO) throughout. 

The full series of OOC JPG test images from f/2 to f/22 can be found here.

The ORF file for the f/5 case can be downloaded here. The image below is the OOC 20MP JPG from that file (click on the image for the full 20MP size):

Standard Mode, 20MP, 50mm, f/5, 80 ISO


I evaluated the line thickness readings for the lowest fully resolved row for each of the charts in each chart board image.  The resolution in LPH (lines per picture height) is given by 3888/ line thickness.

This gave the results shown below (the LPH for the corners is shown as a single figure where the readings were the same).

It can be seen from these results that at all aperture settings from f/2 to f/10 the centre resolution is 2990 LPH, while the corner resolution is generally about 2780 LPH, being slightly higher for some corners at f/5-f/6.3 and slightly lower for some corners at f/2 to f/2.8. 

At aperture settings of f/11 and above the centre and corner resolution falls off due to diffraction effects, until at f/22 the centre and corner resolution is 1850 LPH. 

These results show that the Pen-F with this 50mm lens gives very high resolution over a wide aperture range, from f/2 up to and including f/10.

I next conducted a similar series of tests, but using the Pen-F in High Resolution (HR) mode.

Continue to Resolution of the Pen-F with the 50mm f/2 Macro with Aperture in HR Mode

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