--- type: page title: Film SLR lenses on a Micro Four Thirds camera resource: https://www.mattihartikainen.net/en/articles/film-slr-lenses-on-a-micro-four-thirds-camera canonical: https://www.mattihartikainen.net/en/articles/film-slr-lenses-on-a-micro-four-thirds-camera timestamp: "2026-07-27T21:12:58.047Z" access: public status: published nodeId: f97aac9d-f0ac-469a-aeb7-fcfdbc9c3c26 --- I ran some tests with my old Olympus OM lenses, which can be used with an adapter on my current Olympus OM-D E-M5 body. My aim was to find out how well the lenses draw at different apertures, both in the centre of the frame and at the edges, so that I would have a sense of which apertures are usable in which shooting situations. While doing so I made a surprising discovery in the test shots from some of the older lenses. At the widest apertures the image was frankly poor, because of strong internal reflections and a lack of contrast. Stopping down improved it. With some lenses I find the effect distracting enough that buying an adapter for their sake alone could well end in disappointment. For the resolution test I made a chart 630 mm high. The repeating test pattern is my own modification of an original found on [Erlend Rønnekleiv's site](https://www.eronn.net/camera/test-chart/resolution%20test-chart.jpg). The numbers on the chart give the number of line pairs at that point across the full height of the frame. They are in no way scientifically precise, but they do convey the order of magnitude and they are comparable within this test. The same applies to the charts further down, where the assessment of drawing quality is additionally based on my own visual judgement. ## The test chart ::image[The full test chart, 630 mm high]{#m17614s9x2t4b945dh8sxx460589zpfp} The numbers give line pairs across the height of the frame (LP/PH). The points marked in red are where I took the sample crops, from the centre and from the edge. ### OM 75–150 mm F4 ::image[OM 75–150 mm at 75 mm, F4, centre of frame]{#m177b58e3m0gx76t4v1c6chksx89yxn0} ::image[OM 75–150 mm at 75 mm, F4, edge of frame]{#m173k7s97y6zhsppcp5mqdws1989zwwh} Wide open, reflections degrade the image both in the centre and at the edge. ::image[OM 75–150 mm at 75 mm, F8, centre of frame]{#m174sntre06fvzd1gvkbm0ea7x89z7t0} ::image[OM 75–150 mm at 75 mm, F8, edge of frame]{#m17d6my7vr34jwv1xzz0yn0e4n89ykj3} F8 is where this lens draws best. Stop down further and diffraction begins to eat into the sharpness. At 150 mm my results are almost identical to those above. They are a shame, because the lens is pleasantly small and covers the equivalent of 150–300 mm in 35 mm terms. ### OM 50 mm F1.8 ::image[OM 50 mm at F1.8, centre of frame]{#m173r2g70hvndafy2v2w8rwn0n89yfk4} ::image[OM 50 mm at F1.8, edge of frame]{#m1723y19wrqrqewzs9ecvexdqs89yckt} ::image[OM 50 mm at F8, centre of frame]{#m17dc9d1msacrrhh8r98p2z1h189yafr} ::image[OM 50 mm at F8, edge of frame]{#m17b539rrx0tcaqerqp1mfxyps89z67r} This reasonably fast lens draws quite sharply dead centre at every aperture up to F8. At F11 and F16 the drawing falls off noticeably. Much of the benefit of the speed is lost to the smeared edges that the reflections cause at F1.8 and F2.8. Below are measurements from a few of the old lenses, including the two examples above. The pink bars mark reflections that degrade image quality. The drawing-quality scale: 1.6 = excellent, 1.2 = good, 0.8 = fair, and 0.4 = poor. ### OM 21 mm F3.5 :::bar-chart[OM-System 21 mm F3.5 · 21 mm]{height=320 xLabel=Aperture yLabel="LP/PH × 1000" flagLabel=Reflections} categories = 3.5, 5.6, 8, 11, 16 Centre = 1.42, 1.4, 1.46, 1.46, 1.3 Edge = 0.6!, 0.82!, 1.08!, 1.07, 0.98 ::: ### OM 35–70 mm F3.6 :::bar-chart[OM-System 35–70 mm F3.6 · 35 mm]{height=320 xLabel=Aperture yLabel="LP/PH × 1000" flagLabel=Reflections} categories = 3.6, 5.6, 8, 11, 16, 22 Centre = 1.42, 1.4, 1.46, 1.46, 1.3, 0.88 Edge = 0.6, 0.82, 1.08, 1.07, 0.98, 0.7 ::: :::bar-chart[OM-System 35–70 mm F3.6 · 70 mm]{height=320 xLabel=Aperture yLabel="LP/PH × 1000" flagLabel=Reflections} categories = 3.6, 5.6, 8, 11, 16, 22 Centre = 1.5, 1.66, 1.64, 1.57, 1.37, 0.9 Edge = 1.05, 1.08, 1.43, 1.12, 1.1, 0.86 ::: ### OM 50 mm F1.8 :::bar-chart[OM-System 50 mm F1.8 · 50 mm]{height=320 xLabel=Aperture yLabel="LP/PH × 1000" flagLabel=Reflections} categories = 1.8, 2.8, 4, 5.6, 8, 11, 16 Centre = 1.4, 1.38, 1.48, 1.5, 1.6, 1.55, 1.24 Edge = 1!, 0.97!, 1.15, 1.38, 1.48, 1.48, 1.16 ::: ### OM 75–150 mm F4 :::bar-chart[OM-System 75–150 mm F4 · 75 mm]{height=320 xLabel=Aperture yLabel="LP/PH × 1000" flagLabel=Reflections} categories = 4, 5.6, 8, 11, 16, 22 Centre = 1.18!, 1.33!, 1.5, 1.45, 1.16, 0.9 Edge = 1.05!, 1.15!, 1.24!, 1.27, 1.07, 0.8 ::: :::bar-chart[OM-System 75–150 mm F4 · 150 mm]{height=320 xLabel=Aperture yLabel="LP/PH × 1000" flagLabel=Reflections} categories = 4, 5.6, 8, 11, 16, 22 Centre = 1.24!, 1.33!, 1.5, 1.45, 1.2, 0.9 Edge = 1!, 1.1!, 1.3!, 1.29, 1.1, 0.82 ::: ### Sun 38–90 mm F3.5 :::bar-chart[Sun 38–90 mm F3.5 · 38 mm]{height=320 xLabel=Aperture yLabel="LP/PH × 1000" flagLabel=Reflections} categories = 3.5, 5.6, 8, 11, 16, 22 Centre = 1.38!, 1.6, 1.64, 1.63, 1.4, 1 Edge = 0.68!, 1.1!, 1.58!, 1.56, 1.29, 0.93 ::: :::bar-chart[Sun 38–90 mm F3.5 · 90 mm]{height=320 xLabel=Aperture yLabel="LP/PH × 1000" flagLabel=Reflections} categories = 3.5, 5.6, 8, 11, 16, 22 Centre = 1.16!, 1.16, 1.35, 1.4, 1.13, 0.88 Edge = 0.92!, 1.03!, 1.35, 1.34, 1.14, 0.88 :::