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>>>>>>>>>> PROCESSING / EQUIPMENT
The processing fits in both. High-quality plastic with metal bayonet. Since there are little to complain about. When Oly 25mm I find the internal focusing better, because I like to use a Gummigeli or various filters. When Pana 20mm the lens moved during focusing and has also some play, which manifests itself in very slight rattle when you shake the lens.
The focus ring is 25mm higher at the Oly and turns smooth. The 20mm of Pana something goes taut.
Total me processing the Oly has addressed 25mm longer.
Finally this is also a lens hood. The can be screwed for the transport in the reverse position, even though the whole then looks as if a Pils grow on the camera. I use anyway prefer a Gummigeli - does not look stylish, but is very convenient as you can leave it forever and must simply fold out for use. I would highly recommend the B + W 900 Gummigeli who cares for it.
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>>>>>>>>>>>> SHARPNESS
In the center the Pana 20mm a tad sharper than all stops. The Oly 25mm loses it to the edge barely focus. On the contrary, the Pana, which is towards the edge considerably softer. From about f / 4.0 are then both at the edge about the same, while the Pana in the image center but remains slightly sharper.
Overall, the Oly 25mm is very sharp, perhaps even a bit sharper than the Oly 45mm. The sharpness of the image center is just simply the strength of Pana 20mm.
As virtually all MFT lenses also Oly 25mm is absolutely open aperture fit again. Can dim the sharpness gain by one highest seen at high magnification or printing poster-sized images on the computer.
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>>>>>>>>>> Chromatic aberration
When Oly 25mm I could almost no CAs make, if at all then only in the far corner at maximum aperture. But they are as good as invisible.
When Pana 20mm CAs are slightly better identify. A real problem is they do not provide but also here. They are to be discovered throughout the aperture range of the image, but overall very inconspicuous.
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>>>>>>>>>>> Vignetting
When Oly 25mm there also here not to report back slightly. A Randabdunklung is hardly recognizable even at maximum aperture in the extreme corners.
The Pana 20mm clearly stronger vignetting and not just in the extreme corners. At maximum aperture of the screen is significantly darker than the center. Easy to fade to f / 2.8, and all will look much better. Randabdunklungen are then most still make out in the extreme corners with the naked eye.
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>>>>>>>>> DISTORTION
Distortion is corrected in default MFT lenses, so which is also no problem with both lenses. An evaluation of uncorrected RAW files I will make in the coming days.
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>>>>>>>>> AUTOFOCUS
The AF of Oly 25mm is quickly and quietly of the Pana 20mm loud and slow.
However, the AF speed of the two with little or hardly any light almost equally, but what surprises me. The Pana has the focus point as fast or slow as found Oly. But as soon as something more light comes into play is the Oly 25mm noticeably faster.
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>>>>>>>>>>> CONCLUSION
Overall, Olympus has made little wrong with the M.Zuiko 25m f / 1.8. The Panasonic 20mm f / 1.7 is designed for greater contrast and sharper in the center, but all the other disciplines, the Oly 25mm, more or less clearly, to decide for themselves. How will it look like in daily use be to test yet. It is not always everything is describable with the conventional optical parameters. So many swear, despite apparently only average optical power, the M.Zuiko 17mm f / 1.8, because it has something in the true things contrasts and colors.
Priced the Oly 25mm is probably classify the long term at the level of Pana 20mm, since both have a MSRP of 399 EUR. This makes the Oly to a pretty good game. The Pana has the advantage that it has long been on the market and the second-hand market is well stocked. 230 EUR 250 EUR you have to lie down for a used currently Pana.
A recommendation from me it does not, the choice must at all make for themselves. Here again is a summary:
Advantages Panasonic 20mm f / 1.7:
+ Small and compact
+ Better sharpness in the center
+ Currently still cheaper
Benefits M.Zuiko 25mm f / 1.8:
+ Better sharpness at maximum aperture at the image edge
+ Less vignetting at maximum aperture
+ CA's slightly better korregiert
+ Internal Focusing
+ Faster and quieter AF
