This is an excellent lens. It’s slightly heavier than the basic kit lens (see my other review of the 14-150mm Zuiko lens). While it exhibits very good sharpness in the center, it’s a tad soft at f/4 in the corners. However, at f/5.6 and f/8.0, the lens becomes exceptionally sharp from center to corner. It’s a superb all-around zoom with an equivalent focal length of 28mm to 200mm in full-frame format. I highly recommend this lens for critical photography work (using one lens !).

After a few months owning this lens, it's my favorite to keep on my body. I find it sharp even wide open and I love the colors and detail I get out of it. I also find its size and weight to be just right. I haven't had to shoot in situations where this lens has noted weaknesses so to me its a great lens to bring everywhere for outdoors, travel, and even family portraits.

The testing was done using an Olympus EM-1 II. When mounted on a tripod and using a release cable, no IS, test through the full range at different apertures turned out fairly sharp, with not too much fall-off at the edges.

In A-B comparisons with the Olympus 12-40mm f/2.8 the OM 12-100m f/4.0 fared reasonably well. Shots through comparable ranges, mostly at f/4.0 and f/5.6, again showed them close, with maybe an edge to the 12-40mm. A big difference, though, was when using C-AF&TR mode, the 12-40mm was consistently better. Using
single shot for both gave essentially the same results.

The purported additional IS with the lens/camera combination did not seem to make one iota of difference. The 12-40mm and the 12-100mm seemed identical at lower shutter speeds. Repeated testing under a fairly controlled environment (static target, consistent lighting, etc.) confirmed this.

The 12-100mm seems to have slightly less contrast than the 12-40m.

Final conclusion is the 12-100mm is worth the cost and compares well with the 12-40mm (which I've used for years so am very familiar with), but the 12-100mm requires a little more work to get the same results. Shipping firmware version is 1.4, same as the original Olympus 12-100, which is consistent with this being the same lens, just relabelled with the OM Systems label.



I'd give it a 4.5 if that was possible, compared to a 5.0 I'd give the 12-40mm.

Great focal length and sharp as any OM pro lens

This lens focuses extremely fast and seems somewhat sharper than the 30mm f3.5 lens I have been using, but I haven't done a systematic check. I seems like a very fine lens. It's now my main walk around lens,

You can take this lens anywhere and not need to carry another. Covers everything you'll need. This lens is a little heavier than the 12-60, but for me well worth it. Fun to use and easy. You'll enjoy taking this lens out and the sharpness is top quality.

The OMS 20mm 1.4 lens appeared to be ideal for my indoor event photography before its release. Initial reviews were modest in praise and definitely critical about uncorrected optical flaws. Well, I jumped anyway. A few days ago I used the lens in earnest, and I can say that it is really ideal for my purposes. The focus is fast, silent, and accurate. Wide open sharpness is all I could ask for, especially in the center of the frame. As for corners, at f/1.4, they really don't matter much. When the lens was stopped down a bit, there was nothing to fault for all practical purposes. The rendering is very natural, with sharpness and color saturation being very nice but not overdone. The bokeh is soft and pleasing. A few pictures were slightly low on contrast but setting white and back points in post fixed that easily. Despite the lukewarm reviews, I find the lens to be a very pleasant addition to my kit. If you go by real-world results, this should be a worthy purchase.

Perfect fit to the EM 5, great all purpose prime.

The OM System 20mm f/1.4 Pro is often criticized in online fora for the large amount of purple fringing present if the sun is in the frame at f/1.4. And, in fact, this amount of purple fringing is very hard to get rid of in post processing and this is the Achilles heal of this lens. The fix is very easy; stop down to f/4 if the sun is in the frame. That's it. Problem solved. At f/4, the purple fringing is totally gone. Period. End of discussion.

I would suppose that the designers of this lens had to make a choice in order to get the lens to be this compact. The choice was to allow the extensive chromatic aberration with the lens wide open in extreem contrast situations.

So, I accept this Achilles heal as a minor flaw in the 20mm f/1.4 lens (with it's easy fix) and absolutely rejoice in every other attribute of this lens, and there are many.