I feel that the only way to really get to know a lens is to use it for a decent time, in a variety of circumstances. There are simply too many variables and combinations at play.
To purchase, you will likely read a review or two or act on a good recommendation from a user, but that is only step one of a long process. Sad to say, you need to commit at some point and deal with that choice, but my recommendation is to save judgement until some time has passed.
A lens is as good as the best image it can take and how consistently it achieves that.
Overall, my Olympus (and occasional Panasonic) lenses have been excellent, some even magnificent.
I will list them below, not in any order other than which comes to mind first, with a severely potted over view, as I have written plenty on the subject and to be honest, my images should be the gauge, not my words.
40-150 Pro. Sharp, contrasty, possibly brighter than the f2.8 aperture suggests and tough. Jittery Bokeh some times with busy backgrounds, but otherwise near perfect. This lens has forced bag compromises on me, which are fully worth it. It also loves the TC 1.4.
12-40 Pro. A workhorse, reliable all the way out to the edges, fast to focus and offering pleasant and fast transition Bokeh. Only issue is a slight stiffness “lump” that has developed in the zoom around 18mm. This lens is often used for video now.
40-150 kit. Simply the best value lens I have. What a giant killer. The images are “crunchy” sharp, with decent colour. All other specs are great if you ignore the super light build and stiff zoom, but it’s still going and a travel/street favourite. Handily, the lens has a similar character filled look to it’s files to the 17/45 lens combo I use for street.
75-300. This is a sentimental favourite, left neglected as a result of too much choice. If I have a summer sports event, something low key like younger age group events or maybe just need a long lens for un-foreseen circumstance, then I could certainly do worse. It has rich colour, smooth Bokeh and good sharpness. I actually prefer this lens to the 40-150 Pro in strong light thanks to it’s pleasant contrast and it looks as sharp at matching zoom settings. The only issue is written on the barrel, slow maximum apertures, but I knew that going in.
14-42 EZ. This one is a decent video lens offering electronic zoom. Of the three “transitions” (zoom, focus shift, movement), I think zooming is the most obvious and clumsy, so should be avoided, but I have the option. In other respects it is likely my weakest lens overall, but that speaks well of the others as it is not bad by any means.
8-18 Leica. The ringer in the group. I have always liked this lens over the less practical Olympus 7-14 Pro. Focus can be a little twitchy on Oly cameras (although touch screen AF on the EM1’s seems faultless), but otherwise it is a strong performer. The range also sits perfectly with MS-1 stabilising, which crops a little, making it roughly a 28-50 FF equivalent. Only issue is the easily switched MF switch on the side.
17 f1.8. Once my go to lens for street/travel, this one sees little use at the moment, although recently, it has meshed nicely with an old EM5 as a good low light close-in lens. Sharp enough, small, fast and boasting “elongated” Bokeh transition, this is a great lens when focussing is a little hit and miss due to shallow depth or manual focus limitations. Biggest fault is a “ticking” sound in C-AF for video (solved by recording sound separately).
25 f1.8. A workhorse with the same “big” look the 75mm has. Best Bokeh of the shorter lenses, truly beautiful and strong looking. I love this lens for tight portraits with messy backgrounds. Closer to a 45mm in reality, this lens is a keeper.
45 f1.8. I have 2 of these and intend to keep them. The 25/75 combo have a “larger format than M43” smooth and effortlessly sharp look, while the 45 and 17 have a more realistic, character filled look, with tons of micro contrast.
75 f1.8. The Bokeh king, this is likely the most “perfect” lens I have owned. It flattens subjects slightly and genuinely “cuts out” portrait subjects with tremendous sharpness and rich colour. Only complaint is it is a little too perfect and predictable. Biggest issue is the cold metal barrel tends to fog the rear element when mounted on a hot camera.
300 f4. What a blessing it is to have this lens. The look of it’s files is quite different to the 40-150 Pro. The zoom seems lighter and brighter in low light with more obvious, contrast based sharpness, where the 300 has more delicate, very fine detail sharpness and better high contrast control. This lens loves tight cropping and strong light, while the zoom loves low light. Perfect.
The 17 in it’s natural habitat. This lens has a unique character and many very useful characteristics for street shooting.
Snap taken with the relatively weak 14-42 with an EM10 mk2.