While this lens, like every non-professional zoom on the market, does not deliver peak performance at the long end, with good technique it is definitely very possible to get sharp results from this lens at the full 600mm equivalent extension. And while Panasonic lenses autofocus as you would expect on OM cameras, they are tuned for Panasonic's own DFD contrast detect AF system – and some notable examples (such as the Panasonic 20mm f/1.7) focus incredibly slowly on non-Panasonic bodies. Overall, we think that OM System lenses are just that bit snappier on OM System cameras. Etymology: Middle English rumour, from Anglo-French, from Latin rumor clamor, gossip; akin to Old English rēon to lament, Sanskrit rauti he roars DOnt think Panasonic Lens OS works on Olympus Bodies. I have the 100-300MM and have owned the Oly, Hands down the Panasonic is better, Oly is slow in everything and terrible at 300MM. I have not used the Oly lens but for me it is the dual stabilization that I like about the Panasonic lens. After using it on my G85 with the dual IS I would not use it on my Oly bodies, the dual IS makes the picture taking so much easier.

How does this matter to sharpness tests? I'm pretty sure neither lens had improvements over sharpness, because the design is almost the same. OTOH, the panny 100-300 is weather-sealed and has IS and combined with a panasonic body, the IS is great. aperture is a tad faster and helps to keep the ISO lower. P.S.-If you look at my link below you will find most of the wildlife shots and some landscapes were made with the Panasonic 100-300ii lens on my G9 body. First of all, the 75-300 should not be softer at 150 than the 40-150. If it consistently is, then something is amiss.The most obvious use is the wildlife. But in travel photography, things are often just far away and you cannot get any further. At times even we feel the need of a telephoto lens while traveling. Of course, we do not want to invest in something expensive. Olympus 75-300 looks like a good one even with its shortcomings. Anyways it seems value for money. We are currently using Nikon and have a Sigma Telephoto lens. And to be honest, we are somehow not happy with its performance. The idea comes from target rifles, where the heavier target rifle is easier to shoot accurately, than a lighter sport rifle. The weight of the target rifle helping to dampen out the natural body wobble. i have the 45-150 panny and at 150, either of the 75-300 or 100-300 is sharper at 150. at least my copies are that way. Yeah that's what I was thinking too. Now I just need to figure out how much I value weathersealing...

Otherwise I think both of these lenses have enough sample variation, that it's hard to say which is sharper. I am new to the 3/4 system so I have no idea of the internal working parts on this lens. What parts could come loose in manufacturing. Do i have a lemon?

In the end I found 300mm too hard to handhold and f/6.7 too slow so I moved on to the 40-150 f/2.8. Well, both old and new versions might have some variance, but for me the new one was significantly better, especially in high contrast scenarios. Consequently I sold my old 75-300, of course at a huge loss. I want to buy a telephoto lens for landscape photography, to reach more then what my trusty 35-100mm can offer. But i hesitate a lot between the Olympus 75-300mm II and the Panasonic 100-300mm II. Bokeh is a word used for the out-of-focus areas of a photograph, and is usually described in qualitative terms, such as smooth / creamy / harsh etc. In the M.ZUIKO Digital 75-300mm f/4.8-6.7 ED, Olympus employed an iris diaphragm with 7 rounded blades, which has resulted in a pretty nice bokeh for a zoom lens, at least in our opinion. However, recognising that bokeh evaluation is subjective, we have provided a few examples for your perusal. I recently got the OM-D E-M1 with the fabulous 12-40mm F2,8. This is an extremely good combination. This lens can focus to 20cm for near field pictures. I will keep my E-M5 and use it mainly for the Panasonic 45-150mm or the extremely good Zuiko 60mm F2,8 macro. I need at least two bodies as it’s very fiddly to change lenses when you are outside. I’ll see if I’ll get use of the longer reach 75-300mm.