I hope it's ok to jump in with a question...
Not many people out there who own both, so it would be nice to get some impressions from you using these for bird photography? E.g. How does the autofocus performance compare for birds in flight or fast moving warblers? Does the Panasonic have enough light in dark tropical forests?
I'm also thinking a bit to moving up from a bridge cam, and naturally the Panasonic with its better portability and lower price is the most attractive option for an upgrade. I just wonder if the the step up is big enough, or if I soon would want the Oly or even DSLR...
Thanks for your thoughts! Florian
I have not done formal tests, so not sure how useful my comments will be.
I probably would have just bought the Panasonic/Leica zoom, but I wound up with both because I was going on a trip and only the Olympus was available at the time. I had never used a prime telephoto lens before, and decided after the trip that without a zoom I was going to be missing some shots in key situations. My practice now is to generally stick with the Olympus, but switch to the zoom when I am viewing wildlife from a vehicle (e.g. boat or car), or when I expect animals to be close, or large animals to be at medium-range, such as around a lodge where they are accustomed to people. The specs of the Olympus with teleconverter also make it slightly preferable when you are at a distance--40mm more reach and slightly wider aperture.
My impression is that the image quality between the two is quite close. I think in ideal conditions the Olympus is going to give you more of a “wow factor” in terms of being tack sharp and contrasty, but I've been very happy with the results from the Panasonic as well.
As for focusing, I seem to have a problem with getting the Olympus to autofocus when my camera wakes up from sleep mode, e.g. sometimes I have to resort to firing off a shot before it will focus. Not sure if this is a problem with my camera or my settings or the lens. I have not noticed a big difference in autofocus between the two lenses otherwise, except that, obviously, birds in flight are easier to acquire in the viewfinder if you can be zoomed out first. I seem to have mis-focus problems with both lenses similar to what I had with the 100-300 mm Panasonic, which was my previous zoom lens. But I find these easier to correct on the Olympus because I can switch to manual focus simply by sliding the focus ring on the camera forward; the zoom has a switch near the base of the lens which is harder to find when you are looking at a bird.
As for speed, I typically use the teleconverter with the Olympus, so it is at F5.6. (I find the extra reach more beneficial than a somewhat wider aperture). Inside rainforest, I try to take advantage of the dual image stabilization by switching to much lower shutter speeds than I used to use, even down to 1/30. I find shooting with burst mode you can usually get a decent shot of even a fast moving bird at slower shutter speeds, since almost all birds pause briefly when moving. I take a similar approach with the Panasonic, but do not push the shutter speed quite so low because I do not have the dual image stabilization on my camera for that lens. If I go on night walks where I anticipate taking photos of spotlighted animals, I will remove the teleconverter and take advantage of the faster lens.
Hope this helps.