I have been using a Panasonic LUMIX FZ100 for nearly two years (here are some sample field shots) and just recently upgraded to an FZ150. The FZ150 allegedly addresses a number of shortcomings of the FZ100. I use the camera almost exclusively for bird watching; both for documentation of birds I see and as a substitute for carrying a spotting scope. I've actually found that having a super zoom camera has radically changed my bird watching hobby ... for example, sometimes I see things in the photos that I did not see in the field, leading me on occasion to correct identifications.
Reading the reviews, I was expecting the FZ150 to be better than the FZ100 in all situations. After an initial evaluation, I would not say that the differences are that obvious. However, my usage of the camera is pretty specialized: I am almost always at full enhanced optical zoom (so 38X for these cameras), and then I am usually cropping some 10% piece out of the resulting image that contains what I am actually interested in. Plus the lighting is almost invariably undesirable ... I can think of 2 birds in the last few years where the lighting was bright and behind me. So my usage is not typical. I'm putting out this Web page to show comparison shots for conditions that are representative of the way I use the camera.
There are some other early impressions to note. One is that the auto-focus seems faster on the FZ150, which would be a plus. The USB connector at the camera end has a smaller, inferior plug on the FZ150 and the cord is a foot shorter; definitely a negative. The FZ150 also feels lighter, but the difference only seems to be a couple of ounces.
Here are some comparison images, cropped the way I would normally do it. Both cameras on tripods in "Intelligent Automatic" mode, with me trying to press both shutters at more or less the same instant. The FZ150 has a 12MP array and the FZ100 has a 14MP one ... I've tried visually to crop the images to the same field-of-view, without worrying about how many pixels are in the images.
Two-inch high bit of an ant moat for a hummingbird feeder, from 9 feet away, cropped out of a 38X image. In this case, the FZ100 is noticeably sharper. If you zoom in further, the farther off bit of the metal ring has a better defined edge (less noise) in the FZ150 image, but clearly the overall focus is better in the FZ100 case.
A Gray Catbird from about 25 feet, cropped out of 10X images. The Catbird and the foreground Holly leaves are clearly sharper in the FZ150 shot. Worth noting that I have another pair where the FZ150 did not focus as well and the difference is not as striking.
Same bird, but just the head cropped out of 38X images. Subjectively I think the FZ150 image looks better, but it is also more contrasty, so not completely apples-to-apples for sharpness and detail. Seems like the FZ150 is preserving edge detail a little better than the FZ100 (look at the rictal bristles, for example).
Ginkgo branch, cropped from 38X images at about 35 feet. This demonstrated the autofocus algorithm differences. The FZ150 immediately locked onto this tip. The FZ100 was focusing on the background ... I had to go to a custom mode I have with a very small focus area, lock-in and then switch back to Intelligent Auto mode to get it to focus on this. Not much difference in the images I would say.
Same Ginkgo images, but cropped way in to a little piece of the branch. I think this really shows the changes in some of the image processing algorithms. The FZ150 seems to have more noise smoothing but also sharper light-dark edges compared with the FZ100 (so some sort of more aggressive adaptive filtering). I can't say which is better, but they are different.
Interesting results. I think that the Catbird images clearly favor the FZ150, but the others are not significantly different or may even demonstrate better image focus on the part of the FZ100. If I had to generalize with this sparse data set, I'd say that the FZ100 is as good or better than the FZ150 for distances under 10 feet and that FZ150 focuses more quickly and is somewhat sharper for objects over 20 feet away. Other aspects, like autofocus speed, may more decisively favor the FZ150, but that will require field usage to really evaluate.