Occupying an interesting middle ground between the company's LX100 enthusiast compact and FZ1000 megazoom, the Panasonic Lumix ZS100 offers a general-purpose compromise among image quality, zoom and size that adds up to a highly recommendable camera for families, travelers and even hobbyists who get frustrated with the short lenses in most enthusiast compacts.
Part of Panasonic's "travel zoom" series of compacts -- hence its alternate names TZ100 in the UK and TZ110 in Australia -- the ZS100 goes head-to-head with the Sony Cyber-shot RX100 IV. That's a pretty good deal for its price, as well: $700, £550 and AU$1,000.
The ZS100 incorporates the same 1-inch sensor as the excellent FZ1000, but the lens is a shorter and slower 10x lens -- 25-250mm f2.8-5.9 -- compared to the FZ1000's big 16x f2.8 lens. That allows Panasonic to keep it small, making it the longest-zoom compact in the 1-inch class. There are some trade-offs to get that zoom, however; its lens isn't that great, and because it has a greater area to focus over it does more slowly than competitors.
Photo and video quality
Though it's not quite up to the standard of the best cameras with 1-inch sensors, I think most people will be perfectly happy with the photo and video of the ZS100, which ranges from very good to excellent. In auto mode the photos tend to come out darker than in manual or priority modes which results in very dense shadows, but for the most part it delivers.
A lot depends upon how far you're zoomed in and what aperture is set in addition to the typical factor of the ISO sensitivity setting. The lens doesn't seem to be particularly sharp in general, with more than usual distortion around the edges. And at the longer zoom and narrow apertures -- essentially from f4 to f8 -- photos get a lot softer. You reach those apertures very fast; it reaches f4.1 by the time you hit 50mm. And that's the tradeoff for the benefits of a 10x zoom. As long as you're not scrutinizing the photos at full size, though, I think you'll find it worth the slight sharpness sacrifice.
There's a Diffraction Compensation setting which theoretically counteracts the softening effects of the narrowed aperture, but since the only choices are auto or off, it's impossible to tell whether it's actually doing anything.
In bright light JPEGs look very good; as the light dims, they start to look very smeary. Keep in mind that in low light (i.e., at high ISO sensitivities) for any camera, out-of-focus areas start to degrade a lot faster than those in focus. So the ZS100's naturally soft photos start to show artifacts in low light faster than ones shot with a better lens. Color and exposure look pleasing, though.
You can get better results in low light by shooting raw -- in some cases, without even doing anything to the file other than opening it and saving as a JPEG. That's because raw avoids Panasonic's aggressive processing.
Its 4K video is excellent for point-and-shoot purposes, though you do see visual noise in low light and slight movements of the camera produce wobble, which is pretty typical.