This is a remarkable lens in a remarkable camera.
First, all other superzooms are scaled down SLR designs, which are just too bulky to slide into your pocket. The Panasonic TZ4 isn't.
It's fatter than the average digital compact, true, but it's still slim enough to fit in a pocket. It's a genuine go-anywhere just-in-case camera.
An impressive lens
Second, with a couple of exceptions, other superzooms concentrate the extra focal length at the telephoto end of the scale. You can fill the frame with a roe deer in the next county, but you still can't squeeze in the whole family at a birthday party.
The TZ4's lens, though, offers extra focal length at both ends of the scale with a 28-280mm equivalent focal range. Not only can you shoot long-range telephoto shots, but wide-angle images, too.
Third, most superzooms bring optical compromises which include increased distortion, poor sharpness at maximum focal range and increased chromatic aberration. The TZ4's lens suffers from none of these.
Barrel distortion at the wide-angle end isn't just well suppressed, it's difficult to actually find any examples of it. And where other cameras produce those characteristic magenta fringes at the edges of the frame and around silhouettes, the TZ4 doesn't.
Limited image quality
There are limits to the image quality, of course. Like just about all compacts, the Panasonic uses a 1/2.5-inch sensor, which is around half the size of your little fingernail. Today, it's the size of the sensor, which limits the camera's definition, not megapixels, and all compacts are pretty much in the same boat.
Having said that, a top lens and image-processing system will wring out the best possible quality, and the TZ4 has both. Its definition is as good as you could ever expect, and as long as you stick to low ISOs it's possible to produce very high-quality images that can stand considerable enlargement.
It does go right up to ISO 1600 (ISO 6400 in High Sensitivity mode) but, to be honest, past ISO 400, it's not whether the camera can do it that's the question, but whether you can tolerate the loss in image quality.
Again, though, this isn't a flaw in the Panasonic - it's a characteristic of small sensors generally.
Some handy features
The TZ4 has other interesting features. As well as shooting in the usual 4:3 aspect ratio of digital compacts, it can switch to the 3:2 ratio of a digital SLR or the 16:9 ratio of a widescreen TV.
It comes with a selection of 'scene' modes but takes them a stage further with an Intelligent Auto mode, which chooses the appropriate scene mode automatically, based on what's in front of the camera. It works pretty well, too, though for those who prefer to do without the smoke and mirrors of scene modes, there's a regular program auto mode, too.
It has a quick and accurate face detection system too.
Panasonic's tempting alternative
There is just one thing, though. The TZ4 has a stablemate, the TZ5, which is like a kind of deluxe version.
The TZ5 costs more, of course, but offers 9-million pixels instead of 8, a much better 3-inch 460,000-dot LCD and can shoot high-res movies for playback on the latest HD TVs.
The TZ4 is an excellent camera at an excellent price, but you may always wonder whether you shouldn't have spent just a little more and gone for the TZ5 instead.