Here's some advice on using the ZS40. Most of it will work with the ZS50 and similar cameras such as the DMC-LF1.
Turn on Intelligent Resolution (i.Resolution). It seems to make the pictures a little sharper.
Set the picture size to 12 megapixels rather than its normal 18 megapixels. Besides the smaller files, you get a slightly longer zoom range. The image quality for both file sizes is about the same. (This is mainly for the ZS40 and other cameras with bloated pixel counts.)
Use the viewfinder. It isolates the image. It blocks out daylight. It's always the same (unlike the screen on the back of the camera, which is hard to judge in varying ambient light). You need it for the longer focal lengths. It will help to steady the camera for long exposures. You'll take better pictures.
Calibrate the viewfinder. Take a picture with a wide range of tones and colors. Keep a copy on the camera and copy it to the computer. Now compare the image in the viewfinder with the image on your computer's monitor. Go to the camera's setup menu and adjust the viewfinder image until it matches the computer monitor.
Set the front ring (the one around the lens) for exposure correction.
This will make it easy to change the exposure. You'll need it for what follows.
The ZS40 tends to overexpose, and most people complain about pictures that are overexposed or washed out. You may even hear of "blown highlights" and lost highlight detail. You can fix some of this by shooting in raw format, but a better answer is to get the right exposure when you shoot the picture.
Next time you take a picture, use the viewfinder and study the scene carefully, not just for framing and composition, but for exposure as well. Look for the brightest area of the picture where you want to have detail in the finished picture. Now try moving the ring around the lens, increasing or decreasing the exposure until that area looks right. Chances are that decreasing the exposure (darker) is what you're looking for.
Experiment with this until you learn how use some underexposure to move things into a correct, balanced look. This will take some practice as the viewfinder might look too dark, but the review image that you see after you shoot will look correct. Don't be afraid to shoot lots of pictures to get the feel for this. It's free.
This is just a brief outline. I'll have more to say about getting the right exposure in future articles.
Retrospective note: Looking back, I find lots of reasons to like the DMC-ZS40. Viewfinder, good image quality, and long zoom lens says it all. It's not as refined as the DMC-LF1, which has better image quality and more camera-like features (like a sharp, fast lens and a real black and white mode). But it sure is a lot of fun to shoot with.
So I'll be shooting with the ZS40 in situations where I'll be needing its impressively long reach. Otherwise, I'll be using the LF1.
Some technical notes: All of the pictures were shot with my Panasonic DMC-ZS40. The post processing was done with LightZone-3.
Closing note: I now have a DMC-FZ50, the newest model in this series. It has an improved viewfinder and they've dropped the megapixel count from 18 to 12.
Sounds good, right? Unfortunately, I was not able to get the same image quality out of the ZS50 as I got from the ZS40. So I still recommend the older model, even though the ZS50 looks great on paper.