Instruction: Generate an answer to the question by utilizing the information contained in the document.

Input:
Question: How good are the images produced in low light from an 18mp sensor?
Document: In low light, not so much. It's not that it performs poorly, it just performs like a small sensor digital camera with a relatively slow lens should perform. Flash pictures are better than on previous models, but if you try to take advantage of the zoom in low light, the flash won't be much help at that distance. (Flash photos are much better at the short end of the zoom range.)
I use this camera for travel and made over a thousand pictures on a recent trip. It was very easy to switch from IA (fully automatic) to scene mode, and quickly turning the auto flash on and off. The HDR effect worked automatically and really improved a lot of backlit scenes. Low light picture came out well, although there will always be more noise with a smaller sensor compared to a larger sensor.
The tiny CMOS sensor has the light gathering pixels on one side and control transistors on the other, unlike a CCD sensor. Why 18MP, only because the stupid MP race has yet to end, more tiny pixels is not better, just adds digital noise. Don't expect miracles, this camera is more about world class memories than world class images.ADJUSTMENT RINGS:The two adjustment rings, one around the lens and another around the 4-way controller are amazingly handy and user configurable.
Very long zoom on a small sensor camera normally means not so good picture quality. The ZS40 is not perfect: Pictures taken with ISO above 400 will show a lot of artifacts and the lens is not fast at all. The IOS, however, is top notch and will allow pictures taken at very low speed without problem. What I really like on this camera, however, is how reach in features it is. WIFI and GPS are very helpful when you travel.
It can't handle low-light conditions at all well. The WiFi features sound good on paper but doesn't work nearly as well as it needs to. Setting up its remote feature on a cell phone is downright painful. Automatic uploading of shots seems useless.The GPS is quick and sometimes works well but sometimes has no clue where it is beyond lat and long, which is good enough. I can fix it once I'm on my laptop.
Nowhere near as clean and fine as images from the FZ150 (which has 12mp on the same size sensor).
Bought camera for trip to Ireland. Camera worked like a charm. Loved GPS feature even though a little quirky. also loved way camera responded to taking pictues where there was low light and the pnoramic feature. The optical zoom is amazing. In the past, use of the zoom, meant you needed a tripod to stop shake.
Nice and wide to great distance. The image stabilizing works well. Focusing is fast, except at long zoom and very low light (which is typical of this class of cameras). I've seen some reviews complain about the low resolution of the electronic viewfinder (EVF), so I was surprised to find it is much better than I expected - once I used the diopter control to adjust it for my glasses.
I recommend you go into the menu and set the ISO limit to 800 - before letting the computer manipulate it, higher settings may cause photos taken in low light to show noise (freckles of dark spots). The S setting means you to "insist" that the camera use a specific shutter speed but you will allow the computer to choose the aperture (to get the correct exposure) and of course the ISO.
I don't mind that it has its own cable, because I keep the cable in the camera pouch that I bought with the camera. It takes fine low-light shots too. It can take several low-light shots and add them together automatically. The panorama shots are easy and work well. I still haven't tried all of the features and picture modes, so I expect to have even more fun with it. The zoom is incredible, along with motion stabilization. I would say that's the best feature.
Answer: Before I answered you I walked into my dark closet and took a shot. My camera could see better, and clearer, in low light than I could. I cannot say enough good things about this camera. Read the info online at Panasonic.com and you will learn much more than I can say in this reply.