Readers Write: The Wrong TZ10 Sensor?

One of our readers contacted us with this query about the Panasonic TZ10:

Hello DigitalVersus, I'm writing to you as I think I've found a mistake in your test of the Panasonic TZ10, which has a 1/2.33" sensor (according to the manufacturer's website) and not a 1/2.5" sensor as quoted in the tech specs on your site! Plus, when you compare the TZ10 with the Canon SX210 IS [...], according to the photos in your face-off, colour reproduction in the SX210 IS is much better than in the TZ10, which is the opposite of what I've seen on another review site. Thanks in advance.

First of all let's look at the sensor size. It's actually not the first time a reader has pointed this discrepancy out to us, as we had the same problem with the Panasonic TZ7. The TZ7 was the first consumer digital camera to feature a 'multi-aspect' sensor, which is actually larger than the size of the final picture taken by the camera.

You're right that the TZ10 does feature a 14-Megapixel sensor which is 1/2.33" in size, and its native resolution is 4320 x 3240 pixels. However, the sensor is never actually used at this resolution (unlike other cameras with similar sensors, like the Canon SX210). To take a 4:3-format picture, the TZ10 effectively chops out a rectangle measuring 4000 x 3000 pixels from its larger sensor. Some of the extra pixels are used for taking 16:9-format pictures, which use the full width of the sensor, but which are only 2432 pixels high (see right).

The main advantage is that it the diagonal image size remains constant, at around 7.2 mm, which is equivalent to a 1/2.5" sensor. Plus, as the field of view doesn't change, the 25 mm wide angle can be used for taking photos with an aspect ratio of either 16:9 or 4:3. The larger sensor also helps limit the loss in resolution often associated with changing to the wider 16:9 picture format. The TZ10 takes 16:9 pictures in a resolution of 10.5 Megapixels, but without the larger sensor, the camera would effectively have to chop off the top and bottom of a picture of the same with, reducing the resolution to 9 Megapixels.

In our tech specs, we decided it was more important to give the maximum resolution that can actually be obtained with the camera and the size of the zone actually used on the sensor. For TZ10, that's 12 Megapixels and 1/2.5". Plus, the size of the actual section of the sensor used effectively determines what type of lens the camera needs, which in turn determines the final image captured. So although in reality the camera uses a bigger sensor (or two smaller ones, as in some rare models made in the days when larger sensors were too expensive), in the end, that has no real importance since the whole surface area isn't used.

For your question regarding colour reproduction, we'd rather just say that the two cameras are different, rather than saying one is better than the other. Canon cameras are known for capturing warmer colours, and you might notice a very slight yellow tinge the whites as a result. The TZ10 is more neutral, and a little on the cool side. This means that with our test scene, the Canon camera gives a more striking result on the coloured fan, whereas the Panasonic camera saturates colours on the map. It's more a question of taste than any kind of objective measurement. In fact, a camera that took perfect pictures in a strictly mathematical sense would take slightly dull-looking pictures that wouldn't be as pleasing to the eye.

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