Noise reduction options
We've noted both high noise levels and heavy-handed noise reduction in previous Panasonic cameras. With the LX3, the company said it was aiming to combat noise by not increasing pixel count over the preceding model, instead offering a more modern sensor design and the latest Venus IV image processing engine. It has also given greater control over the noise reduction applied to the images, with five settings (-2 to +2) available.
As can be seen, the noise reduction is pretty consistently applied to both Grays and Chroma. The range of control is also not that great, with the options really representing 'how much we think you should have, plus or minus a little bit, if you insist,' rather than a truly low or high option.
Low contrast detail
The most serious effect of noise reduction is on low contrast fine detail such as hair, fur or foliage. An inevitable side effect of noise removal is that this kind of detail is also blurred or smeared, resulting in a loss of 'texture'. In this test the crops below show the effect of the lowest, highest and standard levels of noise reduction on such texture (hair in this case) as you move up the ISO range.
|ISO 80 NR -2||ISO 80 NR 0||ISO 80 NR +2|
|ISO 100 NR -2||ISO 100 NR 0||ISO 100 NR +2|
|ISO 200 NR -2||ISO 200 NR 0||ISO 200 NR +2|
|ISO 400 NR -2||ISO 400 NR 0||ISO 400 NR +2|
|ISO 800 NR -2||ISO 800 NR 0||ISO 800 NR +2|
|ISO 1600 NR -2||ISO 1600 NR 0||ISO 1600 NR +2|
|ISO 3200 NR -2||ISO 3200 NR 0||ISO 3200 NR +2|
We've criticized Panasonic before for the aggressive nature of the noise reduction that is applied and the LX3's performance suggests that someone within the company also saw it as a problem. The good news is that, even at its highest, +2 setting, noise reduction is not unbearably destructive, though at the ISO 1600 setting you lose what little fine (low-contrast) detail the camera is capturing and still get noise.
The disappointment is that the effects of noise reduction are still visible at the lowest ISO and the lowest NR setting, with homogenous smudges appearing where similarly-colored detail has been smeared together. So although it's an improvement and generally represents a fairly good level of control over the noise/noise reduction balance, we still have concerns about seeing this this much impact on low-contrast detail.