Noise reduction options

There has been much discussion of Panasonic's noise, and noise reduction; one of the marketing claims for the LX2 is that it offers significantly lower noise than its predecessor despite cramming even more pixels onto a tiny sensor. The LX2 features the same new Venus III processor seen on the recently-reviewed FZ50, and one of the selling points is its advanced noise reduction. Like the LX1, the new camera has the option to adjust the amount of noise reduction (low, standard, high), though as our tests show these should perhaps be renamed 'high, higher, highest' - and the only way to reduce NR any further is to shoot raw and process yourself.

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 a new test the crops below show the effect of the three levels of noise reduction on such texture (fur in this case) as you move up the ISO range.

ISO 100 Low NR ISO 100 Standard NR ISO 100 High NR
ISO 200 Low NR ISO 200 Standard NR ISO 200 High NR
ISO 400 Low NR ISO 400 Standard NR ISO 400 High NR
ISO 800 Low NR ISO 800 Standard NR ISO 800 High NR
ISO 1600 Low NR ISO 1600 Standard NR ISO 1600 High NR

Just as we saw with the FZ50, Panasonic's in-camera noise reduction is way too high at anything over ISO 100 (even then there is a slight advantage to shooting at the low NR setting). Particularly disturbing is the ISO 200 result, which has an almost unbelievably destructive 'watercolor' appearance. Basically ISO 200 is perfectly usable if - and only if - you turn the NR to low or shoot raw, and ISO 400 up is severly lacking in low contrast detail. Panasonic's claims for lower noise (over the LX1) are certainly true, but what they should have mentioned is that this is achieved through higher noise reduction, nothing else. These crops also show the other side of such heavy chroma sub sampling; significantly reduced saturation at ISO 400+.