Noise, resolution and sensitivity
These images show 72ppi (100% on a computer screen) sections
of images of a resolution chart, captured using the fixed Elmarit 24mm f/2.8 Asph lens. We show the section of the resolution chart where the camera starts to fail to reproduce the lines separately. The higher the number visible in these images, the better the camera’s detail resolution is at the specified sensitivity setting.
Raw images taken with the Leica X2 show about as much detail as you would expect from a camera with a 16.2-million-pixel sensor. JPEGs, however, are a little underwhelming, only reaching around 24 on our test chart when shooting at ISO 100, which is about what you’d get from a 12-million-pixel sensor.
More detail can be revealed from the DNG raw files, with images taken at ISO 100 reaching almost 28 on our test chart. This is about on a par with most other 16-million-pixel sensors. The DNG raw images sharpen nicely in Adobe Camera Raw, and it is easy to control colour noise as the sensitivity increases.
Noise is relatively well controlled at low ISO sensitivities, but is visible at ISO 1600. At ISO 3200, luminance noise can be seen, despite apparent attempts to smooth it out in JPEG files. At this sensitivity there are only slight signs of chroma noise in shadow areas.
The maximum ISO 6400 and ISO 12,500 settings are actually best avoided as luminance noise is very apparent in each. In fact, at ISO 12,500, it appears that there has been a lot of sharpening and contrast applied to compensate for flat images that have had luminance noise reduction applied. The overall effect is not very flattering.
I would recommend that ISO 3200 be the maximum setting that most photographers should consider using.
When converting raw files at ISO 6400, it is possible to reduce colour noise almost completely, but to keep detail some luminance noise must be retained.
The resulting images are just about usable, if not ideal. Even when shooting raw, the maximum ISO 12,500 seems a step too far, and it is difficult to find a suitable compromise between noise and resolution detail.
The best option is to convert these images to black & white and add a hint of speckled grain effect, to make them appear like a push-processed film.
Image: Taken at ISO 12,500, raw images have a lot of luminance and chroma noise. This is reduced in JPEG files, but at the expense of detail
