Even More Resolution
There are two versions of the D800, the second being designated the D800E. This is exactly the same camera in all but one area, namely the arrangement of the low pass filters (LPFs) located in front of the image sensor.
The standard camera employs two LPFs separated by something called a ‘wave plate’ which is mated with an IR filter. LPFs are designed to reduce aliasing patterns – which happen when the frequency of a pattern in the subject coincides with that of the pixel pitch – and manifest themselves as a moiré effect or false colours. They do this by slightly shifting the image – by no more than one pixel – in the horizontal and vertical directions which results in four ‘copies’ that are slightly offset. In effect, then, the image on the sensor is ever so slightly blurred which, with subjects in which no patterns or textures occur, represents an unnecessary loss of resolution.
On the D800, the first LPF shifts the image horizontally and the second shifts it vertically. The wave plate converts the polarised light into circularly polarised light and obviously the IR filter removes light in the infrared wavelengths. On the D800E, the first LPF shifts the image vertically, there isn’t a wave plate and the second LPF combines the image vertically. This means that, at the resolution-matching pattern frequency, the two LPFs effectively cancel each other out, but with all other patterns some anti-aliasing is still happening (unlike if the low pass filter has been removed completely). However, this isn’t at the expense of sharpness.Nikon says the D800E is aimed at photographers “...who can control light, distance and their subjects to the degree where they can mitigate the occurrence of moiré”, but it’s probably debatable whether the majority of non-professional users will find the standard camera doesn’t already deliver sufficient sharpness and definition. At the camera’s launch in Japan, Nikon suggested that the D800/D800E production split would be 98/2 percent, so the ‘E’ could well stand for ‘elusive’.
Not surprisingly, the D800 delivers unsurpassed levels of detailing and definition, but it also performs exceedingly well in the terms of the dynamic range (even without ADL processing) and noise levels. Noise is essentially negligible up to ISO 1600 and still comparatively low at ISO 3200 and 6400. The camera’s ability to crisply resolve the finest of details quickly highlights any deficiencies in camera technique… in terms of lens quality, focusing accuracy, aperture selection and, very critically, the avoidance of camera shake.
Files And Management
Due to the smaller pixel size, the sensor’s sensitivity range is a more sober ISO 100 to 6400 with a two-stop ‘push’ to ISO 25,600 and a one-stop ‘pull’ to ISO 50. However, while it doesn’t offer the stratospheric sensitivity settings of the EOS 5D III or the D4, the ‘reality test’ suggests that a useable ISO 6400 at 36 MP is going to trump a struggling ISO 102,400 which compromises the definition and sharpness of a lower resolution sensor.
The D800’s sensor is mated with a dedicated version of Nikon’s latest ‘Expeed 3’ processor which has to undertake some serious number-crunching, especially with the camera’s on-the-fly image processing functions such as the on-the-fly ‘Advanced D-Lighting’ and noise reduction corrections. Analog-to-digital conversion is performed at 14-bits per RGB channel with 16-bit image processing which is designed to help maximise the dynamic range.
As with the D4, images can be captured as JPEG, RAW, TIFF or RAW+JPEG. The JPEGs and TIFFs are available in three sizes – large at 36.1 MP, medium at 20.3 MP and small which is still at a size of nine megapixels. Three levels of JPEG compression are available, while the RAW files can be captured at 12-bits or 14-bits and lossless compressed, compressed or uncompressed. RAW+JPEG capture can be configured to any of the RAW options plus a large JPEG at one of the three compression levels. There’s also a choice of frame formats, namely full-size (which Nikon designates ‘FX’), ‘APS-C’ size (‘DX’), a 5:4 aspect ratio (a 30x24 mm image area) and 1.2x (30x20 mm). The D800 can be set to switch automatically between the FX and DX formats when one of the smaller format Nikkor lenses is fitted.