Image Size / File Quality Options

The D70 provides for selection of output image size and quality separately, it provides three different image size options of 3008 x 2000 (6.0 million pixels), 2240 x 1488 (3.3 million pixels) and 1504 x 1000 (1.5 million pixels). These can be selected in combination with three JPEG quality levels of Fine, Normal or Basic. Additionally of course there is RAW mode (Nikon NEF format), which is losslessly compressed (a bit like zip compression). Lastly there is also a RAW+JPEG mode which outputs a separate RAW file and Large JPEG, the disappointment with this feature however is that the JPEG is output at Basic quality and there is no option to change it.

Standard Test Scene

To give an impression of what some of the combinations of image size and quality produce the table below is a cross reference of some of them:

• 3008 x 2000 RAW (to TIFF using Nikon Capture 4.1)
• 3008 x 2000 JPEG Large / Fine
• 3008 x 2000 JPEG Large / Normal
• 3008 x 2000 JPEG Large / Basic
• 2240 x 1488 JPEG Medium / Fine
• 1504 x 1000 JPEG Small / Fine

Crops below are of the same 240 x 100 area of each image nearest neighbour magnified 200%.

Settings: Parameters: Normal, ISO 200, Nikkor DX 18-70 mm

	3008 x 2000
RAW	5,515 KB .NEF (Nikon RAW), VGA crop - 661 KB .TIF
JPEG Fine	2,612 KB
JPEG Norm	1,349 KB
JPEG Basic	703 KB
	2240 x 1488
JPEG Fine	1,542 KB
	1504 x 1000
JPEG Fine	845 KB

As you can see Nikon Capture renders the RAW image with more contrast (and also more color saturation) than the in-camera processing algorithm. It is quite difficult to see any JPEG artifacts at the Fine or Normal compression settings, dropping down to Basic does introduce 'mosquito' type artifacts around detail as well as the smoothing of large areas of similar color.

Color modes

Just like other Nikon digital SLR's the D70 provides three color modes, Mode Ia and IIIa are both mapped to the sRGB color space and so images shot in these modes will look correct immediately and can be used as is. Color mode IIIa has been designed for use for nature and landscape shots, it provides richer greens and a more natural balance of other colors.

Mode II is mapped to the Adobe RGB color space, this provides for a wider color gamut but will require conversion to sRGB for computer monitor output. Many professional photographers and publications have standardized on Adobe RGB, this ability is now expected of almost all digital SLR's. The D70 uses a different filename mask for Adobe RGB images, they begin with "_DSC" instead of the normal "DSC_". They are also now embedded with the Adobe RGB color profile, this means that color space aware applications such as Adobe Photoshop immediately recognize and apply the correct color profile.

GretagMacBeth ColorChecker samples

Place your mouse over the labels below the image to see the GretagMacbeth ColorChecker chart taken in each color mode.

Settings: Parameters: Normal, ISO 200, Nikkor DX 18-70 mm

Ia (sRGB)	II (Adobe RGB)*	IIIa (sRGB)

* Note that the Adobe RGB image has been converted to the sRGB color space for correct display in your web browser.

Studio scene samples

Note that in these samples the Adobe RGB image has NOT been converted to sRGB and so to view it correctly you will have to load it into a color space aware photo application and assign the Adobe RGB color space. Below each sample is that image's CIE u'v' Color Distribution chart; larger gray triangle approximately represents the range of color which the human eye can resolve, the inner triangle the available gamut in each color space (sRGB or Adobe RGB).

Settings: Parameters: Normal, ISO 200, Nikkor DX 18-70 mm, F14 (Studio strobe)

Ia (sRGB)	II (Adobe RGB)	IIIa (sRGB)