RAW image format

RAW is simply pixel data as it comes directly off the CCD, no in-camera processing is performed. Typically this data is 8, 10 or 12 bits per pixel. The advantage being that file sizes are considerably smaller than an equivalent TIFF file. The image has not been processed or white balanced which means you can correct the image, and it's a better representation of the "digital negative" captured. The disadvantage is you can't open these image files with a normal photo package, in the case of Nikon RAW files (.NEF) you must use Nikon View or Nikon Capture.

A little background: each pixel of a CCD can only see one colour, depending on the CFA (colour filter array) placed over the CCD this is either Red/Green/Blue or Cyan/Magenta/Green/Yellow. The cameras internal image processing engine then interpolates colours from the value of neighbouring pixels to calculate a full 24-bit colour for each pixel.

As we would expect the Coolpix 5700 generates 7.7 MB .NEF RAW files, this works out correctly when you take into account the file header and calculating that each pixel is recorded as a 12-bit value (2560 x 1920 x 12 / 8 = 7,430 KB).

The Coolpix 5700 is supplied with Nikon View 5.1 which includes Nikon View Editor, a rudimentary RAW conversion application. For more sophisticated manipulation of RAW files you can also purchase the optional Nikon Capture 3.0. I covered both of these applications in some detail in my Nikon D100 review, click here to read about Nikon View 5.1 and Capture 3.0.

Nikon View 5.1 Editor vs. Nikon Capture 3.0

The Coolpix 5700's NEF files appear to take considerably longer to process than NEF files from Nikon D-SLR's (D100, D1x, D1H etc.), I'm not quite sure why this would be. In any case here's a feature and performance comparison between the two applications. The test machine used was a desktop PC with dual Athlon 1592 Mhz (1900+) CPU's 1 GB of RAM.

Detail Nikon View 5.1 Editor Nikon Capture 3.0
Save as • TIFF RGB (8 / 16 bit)
• JPEG (5 levels)
• TIFF RGB (8 / 16 bit)
• JPEG (5 levels)
• Nikon RAW NEF
Save image portion Yes, bounding box Yes, bounding box
Output color space Always Nikon sRGB Always Nikon sRGB
Re-save NEF Yes Yes
Edit IPTC information No Yes
Batch NEF processing No Yes
View exposure data Yes Yes
Rotate & Flip Yes Yes
Digital exposure compensation Yes, +/-2 EV, 0.3 EV steps Yes, +/-2 EV, 0.01 EV steps
White balance adjust Yes, no gray point picker Yes, including gray point
Sharpening adjust No Yes
Tone adjust No Yes
Hue adjust No Yes
Saturation compensation No Yes, 9 levels of less saturation
Noise reduction No • Color Noise Reduction
• Edge Noise Reduction
General adjustments • Auto contrast & color
• Auto contrast
• Image size
• Image size
Unsharp mask No Yes
Curves / Levels No Yes
Color balance • Brightness +/- 50 steps
• Contrast +/- 50 steps
• R, G or B +/- 50 steps
• Brightness +/- 50 steps
• Contrast +/- 50 steps
• R, G or B +/- 50 steps
Misc.   • Bird's Eye View
• Information
Load / Save / Copy settings Yes Yes
Open image 15.8 sec 17.5 sec
Time to adjust (normal) * 15.8 sec 15.8 sec
Time to adjust (zoomed out) * 2.4 sec 2.4 sec
Save as JPEG (Good quality) 2.8 sec 3.1 sec

* Exposure compensation -2 EV

RAW vs. JPEG (the watch)

This is our standard watch scene shot as both FINE JPEG and RAW NEF, the crops shown are taken from an 8-bit TIFF created by Nikon View 5.1 Editor from the NEF file. As you can see there is very little difference between the JPEG FINE and RAW images, sharpness, balance and dynamic range are all identical. Perhaps the only slight difference is a little less visible noise in shadow areas (but it's slight).



The crops below are from shots taken of a standard PIMA/ISO 12233 resolution test chart, as you can see shooting RAW on the 5700 doesn't deliver any discernible resolution advantage.


RAW dynamic range

Both Nikon View Editor and Nikon Capture allow you to digitally 'exposure compensate' the image, this can be used to pull detail out of highlights or shadows. By adding digital exposure compensation of -1.0 EV to our standard shot we can see that the 5700 RAW image does indeed contain information we couldn't see in the original +0 EV shot.

RAW +0 EV RAW -1.0 EV