Compared to...

Studio scene comparison (JPEG) - 6 & 8 megapixel cameras

This is our standard studio scene comparison shot taken from exactly the same tripod position. Lighting: daylight simulation, >98% CRI. Crops are 100%. Ambient temperature was approximately 22°C (~72°F).

Nikon D80 vs. Nikon D70s
10 MP vs. 6 MP

Camera settings:

• Nikon D80: Nikkor 50 mm F1.8 lens, Aperture Priority, ISO 100
  JPEG Large/Fine, Manual WB, Default Parameters (Normal), Self-Timer (+exp delay)
   
• Nikon D70s: Nikkor 50 mm F1.8 lens, Aperture Priority, ISO 200
  JPEG Large/Fine, Manual WB, Default Parameters (Normal), Self-Timer

Nikon D80 (10 MP)	Nikon D70s (6 MP)
3,728 KB JPEG (3872 x 2592)	2,772 KB JPEG (3008 x 2000)

A sixty-six percent increase in pixel count, we would expect to see a significant difference, and it's clearly visible. The D80 delivering quite a bit more detail than the six megapixel D70s. That said you would only see a difference between them in 8x11 prints or larger.

Nikon D80 vs. Canon EOS 350D (Digital Rebel XT)
10 MP vs. 8 MP

Camera settings:

• Nikon D80: Nikkor 50 mm F1.8 lens, Aperture Priority, ISO 100
  JPEG Large/Fine, Manual WB, Default Parameters (Normal), Self-Timer (+exp delay)
   
• Canon EOS 350D: Canon EF 50 mm F1.4 lens, Aperture Priority, ISO 100
  JPEG Large/Fine, Manual WB, Default Parameters (Standard PS), Self-Timer (+MLU)

Nikon D80 (10 MP)	Canon EOS 350D (8 MP)
3,728 KB JPEG (3872 x 2592)	2,882 KB JPEG (3456 x 2304)

Compared to a sharp eight megapixel such as the Canon EOS 350D / Digital Rebel XT the differences are more difficult to identify with only a 25% advantage to the D80. Indeed despite several passes up and down the crops (and examining the rest of the image) I was unable to identify anything in the D80 image which wasn't resolved just as well as the eight megapixel 350D (there really is no useful difference between 8 and 10 megapixels).