Lens resolution

Canon were good enough to loan a few lenses with the D30 (as summarised in the introduction to this review). When shooting the resolution chart for the image quality tests I thought it would be important to compare the performance of some of the lenses, especially the expensive "L" lenses against the cheaper "normal range". We only test three lenses which each covered the same 70 mm focal length (chosen as the common focal length for the resolution chart tests).

Colour accuracy

	Measured colour:   Red Green Blue Blue patch 15% 14% 40% Cyan patch 10% 59% 87% Green patch 11% 53% 26% Yellow patch 82% 75% 13% Red patch 79% 20% 23%
Canon EF 24 - 85mm F3.5 - F4.5 USM, 1/3s, F6.3
	Measured colour:   Red Green Blue Blue patch 14% 12% 35% Cyan patch 9% 53% 78% Green patch 10% 45% 21% Yellow patch 76% 67% 9% Red patch 73% 16% 18%
Canon EF 28 - 135mm F3.5 - F5.6 IS USM, 1/3s, F6.3
	Measured colour:   Red Green Blue Blue patch 18% 16% 42% Cyan patch 12% 58% 86% Green patch 13% 52% 25% Yellow patch 82% 74% 14% Red patch 79% 21% 23%
Canon EF 28 - 70mm F2.8 L USM, 1/3s, F6.3

Resolution

Canon EF 24 - 85mm F3.5 - F4.5 USM, 1/3s, F6.3
Canon EF 28 - 135mm F3.5 - F5.6 IS USM, 1/3s, F6.3
Canon EF 28 - 70mm F2.8 L USM, 1/3s, F6.3

Overall conclusion? Well the 24-85mm does seem to be a very good match for the D30, and it offers the same resolution as even more expensive lenses, the 28-135mm IS was also very good offering equal resolution.

So why would you want to buy an "L" lens? I can't see any major colour or resolution advantage (at least with the 3 megapixel D30), you do of course get a faster, higher build quality lens with (probably) faster auto focus perfectly suited to pretty much any situation. That said a good "L" lens will make the whole package quite a bit heavier.

For more info on Canon lenses check photo.net