Following on from my last post, Canon has been slowly upgrading its lens line-up, announcing Mark II versions of popular lenses from time to time. Let’s look at some of these efforts based on the controversial perceptual megapixel measurement used by DxOmark.com.
First up to bat is the popular 70-200 F2.8 L lens introduced in 2001.
This lens was always considered a pretty sharp part of the arsenal. Yet, Canon introduced a mark II version of the lens in 2010. Has the new lens improved on the old? You bet. The old lens pulled down a mediocre P-Mpix score of 13 on a Canon 5d MKII, while the new lens offers a flashy 18 P-Mpix score, a perceived resolution increase of nearly 40%.
Another lens upgrade was the 16-35 F2.8 L.
The original lens was announced in 2001. The mark II lens was announced in 2007. Both lenses scored a middling 12 P-Mpix, so it looks like older upgrades were aimed at the resolution of the cameras of the day.
A more recent upgrade was to the EF 300 mm F2.8 lens, a lens that sells for over $6,000.
The original model was announced in 1999. The new model was announced in 2010. The original model was pretty sharp at 17 P-Mpix. The new model delivers 21 P-Mpix, the highest score you can get on a 21 megapixel sensor camera. This lens is obviously being positioned to delivery results in Canon’s next range of 40 megapixel bodies.
Of course, the main tool of many pro shooters is the EF 24-70 F2.8 L. Canon issued a mark II model of this lens in February 2012, but DxOmark has not tested the lens yet, so we don’t have the P-Mpix measurement for the newer lens. We do know, however, that the new lens costs a lot more than the old one, so expectations are high. The folks over at Photozone have reviewed both versions of this lens and the MTF resolution numbers at 40mm are as follows:
As you can see, centre resolution on the older lens is certainly no slouch at over 3500 line pairs per sensor height, but the new lens is definitely sharper in the centre and on the borders. Strangely, the extreme corner readings of the old lens are sharper than those of the new lens.
It will be interesting to see how these MTF numbers translate into a P-Mpix number. The old lens is rated at a P-Mpix of 12, quite a middling reading for a lens of this importance.
The DxOmark P-Mpix statistic indicates that lenses are now the main bottleneck in getting resolution from the sensor to the image file. Manufacturers like Nikon, Sony and Canon need to go back to the drawing board and start releasing lenses that match the resolving power of their sensors. This is tricky because lenses are not subject to Moore’s law and don’t automatically get better every few years as silicon wafer technology improves. It takes hard work and investment to build sharper lenses.
It is apparent that Canon is taking this challenge seriously. New lenses like the EF 70-200 F2.8 IS L II lens clearly out-resolve the lenses they replace in the line-up. Brand new lenses like the EF 40 STM pancake show that they are ready for large sensor cameras. However, some staples like the EF 24-105 F4 are lagging sensor resolution and need upgrading before Canon unleashes its next round of large sensor cameras, rumoured to be coming down the road in 2013.