Sorry if my question seems a bit naive. I was wondering what is the main difference between the Canon EF 14mm f/2,8 L USM and the Canon EF 14mm f/2,8 L II USM ? And correct me if I'm wrong, but because these two lenses are from the L series, these two can be mounted on a Canon 5D Mark III, right ?
Any EF lens can be used on one of Canon's full-frame cameras.
Generally, when Canon makes a newer version of a lens, it's because there can either be improvements to the optical design, or they can make a cheaper version of the lens. With Ls, it's usually the former. The Mk I version of the 14L came out in 1991. The Mk II version in 2007, so you are talking 16 years' worth of optical design advances between the two. Essentially, the main optical designs remain similar, but the MkII has been tweaked with a few more exotic elements added.
From Canon USA's Camera Museum website, the block diagrams of the two designs are:
EF 14mm f/2.8L USM
The green element is aspherical.
EF 14mm f/2.8L USM II
The dark green elements are UD (ultra-low dispersion glass) elements, and the two light green elements are aspherical.
Aspherical elements can add sharpness and reduce aberrations. UD and flourite elements can help with chromatic aberration correction.
First off, all EF lenses (L or otherwise) can be mounted on a Canon 5D. Nothing about the L precludes it from being mounted on other bodies, nor only the higher end bodies being restricted to only L lenses.
The difference between the two (and I'm working from Ken Rockwell's review at Canon 14mm f/2.8 L II)
- Heavier (4oz heavier than the original)
- Built in shade is different
- Sharper at edge (fixes color fringing)
- Rear gasket for sealing against the elements
- Cosmetic differences in styling.
The improved sharpness can be seen in the MTF charts provided by Canon for the two lenses:
Original 14mm f/2.8 L via wayback:
New 14mm f/2.8 L II from Canon:
You can certainly see better and more consistent performance across the board with the 14mm f/2.8 L II.
I have recently used this lens and having a copy of the old lens, I could instantly see the difference in quality. The images are sharper towards the edges (way Sharper). I tested in backlit situations, and the purple fringing is way way reduced compare to the older model.
The copy of the lens that I have, produced a slightly colder tint compared to the older version. I prefer warm tints, but easily corrected in LR.
There is not enough difference in the weight, not that it mattered as I used it for landscape on a tripod with the mirror locked. I must mention the sharpness again, it is immense.
I also found that after Lens correcting in LR, more of the picture remained when compared to the older lens. I took a few cityscapes that needed adjusting and it was nice to see that I was able to retain so much as the buildings were not leaning as much as the older model.
I haven't read any of the tech specs, but I guess it just boils down to newer lenses!