The Canon 135mm f/2L has a reputation for being one of Canon's sharpest lenses. I spent a weekend doing model portfolios with a 135mm and decided to write a review based on actual experience when photographing people rather than writing about technical data.

I have worked extensively with the 70-200mm f/2.8L and my normal portrait lenses are the 50mm f/1.4 and 85mm f/1.8

Results are perfectly usable at f/2 at closer distances - one of the benefits of buying a L series lens is that photographs are usually sharp when shooting at the widest aperture. I found that when shooting from a distance at a wide aperture you do need to stop down a bit, but working at closer distances the pictures from this lens are very sharp.

I compared pictures taken with the 135mm f/2.0 and that taken with the 85mm f/1.8 and results are very similar. Bokeh on both are very pleasable and I couldn't see any obvious real-life differences between the two lenses, despite the L badge and the significant price difference between the two.

The biggest advantage of the 135mm f/2L lens over the 70-200mm f/2.8L IS lens is the close focusing distance of only 0.9m compared to 1.5m on the 70-200mm f/2.8L IS lens. This means you can get in really close to your subject to throw the background out of focus.

Based on my experience of working with the 70-200mm f/2.8L, image sharpness is marginally better on the 135mm f/2L, but not significantly. (When working at wider apertures and closer focusing distances you have to make sure that your focusing is spot on - when working with people you have to make sure that you focus on the eyes else your subject will appear out of focus.)

Although the 135mm f/2L lens is a faster lens by 1 stop, IS on the 70-200mm lens will make the 70-200mm lens the obvious choice for low light shooting. The main advantage of the faster stop is more pleasing bokeh when shooting wide open. Auto focus on the 135mm f/2L lens is noticeable faster than that of the 70-200 f/2.8L IS lens. Other advantages over the 70-200mm are it's smaller less intimidating size, lighter weight and it's black color (less obvious when shooting candid's and portraits) when compared to the 70-200.

Conclusion

If you are looking for a sharp lens with great bokeh and a fast aperture in the 135mm range, you can't go wrong with the 135mm f/2L. Pictures are sharp but not noticeable better than pictures from the 70-200mm f/2.8L IS at 135mm. The lens really shines as a headshot lens and pictures taken at close range and wide apertures are what give this lens an advantage over other portrait lenses. However, the 135mm is a bit limiting when it comes to portraits as it requires you to distance yourself quite a bit more from your subject than the 85mm or 50mm lenses do.

If you are after a portrait lens that produces sharp pictures with pleasing bokeh and a fast aperture, the 85mm f/1.8 and 50mm f/1.4 are excellent choices that provide results just as good as those from this lens, but at a much better price.

Whichever way you look at it, the 135mm is a very specialised lens. The focal lenghts' of the 50mm, 85mm and 70-200mm lenses are so much more versatile. However, those wanting the best 135mm money can buy won't be disappointed by the quality that this lens produces.

Pros
0.9m closest focus distance
Very sharp lens
Great bokeh
Fast, silent Autofocus
Light weight and small size compared to 70-200
Black color makes for discreet telephoto lens
One of the cheaper L lenses money can buy

Cons
135mm will be too long as a portrait lens on 1.6 crop sensors (EOS 40D, EOS 400D)
Sharp lens, but results aren't that much better than the 85mm f/1.8 or the 70-200mm f/2.8L
Limited range when compared to 70-200
Lack of IS will handicap lens in low light situations
Cheaper options with similar results available in Canon lens lineup if you are looking for a portrait lens
135mm is a bit limiting when it comes to portraits