The EF 50mm lenses from Canon are probably the most talked about lenses I’ve come across (in the world of Canon). Their popularity is no doubt partly due to the great value of the f/1.8 flavour, which costs less than £70, in light of the sharpness a fixed focal length lens brings.

As well as the f/1.8, there are f/1.4 (2/3-stop faster than f/1.8) and f/1.2L (1/3-stop faster than f/1.4) versions each with their own strengths and weaknesses.

• 50mm f/1.8 (aka nifty fifty) offers sharpness, shallow depth of field and low-light capability in a very light and inexpensive lens.
• 50mm f/1.4 improves on the build quality, image quality, autofocus performance and bokeh of the f/1.8.
• 50mm f/1.2L delivers the best sharpness, image quality and build of the range, but at a cost of money and weight.

On a full-frame camera these lenses offer a versatile focal length suitable for a wide variety of different subjects.  On a cropped sensor body, the 50mm focal length moonlights well as a short portrait lens, highly usable for full-body through to head and shoulder portraits.  The maximum f/1.4 aperture is very effective at blurring backgrounds helping subjects to really pop out of a photo.

I used to own a 50mm lens on my old Canon 1000FN, but must admit that it didn’t get to see much action.

Now, with my 1.6x cropped sensor 40D, my 70-200mm f/4L is just too long to get the kind of bokeh I really want for portraits and as good as my EF-S 17-55mm f/2.8 is sometimes its depth of field just isn’t shallow enough.

After seeing its almost cult-like following and a number of wonderful shots (including this one), I decided to take the plunge again with a 50mm lens after deciding the EF 85mm f/1.8 would just be too long for portraits on my 40D.

Interesting to note that Canon’s 50mm f/1.4 seems to fall behind in the sharpness and contrast stakes when compared against Sigma’s own 50mm f/1.4.  Here’s a link to a 100% crop comparison of Canon EF 50mm f/1.4 USM and Sigma 50mm f/1.4 EX DG HSM and I’m afraid to say that the difference is very apparent.

Given that the Sigma costs about £100 more than the Canon it ought to perform better, but of course they’re just photos of charts.  What’s more important is their performance in the field and I’m glad to report the Canon’s no slouch in any department.  What’s more, the shallow depth of field and bokeh - albeit octagonal - make for very pleasing results.