Friday, January 22nd 2010

Sharpness test: Sigma 17-70mm vs Canon 17-55mm

After having bought my second hand EF-S 17-55mm f/2.8 I sold my Sigma 17-70mm f/2.8-4.5. But before I sent it off to the buyer, I took some test shots for a little comparison of the two lenses.

I set my camera up on my tripod and took shots of our bookcases from roughly 2.5 meters away, at a right angle. I took photos at 17mm, 35mm and 55mm with both lenses, and at each focal length I took photos at f/2.8, f/4.0, f/5.6 and f/8.0. (Obviously, the Sigma doesn’t do f/2.8 at 35mm and 55mm.)

One thing I did notice fairly soon was that the Sigma’s autofocus was much less reliable than the Canon’s. For some of the shots I ended up having to manually hunt for the optimum focus distance. The Canon got it right every time.

From each test shot I have cropped out sections from the centre, mid and edge areas. All in all, 66 squares of 300×300 pixels, which I have ordered in (hopefully) pretty tables below.

As you can see in the overview photos, the sections are taken from different places for the different focal lenghts. (To use the areas of the bookcases with most detail in them.)

I’ve put my own conclusion in words at the end, after all the tables.

Overview of sharpness test of Sigma 17-70mm f/2.8-4.5 and Canon EF-S 17-55mm f/2.8 IS

17mm – Centre
Aperture Sigma 17-70mm f/2.8-4.5 Canon EF-S 17-55mm f/2.8 IS
f/2.8 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/4.0 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/5.6 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/8.0 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
17mm – Mid
Aperture Sigma 17-70mm f/2.8-4.5 Canon EF-S 17-55mm f/2.8 IS
f/2.8 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/4.0 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/5.6 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/8.0 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
17mm – Edge
Aperture Sigma 17-70mm f/2.8-4.5 Canon EF-S 17-55mm f/2.8 IS
f/2.8 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/4.0 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/5.6 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/8.0 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS

Overview of sharpness test of Sigma 17-70mm f/2.8-4.5 and Canon EF-S 17-55mm f/2.8 IS

35mm – Centre
Aperture Sigma 17-70mm f/2.8-4.5 Canon EF-S 17-55mm f/2.8 IS
f/2.8 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/4.0 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/5.6 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/8.0 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
35mm – Mid
Aperture Sigma 17-70mm f/2.8-4.5 Canon EF-S 17-55mm f/2.8 IS
f/2.8 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/4.0 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/5.6 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/8.0 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
35mm – Edge
Aperture Sigma 17-70mm f/2.8-4.5 Canon EF-S 17-55mm f/2.8 IS
f/2.8 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/4.0 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/5.6 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/8.0 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS

Overview of sharpness test of Sigma 17-70mm f/2.8-4.5 and Canon EF-S 17-55mm f/2.8 IS

55mm – Centre
Aperture Sigma 17-70mm f/2.8-4.5 Canon EF-S 17-55mm f/2.8 IS
f/2.8 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/4.0 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/5.6 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/8.0 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
55mm – Mid
Aperture Sigma 17-70mm f/2.8-4.5 Canon EF-S 17-55mm f/2.8 IS
f/2.8 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/4.0 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/5.6 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/8.0 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
55mm – Edge
Aperture Sigma 17-70mm f/2.8-4.5 Canon EF-S 17-55mm f/2.8 IS
f/2.8 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/4.0 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/5.6 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS
f/8.0 Sharpness test of Sigma 17-70mm f/2.8-4.5 Sharpness test of Canon EF-S 17-55mm f/2.8 IS

Conclusions

On the whole, in almost all of the little squares, the Canon is running circles round the Sigma. No pun intended actually.

Surprisingly though, the Sigma looks sharper than the Canon in the centre and mid areas of the frame when using f/2.8 at 17mm. The Canon seems to suffer from some kind of fringing here. (At the edges though, the Canon is better.)

To summarize, it was much as I had hoped and expected. But I would be lying if I said I wasn’t a little disappointed with the Canon’s performance at 17mm. At the same time I don’t think that fringing will be very visible with most subjects. It would take a lot of fringing to out-weigh the benefits of having image stabilization.

3 Responses to this post:

  1. Andrew says:

    Im so glad i found your comparison! I was curious towards sigmas auto focus. i previously had the 18-200 and i also had a hard time with the AF, eventually finding the range myself. I was looking into the sigma for a cheap alternative to a wide zoom. I am most likley purchasing the 7d, but may hold off as your 60D prediction has stumbled me on my choice! SO many decisions! If you have any good lens recommendations with 2.8/f, or personal experiences and feed back would be much appreciated! Lens review was simple and awesome!

  2. Jian says:

    Your review was awesome.
    That what i looking for the Canon 17-55mm lens compare with Sigma 17-70mm

  3. David Naylor says:

    Great, glad you found it useful!