It seems like lately I’ve been in a lens frenzy. In the past, I’ve normally bought (changed) one lens per year on average. Last year I got two and now I have yet another new lens.

The thing is, since I got into wideangle photography, the Canon 24-105mm lens that’s been my normal walkaround lens is suddenly not very wide. 24mm is 38mm on an APS-C sensor, it was fine as long as I couldn’t make any sense of wideangles anyway. At the same time, a true walkaround lens needs some proper extension in the long end, so I couldn’t consider anything shorter than 100mm (in the far past, I had the Canon 17-85mm which I traded for the 24-105, because I couldn’t use the wide end and the long end was too short!). In addition, I have now decided that I will continue with the APS-C size sensor cameras (waiting for the follow-up to 7D).

Enter the Sigma 18-125mm f3.8-5.6 DC OS HSM. The Tamron 18-270mm superzoom was also an option and even though all the reviews pegged it about equal with the shorter Sigma, somehow I felt it was a safer bet to go for the shorter lens.

I can imagine you’re asking why I would trade a sharp Canon L lens for a cheap Sigma. Believe it or not, but I don’t think I’m losing so much here. Since I got the Tokina wideangle zoom(s), I noticed that my Canon zoom isn’t actually so super-sharp anyway, the Tokina(s) beat it. So I figured, the lens profile tools in Lightroom are really good and they can fix many of the shortcomings in the lenses. I’ve never even used the sharpening tools but I could start using them now if needed, unless my Sigma was a total lemon.

I got the lens on Friday, perfect timing. I’ve never been good at lens testing so I just took the pictures I would take anyway, plus just a few extra frames at fully open to see how it copes. And this is what I found:

• f8 and you’re there
• Fully open it’s soft as a baby’s butt. Horrible. But when did I ever use the Canon 24-105 fully open? Almost never.
• CA is epic. The wideangle Tokina lenses have a reputation for CA, but they’re just amateurs in comparison with the Sigma. A little bit of Lightroom magic though and the CA is gone, except in the most extreme cases (like tree branches against an overexposed sky). The Sigma is in good company in those situations though.
• The optical stabilisation is quiet and almost unnoticeable in the viewfinder. I’m used to the purring of the IS and the hopping in the viewfinder when using the Canon zoom but the Sigma is so quiet and solid in the viewfinder that at first I thought the OS was broken. It’s not.

In conclusion, I got exactly what I paid for and I got exactly what I expected. Obviously, one day and just a handful of pictures is not enough to be absolutely certain but my gut feeling is that the Sigma is good enough for my uses and the only thing where I have any significant loss of image quality is when shooting wide open. A quick look in LR tells me that I have 38 pictures shot at wide open with the Canon zoom in the 6 years I’ve had it. That’s 1 picture every other month on average, I can live with those odds!

I am happy with my decision to go with the Sigma and it will be my new walkaround lens. For the really ”serious” pictures, I have the specialist lenses – Tokina 11-16mm for landscapes, Sigma 150mm for macro and Canon 300mm for animals. I hope that this kit will serve me for many years to come, because I can’t afford to keep buying lenses at the rate I’ve been doing in the past year!