When buying a lens, you have two options: brand (Canon lenses for a Canon camera, and so on) or third party (“Sigma made for Canon”, and so on).
Third-party lenses are often half the price of brand name lenses. Brands say “that is because ours are better”. Third parties, like Sigma, maker of the 24-70 f/2.8 Nikon-mount lens below, would probably say “this is because you pay for the name with those guys”. Which is it?
A bit of both, I think.
I would certainly consider a third-party lens. If:
- aperture is large,
- build quality is good,
- focus is silent, fast and accurate,
- the lens is sharp, even at the corners,
- colour is good,
- and importantly, the lens feels good to me..
…then I will most certainly consider it. And third-party lenses often have better warranty than Canon and Nikon offer.
But that also brings me to why – perhaps because these warranties are needed. The lens above is the third one that its owner tried in about two weeks: lens number one did not always focus consistently, so it was exchanged in its first week, and lens two suddenly stopped focusing after just a few days – the focus motor stopped working entirely in mid-shoot. Lens three, we hope, will work well.
Now that is from a sample of one (well, three). So you cannot draw any conclusions from it. But still… in the past, reliability and quality control used to the the third-party lens makers’ Achilles’ Heel. There is either a certain irony, or a wise lesson, in the fact that two samples of this lens failed in two weeks.
But the lower price – significantly lower – is hard to pass by. I think whatever you choose, you will be fine, as long as you go through the check list above abnd make sure the warranty is OK.
And remember: lenses make your photos, much more than your camera does. So whatever lenses you invest in – investing in lenses is never bad.