A surprisingly good lens for its money

I bought the Sigma 18-50mm as a wide-angle and general purpose lens for my Canon 10D and I have to say I was very pleasantly surprised. Despite being a relatively cheap lens, it gave me some very good shots indeed.

Now, let's not get carried away and make sure we see this for what it is, or even for what it isn't. It is not a Canon L series nor is it a Sigma EX series so let's not be silly and start making false comparisons. This is a great starting lens when you are spending most of your money on a body only camera and need your first lens to start taking pictures. That is precisely where I was at when I first got my 10D.

So, ok it isn't a razor sharp dream machine but would you really expect that at this price? Some might even think this lens belittles a camera of the quality of the 10D. Well let me assure you.... it doesn't! it is a very decent lens throughout its range. The widest aperture reduces as you go towards 50mm and frankly f5.6 for 50mm is really not great. However, most people buying this lens will be using it on one of the Canon DSLRs and therefore the 1.6 multiplication factor should be taken into account. This then is really a 27mm-80mm lens which is is a decent range as a 'standard zoom' for general purpose use.

It doesn't have the curved aperture diaphragm of an L series lens and therefore the bokeh is not the softest but it is decent enough for very acceptable portraits. Bokeh, by the way, is the quality of the blurring of backgrounds when using reduced depth of field. I would use this lens at the 50mm end (80mm equiv) and enjoy taking very pleasing portraits. I recently did a photo shoot for a local university who required publishable portraits of over 150 graduates. I used this lens and they were delighted with the results.

The Autofocus works very well, it isn't as quiet as a USM lens (HSM in the Sigma range) but then it is not going to wake a sleeping grandad either! It doesn't hunt very much but for this range I wouldn't really expect it to.

It comes with a petal-shaped lens hood which usefully reverses to fit over the lens body for storage. It is certainly something you need when using this range of focal lengths though this lens does not suffer any more than I would expect from lens flare. If the main light source is within 45 degrees, I would certainly use the hood. The one slight drawback is if you choose to use a polarising filter. Given that you would almost certainly have a UV filter on as a matter of course (you do, don't you?!) when you add the polariser as well, the hood becomes virtually redundant as it is mounted so far back that there is little left of it ahead of the front element.

Some people considering this lens will be using the 300 or 350D and will be considering this against the EF-S lens in the Canon range. I would say you will notice very little difference in quality between the two. The Sigma lens is optimised for digital use despite not having the extended rear element that puts it closer to the sensor. If you tried using this lens with a film SLR you would notice some vignetting around the corners. However, it CAN be used for that and for certain portraits, that vignetting can be perfectly acceptable or even desirable.

The EF-S lens would not be usable on a film SLR camera at all as it would clash with the mirror. If you, like me, use both a digital and a film body (I just can't give up my slides!) the option to use it with the latter may be something to consider.

This lens is now available at prices that are frankly giving it away and taking that into account, if this is what you need and budget is limited, I would definitely recommend it.