Canon 24-105mm f/4L IS USM EF Lens

I bought this lens after using a Canon EF 28-135mm F/3.5-5.6 IS USM for a couple of years. My photographic style had centred around a type of image that the 28-135mm didn't have the resolving power to cope with, although it had been a very good lens to me. I suspect that someone somewhere will also be wondering whether to make the same upgrade, so I'll try to help as much as I can.

The first, and most obvious difference between the two lenses is build quality. The 28-135mm isn't bad, but there is (what I would call) considerable play in the lens' extending barrel even when it's not extended, although it is worse when stretched to its full 135mm reach. The 24-105mm is very solid, and even when the lens is extended to 105mm there is not a single millimeter of play - just what I like. Also, as it is part of the L series family, the materials used to build the 24-105mm are fantastic quality and feel lovely in the hand, making the 28-135mm seem plasticky in comparison.

In use the lenses handle relatively similarly, apart from a tiny bit of play in the 28-135mm's zoom ring that is absent from the 24-105mm. As a result the 24-105mm has a more positive zoom action that is hard not to get spolit by - going back to the 28-135mm feels like being demoted, even though it's not a bad lens!

Image stabilisation (it has a 'z' but I refuse to spell like an American!) features on both these lenses, but the 24-105mm sports a newer, better model. It's silent and so smooth you have to make sure occasionally that it is turned on. In contrast the 28-135mm makes a constant whirring humming noise, with an even louder motor noise that lasts for a split second when the stabiliser starts up and shuts off.

Both lenses are lightweight enough to balance well on my 35mm EOS 30 which is about 500g or so. The slightly weightier 24-105mm would still match well on one of Canon's 'mid range' DSLRs like a 30D or 5D.

Image quality is something of a minefield in a review. Most people have different opinions of what is good image quality, but in my opinion the 28-135mm loses too much sharpness towards the edge of the frame when wide open, although in general use it performs very well.

It's in high contrast photography that I noticed the biggest difference in peformance between these two models. The humble 28-135mm can't hide the chromatic abberation (CA) around subject edges, e.g. leaves against a bright sky. The 24-105mm performs much better, and I haven't noticed any CA yet. Very impressive. Neither seems to render colours any better than the other, indicating that the 28-135mm punches above its weight.

Centre sharpness of the two isn't as different as you might think. Both are pin sharp in the middle, but the 24-105mm holds onto this sharpness across most of the 35mm frame, when the 28-135mm falls behind.

Focusing is quick and quiet with both units. In normal conditions the more expensive L lens has the edge, but I would have expected it to do better in certain (admittedly rare) situations, where it can sometimes fail to find a focus point.

To sum up, as I am running out of characters, the EF 24-105mm F/4 L IS USM is a convincingly better lens than the EF 28-135mm F/3.5-5.6 IS USM. However, I have perhaps been spoiled by it, and must admit that for about 24 months I thought the cheaper lens was more than good enough. It comes down to what you can afford. Got the money? Go for the L! On a budget? The 28-135mm will serve you well.

Pros:
Excellent build quality, fast and reliable AF, good 3 stop stabilization.
Excellent resolution for the wider focal distances. Good resolution for the longer focals. Nice portrait capabilities.

Cons:
The zoom ring on my sample is quite stiff.

How can you rate an L lens as anything less than excellent? Well, call me picky but I'm disappointed that this lens isn't a huge improvement on the optical performance of the Canon EF 28-135mm IS, but more than this, I'm amazed at the barrel distortion at 24mm. It is correctable using PSPro or (with a little more effort) Photoshop, and perhaps I'm expecting too much, even of an L lens! That said, the build quality and "Rolls-Royce" feel is what you're paying for, and in this respect it doesn't disappoint at all. The zoom ring is silky smooth, and AF is as silent and fast as you could want. It just feels like quality, and is - in this area - a quantum leap from the 28-135 IS.

Optically it is noticeably more contrasty than the 28-135, so that's a good thing, and as you'd expect having spent out around double the money. It is, actually, sharper than the 28-135 particularly at the extremes of the zoom range, and at full aperture. At around f8 I think you'd be hard-pressed to see any difference at all. So don't expect a huge difference in the sharpness of your shots if you trade up from the 28-135 IS.

What you get for your money is pleasure! This is just a nice lens to hold and use, and one which will continue to please for a long long time. It does have its shortcomings, unlike for example the 100-400 L which, used carefully, produces absolutely stunningly sharp images that just glow, somehow. Despite the shortcomings though, it's still a lens I would recommend over the 28-135 IS. The difference between 24mm and 28mm is a very useful one, and well worth the trade-off at the other end of the zoom range.

If you are struggling with the dilemma of swapping your 28-135 IS for the 24-105 L (as I did), I'd say that if you can afford to make the swap, then do it - you may not see a vast improvement in IQ, but you will thoroughly enjoy taking pictures with the 24-105. And it will hold its value very well too, always nice to know when times get hard!