This is a wide angle lens made by Canon compatible for use on both it's full frame and crop frame DSLR's. It should also be compatible with Canon's EOS M series with an adapter. The wide angle nature is maintained on full frame bodies, using the crop body you end with with a not so wide 25-56 range.
The 16-35 is a Canon L lens. This L represents the pinnacle of Canon's lenses and show they made for the best possible professional quality and comes sealed from dust and moisture when used with a professional body. It will require a filter to be added to be fully sealed against the elements as stated in the manual.
A constant maximum available aperture of 2.8 allows the lens to work in low light conditions throughout its focal range. And when this lens is used at smaller apertures you can expect pin sharp images from corner to corner.
The lens is supplied with a very wide petal shaped lens hood and with it on, there is a small amount of vignetting apparent in images shot at the wider lengths. This is easily adjusted for either with Canon's free DPP software or Adobe Photoshop.
I bought this lens whilst I still used a crop body and the large heavy 16-35 resulted in similar usable ranges to the 18-55mm lens. When I switched to a full frame, this definitely became a wide lens. At the 16mm end, I was surprised at the amount of view I could fit in, this also meant at the wide end, I am able to take fantastic indoor shots in tight spaces.
After studying the statistics of the photos I have taken with this lens, the majority fall in the 24-35 mm range. This means that I am not exploiting the whole reason of having a wide angle lens, to use it at the wide angle.
So why didn't I settle with the cheaper Canon 17-40 f4 L lens? The extra 1mm at the wide end makes a much greater difference than 5mm at the other. Also, I find I use this as an indoor lens quite often without a flash and the 2.8 aperture becomes an essential feature.
Let me further explain what I use this lens for. Obviously it is my go to choice when taking in landscape images, it is also useful for full body environmental portraits and the occasional distorted up close portraits of mostly animals.
I still find this the lens most often attached to my camera. It is simply the best wide angle lens made by Canon and I wouldn't replace it with the cheaper 17-40 f4, I feel I need the wider aperture more than the greater range. If you can stretch your budget for this L lens then get it for its great quality of build and performance. If you are unsure between this and the 17-40mm, the three factors you should consider are, can you afford it? Do you need a 2.8 apertures? Do you need the extra 5mm?
The original 16-35 f2.8 takes a 77mm filter, much like the 17-40, this means that if you already have filters for your other L lenses then they will go straight on- the new 16-35 annoyingly takes 82mm filters which are rarer and more expensive.
The old 16-35 f2.8 is a bad lens at f2.8, consider it a 16-35 f4 and you'll be happy, the coma and 'glow' at f2.8 make it unusable in my opinion, the new II version is clearly superior.
Compared for image quality they're all pretty much the same really, the new 16-35 taking the crown, the 17-40 doing comparatively well (except for the corners) and the old 16-35 coming in last.
I don't think i'd recommend the old 16-35, if you're on a budget get the 17-40, it's a stellar lens and unless you really need f2.8 it's a much better deal, and if you do need to shoot in really low light then there's always the 24 1.4 or the 24 2.8 IS
based on the feedback from comments I will add some more to this review. Please note that this review is for the old 16-35 not the new 16-35 II, you can't even buy the old lens anymore except on the used market. The lens is selling for around the same price as the new 17-40, so this review is meant to compare the two lenses and ultimately to dissuade people from thinking about purchasing that old lens. The truth is that wide angle zooms are hard to make, and it's only recently that good wide angle zooms have come on the market. You might be tempted by the f2.8 of the old lens, but very soon you'll realise the performance at 2.8 is terrible and you'll always be shooting at f4+, thus cancelling out the speed benefit of buying an 2.8 lens (if you want 2.8, either get prime lenses or get the new 16-35). Perhaps I got a duff copy, or perhaps it has just been knocked around too much- but eitherway given the choice between a brand new 17-40 which I would exhcnage if there was any problems, or a 15 year old 16-35 that I was stuck with for the same price, there would be no doubt which one i'd take.
hope this makes the review more in depth
This lens is part of my basic set-up for any job, I'm a professional photographer & while maybe it's not an essential lens, it's one I always like to have at hand.
This is an excellent super wide angle lens, great for landscapes, I often use it for wedding photographs that include a venue or large scene as a backdrop. I also use it regularly for wide photographs which feature large groups of people.
As with any L Series lens it is large & quite heavy, but no different from any other lens of equivalent build & image quality. This is without a doubt the best & most versatile wide angle lens in the Canon range. It handles very easily & is easy to use.
If you're only going to buy 1 lens, this likely isn't the one for you, it's not a hugely versatile lens & while it has several very distinct uses, it also has limitations - 35mm (the long end of this lens) is approximately what your eyes see. So if you bear that in mind uses for this lens are for your eyeline of wider, so really landscapes & architectural use. If you want a portrait lens you will need something longer.
The focusing is fast & accurate, with excellent ergonomics & build quality meaning the handling is always fast & efficient. The lens is weather sealed, but I always attach a 77mm filter to the front of any lens to protest it further. In my time I have dropped lenses & the filter has acted as a guard meaning I have yet to fatally damage a lens. Without the guard a drop on concrete could ruin this lens (you get a 12 month warranty with any Canon L Series lens as standard.
Not so relevant now as the £ is weaker, but if you're holidaying abroad, particularly in the Far East or North America, you will pick up any lens of this quality far cheaper buying there than here. The Canon warranties are global so it's irrelevant where you bought it.
The lens opens up to 2.8, giving you marvellous quality with beautiful blurred backgrounds, as you would expect with any L Series lens.
Some pro's complain of vignetting on the edge of the image with the L Series zooms, I personally have not experienced any major problems. If you're working on a non-full frame body (any Camera less than the 5D), you would not see any difference regardless.
It comes supplied with a lens hood & a soft pouch (which I personally never use). While this is a fantastic lens, arguably the 17-55mm is equally sharp (not to mention significantly cheaper). If you don't need the 2.8 aperture, there isn't a great deal of point in spending double the money on this lens. The 17-40mm is another alternative option if price is an issue.
Not an ideal walk around lens (unless you like landscapes or photographing buildings), but this is a necessary & valid part of any serious photographer's equipment kit.