I’m super excited to announce that I will be making a presentation at the CanvasPop digs in Ottawa on January 24th 2012. The event is totally free and you’ll get to see my presentation on travel photography then hang out with a bunch of cool people and Ottawa creatives at the awesome CanvasPop HQ. Don’t miss it, space is limited to the first 40 people who respond. Get in touch with Heather at the address below.

This is a long overdue review that I have had to delay for a number of months due to numerous competing priorities, but I am happy to finally be able to present it to you. First, I’d like to thank Gentec International (the Canadian supplier of several photography brands, including Sigma) for making this possibly by providing me with the Sigma 24-70 lens so I can try it out first hand and then present you with my thoughts and opinions.

Now this is by no means supposed to be a quantitative analysis with MTF charts and reports. There are several sources out there on the net that are better equipped and qualified to provide you with those. What I aim to do is offer a real world assessment following my testing on the field; something that MTF charts often fail to do.

The Bottom Line:

If you are interested in the bottom line, here it is: while this is not Sigma’s most stellar optical performer, there was not a single moment when I thought it couldn’t do the job (both from an optical and physical perspective). In the one-month period I got to try it, I took it on two consecutive assignments for editorial clients, where I relied on it almost exclusively and it didn’t let me down. In fact, I thought it was the best lens in my arsenal for the tasks at hand. The build, size, fast aperture and the fact it cost almost half of the price and is lighter than its Nikon equivalent make it a very attractive proposition. For me the extra 4mm at the wide end alone, make it more appealing than my 28-70.

The Specs and Handling:

As usual, Sigma has here a very solidly built zoom lens that really inspires confidence. While it is a fast zoom with a max aperture of 2.8, this lens is much more compact (less than 4 inches in length) and lighter than my old Nikon 28-70 f/2.8 (and incidentally than the newer 24-70 f/2.8). It still weighs in at 790g, but that’s significantly less than the 900g the Nikon throws around, which makes it a great companion for walk-around (I often feel my 28-70 is out to break my neck, I swear). The autofocus is very fast and quiet and accurate. The focus and zoom rings are very easy to locate and are nice and smooth. The minimum focusing distance is 38cm, which is considerably closer than my Nikon 28-70 and which comes in really handy at times. On the negative side, the lens sports a 82mm filter thread size, which I find quite annoying. This is a rather non-standard size, as most pro lenses tend to have a 77mm filter thread, meaning you would likely have to get a new set of filters for it. Good filters already don’t come cheap at 77mm, but at 82mm they are prohibitively expensive.

The Performance:

This area is where I was initially disappointed by the lens. I had previously read Darwin Wiggett’s review of the lens which demonstrates that in several instances it is clearly superior to the Canon counterpart. Therefore, my expectations were fairly high. Not owning that (or any) Canon lens, I couldn’t replicate what Darwin reported, but could only make a comparison to my venerable Nikon 28-70 f/2.8.

When it comes to sharpness, the Sigma image’s borders were very noticeably soft from f/2.8 all the way to f/8 at all focal lengths, but especially between 24 and 35mm. The borders are acceptably sharp from f/8 to f/11, until diffraction kicks in at f/16 or so, but they still remain under par on the sample I tried. The centre performance is very decent across the board. When it comes to vignetting, it is quite noticeable until f/4, when it starts to fade away (this is specially the case at 24mm, vignetting is barely noticeable at 70mm). That said, it is nothing that your RAW converter can’t take care of without a problem. The bokeh isn’t spectacular and is somewhat rough on the edges, though it isn’t a deal breaker for me.

Despite these issues, when you look closer, the disappointment is not long lived. Is the Sigma 24-70 f/2.8 the best lens in this focal range? Probably not. If you are a pixel-peeper and/or edge-to-edge sharpness wide-open and stellar optical performance is what you need, this is not the lens for you [I will be reviewing the Sigma 85 f/1.4 and 70-200 f/2.8 in the future and they will rock you off your socks in that department). However, in my case, I find myself using this focal range in two possible ways:

- when shooting portraits I will often be shooting wide-open (or almost), and in this case, my subjects are often located somewhat centrally in the frame, such that corner optical performance is for all intents and purposes irrelevant;

- when shooting landscapes, I am likely to be shooting at f/11 or greater, such that the lens is in its optimal range, thus allowing me to obtain the edge-to-edge sharpness performance I need in these circumstances.

Therefore, for most uses, the lens will be more than adequate to deliver the desired results, both from a mechanical and optical standpoint, and the optical shortcomings will be merely an afterthought. The lens produces very pleasant images with crisp contrast and a slightly warmer tones than my Nikon (I incidentally tend to prefer the warmer tones). As I said above, not once during the assignments with the Sigma 24-70 did I not think it could do the job. So all in all, if you need a lens in this focal range with an f/2.8 max aperture and budget is a consideration, then this lens merits your attention. At roughly $1000 less than its Nikon and Canon counterparts its price/performance ratio is rather appealing.

To sum up:

Cons:

- Subpar optical performance wide-open

- Unusual 82 mm filter thread

Pros:

- Beautiful and solid construction

- Accurate and fast autofocus

- Small and lighter than the competition

- Fast aperture zoom at a very reasonable price.

I have been waiting for years to make these images. Literally. I had the images in my mind’s eye. I knew (more or less) exactly what I wanted. I knew the conditions that I needed to make it a reality. Unfortunately, when these conditions materialized in the last few years, I was never in a position to take advantage of them. Until the end of December that is. Finally! Wet snow, a cold day and TIME! I still think they need some work. Amanda and I have some interesting ideas for them…more to come on that later.

This is a photomerge of two images taken with a 24mm Tilt-Shift lens

If you still insist on going out and shooting, here are a couple posts from a few years ago about winter shooting: Number 1 and Number 2.