|SigmaUser Review - 15-30mm EX DG f3.5-4.5|
|Written by Julian Ashbourn|
|Friday, 30 January 2009 22:55|
SigmaUsers are welcome to submit reviews of the lenses as articles; these represent the opinions and verdicts of photographers from all backgrounds. Julian Ashbourn has provided this one for the established Sigma 15-30 EX DG.
The Sigma 15-30mm f3.5-4.5 EX DG has been around for a while now and some might think of it as an 'old' lens. Furthermore, its physical design may be perceived by some as a little ungainly, although others might welcome the sheer physical presence of this relatively large lens. However, this is a lens which has some special qualities of its own, as we shall discover.
The lens has a fixed petal type lens hood which, in addition to performing its primary function, helps to protect the rather bulbous front element. A supplementary sleeve may be fitted over the hood in order to provide an attachment for the supplied lens cap. It is also capable of accepting an 82mm filter. The sleeve may be left in place when fitted to an SD14 with its 1.7 times crop factor as there is no discernable vignetting when used in this manner. This may sound like a rather complicated arrangement but, in practice, it works very well. Being around 132 mm in length and weighing in at 620 grams, the lens balances quite nicely on an SD14 body, making for a comfortable hand held assemblage. The large focus ring mat be slid forwards or backwards upon the lens barrel in order to engage or disengage manual focus. When disengaged, one may support the lens comfortably via the focus ring without danger of stressing the auto-focus mechanism. Some find this idea a little messy, but it works well in practice and it is surely nice to have the option.
The auto-focus mechanism on the 15-30mm cannot really be described as quiet, but it is not unduly intrusive either, with a pleasant enough sound. More importantly for some, the focus is relatively fast and decisive, locking on to a given scene, even in less than ideal lighting conditions. If one prefers to use manual focus, the mechanism is smooth and precise via the large focus ring. Interestingly, with the zoom set to 30mm, it is possible to undertake some quite close focus work with this lens should the need arise. This factor could prove invaluable to landscape photographers who may capture both large scale vistas and relatively close detail without changing lens.
In the context of image quality, this lens really shines and, in certain areas, excels. Geometric distortion is very well controlled for all practical purposes. Landscape photographers, with the camera properly aligned with the horizon, will be able to produce some beautiful results with little or no discernable distortion. Those who wish to deliberately introduce distortion for dramatic purposes, may of course experiment with various camera angles in order to achieve such an end, but the Sigma 15-30mm does not impose such a situation upon the photographer.
Used with a little care, some beautiful wide panoramas may be produced in which it is not at all obvious that a wide angle lens has been used. That is a remarkable attribute for a lens in this class. In terms of resolution, the lens is sharp and clear without producing the rather artificial sort of enhanced sharpness that some lenses are guilty of. From around f5.6 onwards, it will produce images as sharp as you could wish for. It is also perfectly usable at the largest aperture of f3.5, providing a certain amount of versatility for the creative photographer.
In addition, and quite apart from, its specific resolution, this lens produces what I can best describe as an uncommon clarity of image. At any aperture, images have a smooth and unforced character to them which is most attractive. This will be of particular advantage to landscape and nature photographers who may capture all the detail they need without images becoming stark or too punchy. The other quite outstanding attribute of this lens is its colour neutrality which is quite excellent. Delicate tonal transitions and fundamental hues are reproduced faithfully. No more, no less. Furthermore, this seems to be the case under a variety of lighting conditions. In my experience, there are relatively few lenses, especially zoom lenses, which achieve this. But the Sigma 15-30mm does so. Assuming my example is typical, this quality alone places this lens in a somewhat elevated position, especially for natural world photographers, although portrait photographers may also appreciate this factor.
The subject of lens flare is invariably discussed in relation to wide-angle lenses, especially super wide angles such as this one. Remember, the 15-30mm is a full-frame lens, delivering a true 15mm on such a camera (around 25mm equivalent on an SD14). Under evaluation, admittedly on a mildly overcast day, the lens showed no tendency to flare. Of course, you can induce flare in almost any lens if you are either determined or careless enough to do so, but with the usual care and attention to detail, I would not expect this lens to be particularly troublesome in this area.
The Sigma 15-30mm EX DG lens may be regarded by some as an ugly duckling compared to some of the more recent designs. But those with such an opinion might usefully take another look. It is, in fact, a superbly comfortable lens to use, especially for those with larger hands and balances nicely on a Sigma SD14 body, as it would no doubt on various Nikon and Canon bodies. It is intuitive in use and capable of producing some truly excellent imagery, in some aspects, better than one might expect anywhere near this price point. It is compatible with both full frame and cropped sensors and is built to the usual robust Sigma EX standards. It may not be a new design, but it is currently still available and at a price well below its original level. More importantly, it is a lens of very distinct qualities, some of them elusive at any price. In conclusion, the 15-30mm EX DG is a classic lens, which you may still acquire new and at reasonable cost. Now there's a novelty.