With most things in photography, you can spend a little or you can spend a little more. This is especially true of lenses given the wide variety that is available from the various manufacturers. Sigma was the first with a "normal" 30mm fast prime for crop cameras, but was upstaged in the Nikon world by the Nikkor AF-S 35mm f/1.8 G, which was cheaper (a traditional Sigma virtue) and sharper, albeit with dodgey bokeh. Given that Sigma invented this category, the 30mm focal length was one of the first lenses that they returned to at the outset of the Global Vision refresh. As such, Sigma's response was something that fell into their "ART" lineup. It's very much the little brother to well-received full-frame 35mm lens, meaning that this is an upscale offering in the value-oriented APS-C category.
The build of this lens is representative of the refreshed Sigma Global Vision line-up. It's shed the drab matte appearance of the previous generation. The material is a glossy black that it has a deepness to it... there's depth to how the light falls off of the shell which gives the composite body a bit of an obsidian-like glassy sheen. The old lens had a very utilitarian appearance, but the new one is arguably more attractive than the comparable products in the Canon and Nikon lineups. Tolerances are tight and there isn't a trace of wobble anywhere in the lens. The focus ring turns with a smooth damped feeling that is in keeping with the best lenses out there. Focus operation is quick and silent thanks to the HSM mechanics, with no signs of AF hunting or hesitancy in moderately indoor light situations.
Compared to the first generation of this lens, the optical design of the ART lens is different. The optical elements are arranged in a similar manner to that of the 35mm DG lens, and the difference is apparent in the less prominent front glass element. Somewhat of a downside: this lens uses 62mm filters. It's not uncommon to find, but this is a somewhat oddball size.
This is a lens that would feel at home on cameras like the Canon EOS 70D, Nikon D7100 or Pentax K-3. It's not heavy by any means, but there is a denseness to it that makes it feel out of place on the smaller entry-level bodies. That doesn't mean that this lens isn't useful on a Canon EOS T5i/700D or a Nikon D5200, but the number of owners of those cameras who would opt for a lens like this is few as the cost of the 30mm is already a significant portion of the cost of the camera kit itself. However, for the enthusiast who has a lens collection that exceeds the value of his or her camera body, this is not an unaffordable item to acquire.
The previous version of this lens was received with mixed emotions by many. The size and virtue of a 30mm prime on the APS-C format was obvious to all, but the image quality outside of the center of the frame was lacking on the older 30mm f/1.4 EX DC HSM. If you didn't look too far into the corners, that didn't matter, but many people did. The bokeh on the older lens did have highlight fringing, but it wasn't harsh. However, given the overall optical qualities of that lens, the bokeh would have been better described as "smoothed-over" rather than "smooth."
The ART version of the 30mm is a different animal. Given that it shares a similar optical layout to the larger 35mm lens, it isn't surprising that it displays a similar virtues. The contrast and sharpness in the focus plain is fairly high, even at the larger apertures. The bokeh is smooth without appearing as though it was smeared, and the highlights with the lens wide-open aren't overly fringed or distorted. Geometric distortion is low, and vignetting is visible below f2.8, but is not objectionable. Like most primes of similar persuasion, the minimum focus distance is not not short enough to do any kind of meaningful close-up work. Here is what the bokeh looks like when focused at close range, approximately 2-3 feet:
|Nikon 35mm DX f/1.8|
Compared to all of the 35mm f/1.4 full frame lenses, the Sigma 30mm is cheaper, smaller and just as good on an APS-C body. There's a temptation for some to accumulate full frame lenses for an eventual jump to the larger format, but few ever do. In the meantime, those users are stuck with expensive and heavy lenses, often with mis-matched focal lengths in the case of zoom lenses.
Less expensive and more viable alternatives for the Nikon and Canon camps are the Canon EF 35mm f/2 USM IS and the Nikon AF-S 35mmf/1.8 DX G. All three lenses serve difference purposes, though. The Canon 35mm f/2 IS is the only one that has image stabilization, making it more suited for video work than the Sigma 30mm. However, the Canon is full frame, whereas the Sigma is not. In the Sigma's favor are the fact that it is both less expensive and that it offers that elusive extra stop of aperture opening.
The Nikon 35mm f/1.8DX is a budget lens; it offers an incredible amount of sharpness for a very reasonable price. However, it suffers from a harsh and busy bokeh. The Sigma is sharp and has excellent bokeh, but because it offers more, it also costs more. Though prime lens buyers will look at both, the truth is that there isn't much cause to cross-shop these lenses against one another.
Ignoring lenses of the similar focal lengths, perhaps the strongest competition for the Sigma 30mm f/1.4 DC ART is the proliferation and popularity of standard-zoom lenses. Almost all, with the exception of Sigma's own 18-35 f/1.8 DC HSM, are constant f/2.8 apertures or slower. For many people, the convenience of having a zoom lens outweights the creative possibilities of extremely shallow depth of field. For the majority of those people, spending $500-$700 for a quality lens is an expenditure that they would rather only do once. Hence the real competition for a lens like the Sigma 30mm.
The fact that it is a premium APS-C prime lens is a brave choice for Sigma. Nikon's 35mm f/1.8DX is one of their best selling lenses, but that's based partly on the fact that it's so inexpensive. The Nikon is a good second lens to a slow kit-zoom. In that regards, the Sigma 30mm is too, but the problem is that the pool of kit-zoom buyers who would reach for a premium prime over the inexpensive one is small. Optically, the Sigma is a good companion lens for something like the Sigma 17-50mm f/2.8 DC OS HSM, the Nikon 16-85mm f/3.5-5.6G ED VR AF-S DX, the Tamron SP AF 17-50mm f/2.8 XR Di-II VC LD or the Canon F-S 17-55mm f/2.8 IS USM. The problem, as outlined above, is that all of these stand-zooms make for good "walk-around" lenses are optically competent in their own right. The fact that Sigma 30mm falls right in the middle of the zoom ranges of these lenses means that you will fall into many situations where you could use one or the other, and usually it's the zoom that wins.
The problem with the "normal" 30mm APS-C/50mm full-frame field of view is that it looks merely "normal." You can open up the perspective with a wider lens, or you can compress the perspective by going longer. In other words, to make a 30/50mm lens stand out creatively, you have to work at it. Another way to be creative with a lens is to exercise control over the depth of field. In that regards, the Sigma 30mm f/1.4 DC HSM ART is solid offering in what is an emerging era of relatively affordable lenses that can be wide-open without regrets. A good-looking lens that produces good-looking images.
With thanks to Broadway Camera