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Entries in Sigma (2)

Thursday
Apr042013

Sigma 35mm f/1.4 A1 vs. Nikon 28mm f/1.8G

Sigma's brand new 35mm f/1.4 DG HSM A1, or Nikon's new-ish 28mm f/1.8G AF-S... which one is right for you?

These two prime lenses have similar focal-lengths, similar maximum apertures, and similar price-points. It's no wonder that I see them discussed and compared with each other on forums fairly often. Given $700-900 to spend on a fast, relatively-wide, prime lens, which do you get? First, let's take a look at a high-level specifications summary to get a feel for what they offer (clear winners highlighted in green):

To summarize: the Nikon is a bit wider, smaller, and lighter than the Sigma. It's also a bit slower (2/3rds of a stop), but it's a good deal less expensive as well.

Construction and Handling

The Sigma really outshines the Nikon in both construction and handling. When I first got my Nikon 28/1.8G, I was disappointed with the light, plastic feel of the lens. The focus ring feel light and cheap. It most certainly doesn't feel like a $700 prime lens should. Unlike the Nikon, Sigma uses a metal lens barrel with a very smooth, well-damped focus ring. It's also larger and heavier than the Nikon, which really give the Sigma a nice, high-quality feel. The flip-side of that is that the light weight and smaller size of the Nikon can certainly work to its advantage. I prefer to travel light, especially when hiking, where every single ounce really adds up. In that sort of situation, the Nikon would be my go-to lens.

Sigma 35mm f/1.4 A1 HSM DG

Focal Length

Focal lengths are tricky. What works perfectly for one photographer may feel completely wrong for another. To that effect, I've created two GIFs, below, which help to illustrate the difference in focal lengths. Please note that these comparisons are for the field-of-view on full-frame / FX cameras.

Focal Length Comparison: Sigma 35mm f/1.4 A1 vs. Nikon 28mm f/1.8G (16:9 crop)

Focal Length Comparison: Sigma 35mm f/1.4 A1 vs. Nikon 28mm f/1.8G

As you can see, the fields of view these lenses provide are actually quite similar. The Nikon may be slightly better suited towards landscape photos, and the Sigma might be a bit better suited for things like portraits and street photogoraphy. However, I like to challenge these sorts of assumptions, and I really think that either lens could be excellent for landscape, street, travel, and most other general types of photography - when placed in the right hands, of course. To give you an example, below is a landscape photo taken with the Sigma 35/1.4, and an environmental portrait taken with the Nikon 28/1.8.

Yosemite Falls (Sigma 35mm f/1.4 A1, landscape)

"Sailing, J24, Boston Harbor" (Nikon 28mm f/1.8G, environmental portrait)

Optical Quality

I don't have the right resources or knowledge to do a full optical assessment of both lenses. The general consensus across the web is that the Sigma is the new resolution benchmark to beat. From what I've seen, I have to agree. It's pretty astonishing in terms of center resolution and sharpness.

That said, the Nikon is nearly as good as the Sigma, and I have absolutely no complaints about its resolution or performance. If you're eager to look at some charts and numbers, the brilliant folks at Photozone.de have reviewed both lenes:

As you can see, the resolution numbers are quite similar. In terms of flare-resistance, both lenses performed very, very well during testing. I didn't have any issues with flare, even with the sun in the frame. It appears that Sigma's multi-coatings are beginning to rival Nikon's expensive "Nano-Crystal" coatings.

In short: both lenses are optically excellent.

Bokeh

I enjoy bokeh (out-of-focus blur) as much as the next guy, but I tend not to obsess over it. In this case, the Sigma wins out over the Nikon 28mm f/1.8G. This is simply due to the slightly longer focal-length and faster aperture, which just makes it more "bokeh-rific" than the Nikon (given the same subject at the same distance). Nevertheless, the Nikon's bokeh is pleasing and soft in certain situations, and about as strong as one might expect from any 28/1.8.

Autofocus

Both lenses feature fast, quiet, ultrasonic motors. I've encountered reports of the Nikon 28/1.8 having some focus-shift issues at different apertures (in-focus at f/1.8 may be out-of-focus at f/5.6). I've thoroughly tested my copy, and have had no such problems. There is some noticeable field curvature that one must be aware of, but that's expected of a moderately wide, fast lens. I didn't notice any field curvature with the Sigma.

As far as accuracy is concerned, both lenses are very accurate. Over the course of my week shooting with the Sigma, I only experienced one hiccup and missed-shot due to an AF problem. This was while using the extreme, center-bottom focus point. Some users have reported problems with the Sigma on the D800 when using the extreme outer focus points, but other than my one missed shot, I didn't have any issues. In fact, I also missed a shot in a similar situation with the Nikon during the same time period. Overall, I'd say that these lenses are about equal when it comes to AF performance and accuracy. Neither one is absolutely perfect, but they're not terrible either. In fact, they're both quite good.

Sample Images

I've been taking photos with the Nikon 28/1.8G for nearly a year now, so I've had time to amass a number of sample images that I'm very happy with. Unfortunately I only had the Sigma 35/1.4 for less than a week, since I rented it from the wonderful people over at LensRentals.com. Nevertheless, I managed to get a handful of images that I'm content to display.

"Port Tack, Boston Harbor" (Nikon 28mm f/1.8G)

"Sunset, Delicate Arch" (Nikon 28mm f/1.8G)

"Untitled" (Nikon 28mm f/1.8G)

"Wine Tasting, Napa" (Sigma 35mm f/1.4 A1)

"Summit Celebration" (Sigma 35mm f/1.4 A1)

"Tunnel View, Yosemite" (Sigma 35mm f/1.4 A1)

Summary & Conclusion

You really can't go wrong with either of these lenses. If cost, weight, and build quality are of negligible concern, then the decision could boil down to just one very subjective factor: focal-length. It really all comes down to the photographer's preference. Gary Winogrand famously used a 28mm lens for most of his street photography, but Henri Cartier-Bresson shot primarily with a 35mm.

For landscapes, I usually reach for a zoom (typically the 17-35/2.8 or 24-120/4) so that I can compose more precisely. For me, primes are more useful for travel, street, and portrait photography. Because of this, I find the slightly tighter focal length of the Sigma more appealing for general use. I also prefer the heavier and more solid construction of the Sigma over the Nikon. Conversely, I can see myself reaching for the Nikon when traveling light, like when hiking, where every ounce really counts. Other photographers might prefer working with primes for landscape photography, where the 28mm might be more appropriate than the 35mm.

If you're having a hard time deciding, I suggest renting these lenses from LensRentals.com before you choose. Or, you might try scotch-taping your zoom lens at each focal-length for a few days. It'll quickly become apparent which one you prefer.

Sigma 35/1.4 Pros

  • outstanding optical quality
  • 2/3rds of a stop faster than the Nikon
  • robust construction
  • nice, normal-wide field-of-view on FX
  • on DX it yields a "normal" 50mm equivalent field-of-view

Sigma 35/1.4 Cons

  • heavy
  • more expensive than the Nikon
  • no rear dust gasket/seal on mount

Nikon 28/1.8 Pros

  • outstanding optical quality
  • light and relatively compact design
  • nice, moderate-wide field-of-view on FX
  • less expensive than the Sigma
  • has rear dust gasket/seal on mout

Nikon 28/1.8 Cons

  • 2/3rds of a stop slower than the Sigma
  • cheap-feeling construction
  • on DX it yields a slightly strange 42mm field-of-view
Wednesday
Jul132011

Nikon 16-85 VR vs. Sigma 17-50 f/2.8 OS

Introduction

I've now owned Nikon's elaborately named "AF-S DX NIKKOR 16-85mm f/3.5-5.6G ED VR" lens for well over two years, and I'm incredibly happy with it. The excellent focal range makes it a superb walk-around lens. The 16mm wide-end is really something special on a "normal" range DX zoom, since most only go as wide as 18mm. Its superb sharpness when combined with those extra 2mm make for a very capable landscape lens. The brilliant optical stabilization system (Nikon's VR) makes getting hand-held low-light shots a breeze.

All of these characteristics make it an absolutely oustanding lens, especially for casual travelers. Photographing the interior of a dimly-lit cathedral? No problem: the 16mm wide end and VR stabilization make it a breeze. Want to capture the some of the exterior architectural details? Again, no big deal: the 85mm long end and superb sharpness can make it happen.

These features all add up to mean that it has been my primary travel and walk-around lens ever since I purchased it back in 2009. Many of the most viewed images in my portfolio have been taken with it:

Underground RailBoston Celtics

Waiting for the Red Line

Harry Elkins Widener

So, what is there to complain about? Not much, but I've always wanted something that's a bit faster. Constant fast-aperture "normal" zoom lenses are great for subject isolation at events like weddings, and their focal length coverage means that they're also handy all sorts of other things (including landscapes). They can also make for excellent travel lenses. One can easily go from shooting serene landscapes (stopped-down a bit at the wide-end), to beautiful portraits (wide-open at the long end) without having to swap lenses.

Nikon makes a well-reviewed 17-55mm f/2.8 zoom, but it lacks VR stabilization and is quite expensive (around $1500 at the time of this article's publication). Fortuantely, Sigma has recently released the stabilized "17-50mm f/2.8 EX DC OS HSM". At $670, it's comparatively priced to Nikon's 16-85 VR which sells for $650. The Sigma gives up 1mm on the wide end and 35mm on the long end, but makes up for it with an f/2.8 constant fast aperture. It's also worth noting that the Sigma has a more common 77mm filter thread, while the Nikon 16-85 uses 67mm filters.

Photozone.de has excellent technical reviews of both of these lenses. You can compare the resolution, distortion, abberations, bokeh, and other factors at the links below:

On paper the 16-85 VR is a bit sharper than the 17-50 OS when stopped down to their sharpest settings (f/8.0 and f/5.6, respectively). The 17-50 is actually quite sharp in the center when wide-open, which is great news for the casual portrait photographer. But the real question is, how do they stack up against each other, image-for-image? Let's find out.

Field of View

Below are some GIF images which compare the lenses at their different settings.

16-85 vs. 17-50 @ widest focal lengths

16-85 vs. 17-50 @ widest focal lengths

16-85 vs. 17-50 @ longest focal lengths (and 50mm)

As you can see, the 16-85 VR has a significantly wider field-of-view than the 17-50 OS. The difference is so large, in fact, that I believe the focal length of the Sigma is more like 18mm. That's quite disappointing. Of course, it also has significantly less reach on the long end, but that's expected. The Nikon most certainly wins here.

Sharpness

Time for some 100% crops. Center first, at their widest focal lengths and sharpest apertures.

16-85 VR @ 16mm, f/8.0 (center crop)17-50 OS @ 17mm, f/5.6 (center crop)The 17-50 is most certainly sharper in the center at 17mm. What about at the extreme edges?

16-85 VR @ 16mm, f/8.0 (corner crop)17-50 OS @ 17mm, f/5.6 (corner crop)The Sigma loses this battle. But what if we stop it down to f/8.0?

17-50 OS @ 17mm, f/8.0 (corner crop)

Getting better... but still not as good as the Nikon. At 50mm these lenses look virtually identical in the center. However, again, the Sigma loses sharpness in the very extreme corners. It's worth noting that only the most extreme corners are problematic with the Sigma. The non-corner edges look quite good, and the average sharpness across the frame is outstanding.

Verdict? This one is a draw. It comes down to this: do you prefer the Nikon's overall sharpness consistency over the Sigma's slightly sharper center and slightly worse extreme corners?

Aperture

One advantage that the 17-50 OS does have, however is the f/2.8 constant aperture. This can make for some pretty decent portraits at (or around) 50mm.

17-50 OS @ 45mm, f/2.8

The above photo is cropped a bit. If I had been standing a bit closer and had framed it properly, the background would look much more bokeh-licious (more blurry). Here's a 100% crop:

17-50 OS @ 45mm, f/2.8 (center crop)

Sharp, and very nice. For comparison, I took this portrait a few years ago right after I got my 16-85 VR:

16-85 VR @ 85mm, f/5.6Also very sharp, and actually it's quite good. I had to stand further back and ended up with a tighter framing since I was shooting at 85mm. Both lenses do well here, but I'll give the edge to the Sigma since it has the faster aperture and a creamier look. I wish I had time during this review to take some better portraits. I may update this section in the future if I come up with anything better.

Conclusions

I want to love the 17-50 OS, but it just leaves a bit too much to be desired. Yes, the f/2.8 aperture opens up some great portrait options when used as a casual walk-around lens. The major downside for me is that the 17mm wide end is just too restrictive when compared to the 16-85 VR. That extra little bit makes a huge difference. The Sigma also has a few funny quirks: the zoom ring turns the "wrong" way compared to Nikon lenses, which is rather annoying. The OS works well, but seems to consume battery at a slightly faster rate than the 16-85 VR.

Sigma 17-50 f/2.8 OS PROS

  • fast aperture (excellent in low-light)
  • good construction (on par with the Nikon)
  • excellent sharpness stopped-down (except the extreme corners)
  • excellent center sharpness wide-open
  • OS works well
  • standard 77mm filter size

Sigma 17-50 f/2.8 OS CONS

  • wider would be better (17mm seems more like 18mm)
  • zoom action turns in the wrong direction (for Nikon users, it's hard to get used to)
  • no weather-sealing (missing the butt-gasket, too)
  • larger and heavier than the Nikon
  • focus ring turns in AF mode (make sure those fingers are out of the way!)

Nikon 16-85 VR PROS

  • excellent focal length range (16mm is wide)
  • good construction
  • excellent overall sharpness, especially in the corners
  • VR works well
  • lighter and smaller than the Sigma

Nikon 16-85 VR CONS

  • slow aperture, especially at maximum zoom (bad in low-light)
  • non-standard 67mm filter size
  • no weather-sealing (although it has a butt-gasket to keep moisture from the lens mount area)

What do I really want in a fast-aperture DX "normal" zoom? A 16mm wide-end is a must. Excellent sharpness across the frame is a must as well. Finally, either a slightly longer-than-normal focal length (70mm on the long end) with a moderately fast aperture, or a very fast aperture and a shorter focal length (f/2 and 40mm).

For me, and I suspect for many others, either of these imaginary specs would be perfect:

  • 16-70 f/3.5 (stabilized)
  • 16-40 f/2 (stabilized)

If this rumor has any truth to it, we all may be in luck... but for now I'll probably stick with the 16-85 VR.

Full-Sized Sample Images

I'll leave you with one final image, taken with the Sigma @ 50mm, f/4.0:

Busy Bee