Despite its heft, size, and even cartoonishly disproportionate appearance, the Nikon 180mm f/2.8 AI-s ED is an odd, yet intriguing lens in use. It is one of the few hand-holdable, long, and FAST prime lenses that I know of, especially those made by Nikon (the only other one out there is the autofocus version of this lens!). What usually comes to mind for nowadays’ fast telephotos are the bulky 200mm f/2’s, the monster 300mm f/2.8’s, and even the gargantuan 400mm f/2.8’s. Though these lenses are indeed fast and long, they are far from being walk-around lenses; the main (if only) times they will be seen deployed in the field is on a monopod or tripod. The cost is nothing to sneeze at either, google any of these focal lengths and apertures and you will find lenses in the multi-thousands of dollars, even used. Though the 180mm is “only” an f/2.8, it is still very, very fast for its focal length.

But what’s the point of using a 180mm fast prime anyway when most all super-zoom lenses go to 200mm and sometimes beyond? Well, besides taking advantage of the inherent feel of shooting a prime, by “zooming” with the feet to create different perspectives and compositions, there are other key points to consider. A couple minor ones first: usually when one spends the same amount of money on a prime as a zoom, the prime will almost always outperform the zoom lens at the equivalent focal lengths (however, there are always exceptions to every rule). Also, prime lenses tend to have less glass elements than their zoom counterparts—this usually means more light can be transmitted through the lens, and there are less chances for architectural-photography-degrading distortion. For the big point though, with the fast f/2.8 aperture (which is more than useful with this lens), the 180mm lets in four times as much light as even the fast Nikon 18-200mm f/3.5-5.6 VR at the same focal length. Even this point is multifaceted: 1. The 180mm can use a faster shutter speed in low light, stopping motion whereas the VR in the 18-200 merely keeps the optics steady. 2. On average, the ISO values in shots will be around two stops lower when using the 180mm, a key advantage in controlling pixel-level noise (for instance, the difference between shooting at ISO 1600 and 6400—two stops difference—is extremely noticeable on high resolution cameras such as the NEX-7 even on the image level). 3. At a distance and at maximum apertures, the 180mm will always have a noticeably shallower depth of field (the distance perpendicular to the lens that is in focus), which comes in handy to separate subjects from the fore/background. Just some numbers for you to crunch: on an APS-C sensor using the 180mm focal length, the depth of field when focused on an object 50 feet away at f/2.8 is 2.63 feet. At f/5.6? 5.27 feet. Though the difference may seem small, take note that the effect of the larger aperture also influences just how far out of focus the fore/background is as it moves away from the subject. It can mean the difference between seeing nothing but a blur behind the subject, or having a distracting background. This effect is shown below. It is important to mention that as the distance to the camera decreases, the depth of field becomes so shallow on both lenses that the differences start to go away.

Now that that’s out of the way, let’s move on to the review!

Specifications

Full Title: Nikon Nikkor 180mm 180mm 1:2.8 AI-s ED

Dimensions: 3.1 inches in diameter, 5.4 inches long, with a weight of 28 ounces (a full pound heavier than the camera itself)

Close Focus: Marked at 6 feet/1.8 meters, but you can get a tad closer. Do not treat this lens as a macro lens.

Miscellaneous: 9 straight-bladed aperture stopping down to a helpful f/32 (for longer exposures/increased depth of field), 72mm filter thread (metal), built-in telescoping lens hood (very handy for keeping harsh light from bouncing off the front element), one big element of ED glass that is effective in reducing chromatic aberrations (discussed later). Also, the lens focuses a little past infinity (with a hard stop at its end) due to the nature of the ED element, which performs differently as temperature changes.

The “Feel”

Unlike the deceptively awkward dimensions of the 105mm f/1.8 AI-s, which was actually very balanced and comfortable to use, the 180mm is very noticeably approaching the limit of length and weight that should be mounted onto a NEX-7 for hand-held use. Any heavier, the whole kit would weigh down the neck, and would eventually be too heavy to hold up for extended periods of time. Any longer (focal length wise), and acquiring critical focus with the manual focus zoom-in feature would be accomplishable only by a surgeon’s hands. Like I said, this set-up is approaching these limits, but is not there yet. The whole kit can (and does) hang from the neck for a long time, and keeping it up to the face isn’t tiresome. With good technique, critical focus is regularly nailed via zoom-in.

The construction of the 180mm f/2.8 is typical of Nikkor AI-s lenses, which have been previously described by others to no end as the pinnacle of lens craftsmanship. Everything, save for the glass and paint in the engravings, is metal. Everything. The mount, the barrel, the hood, the filter threads, you name it. Though I would hate to drop the almost two pounds of this on anything (or anybody), I’m sure whatever it hits would be in much worse shape than the lens.

The focus on my copy, which turns a long 180 degrees (great for precise focusing, bad for rapid focus acquisition), is buttery-smooth and evenly damped throughout the range, surprising given how much glass and metal is being moved around as it turns!

Performance

Summary

The Nikon 180mm f/2.8 AI-s ED is a lens that was designed for large aperture (f/2.8-4) usage. It performs admirably on almost all fronts, with no glaring negatives to tarnish its reputation. If you need the 180mm focal length (270mm equivalent field of view compared with a full-frame sensor camera) and fast aperture to benefit your photography, go ahead and hunt down a copy. I got mine for just over $375; copies in excellent or mint shape are more expensive, while “beaters” (cosmetically ugly but optically functional lenses) should be a little less. However, if you find yourself happy with your 18-200 superzoom, even with the five-times-as-slow SEL18200 on your NEX, you may want to pass; the Nikon is noticeably heavier (by 10 ounces), and obviously is manual-focus only. That said, for close-up sports, headshots, and shallow depth of field photos, this is definitely a lens to consider.

Sharpness

Though sharpness is supposed to be only a small factor in a lens’ performance, many feel it is the most important. I personally fall somewhere in the middle. I love seeing pixel-level sharpness, but it isn’t terribly important that all my shots are sharp when viewing at 100%. With that in mind, I have found the 180mm to have odd performance characteristics with regards to sharpness. For these tests the camera was placed on a tripod, and the exposures were tripped with a remote release.

Regardless, let’s have a look by aperture, first up are center crops:

When I look at these crops I have to wonder what is going on. There are some odd exposure differences at f/2.8 and f/32, for starters. At f/2.8, there is plenty of detail, though it is covered due to some spherical aberration. What is strange though, from f/4 to f/11 I can’t notice any difference in sharpness (contrast has improved from f/2.8), save for comparing f/4 and f/11 at 300% (which is just impractical). Finally by f/16 on, diffraction sets in. By f/32, diffraction strikes with a vengeance, pixel-level detail and contrast are completely obliterated. These results may seem less sharp than the tests in my 105mm f/1.8 review, but remember, on those tests the chart was a smaller chart printed at a much lower resolution. In that review the individual printed dots were actually being out-resolved.

Now let’s look at corner crops, here is where I really have to start thinking about what is happening with this lens:

APS-C sensors enjoy something of a “sweet-spot” advantage when using full-frame designed glass when it comes to corner performance, as the sensor is really using just more of the center portion of the lens. This lens is no exception, but what surprises me is just how good the corners are even wide open. There is absolutely ZERO smearing. At f/4, sharpness and contrast has improved some. From f/5.6 to f/11 the corners are optimum, and diffraction sets in this time noticeably at f/16 on. By f/32, detail and contrast are completely gone. So getting back to wide open performance, I’ve already mentioned the “sweet spot” advantage, but there should at least be some corner smearing…right? Queue speculation: this lens has a contant “aperture” near the rear of the lens assembly. This fully circular ring could be serving to act as a “stopped down” aperture, in this instance right at f/2.8. Perhaps if this feature wasn’t in the lens the actual aperture could have been wider? See below shot to see what I mean.

Sharpness at Infinity

Just to confirm that it may be the chart giving the appearance of reduced sharpness from the last lens test, I took the lens out to get a few infinity-focused shots of the moon at various apertures. Interestingly enough, the captures followed the same pattern as in the chart tests. All of the shots (taken from f/2.8 to f/11) looked the same as the shot below. The only difference was reduced contrast at f/2.8.

Sharpness at “Macro”

As I mentioned earlier in the review, this lens doesn’t focus close enough to even be considered as a “serious” macro lens. That said, performance at this range of about 6 feet can be important to those who need it. In this set-up shot below (which will also be used to assess highlight bokeh), the optimum aperture up close is still f/5.6, diffraction is slightly noticeable at f/8, but it almost looks as good.

And a 100% crop from the leaves just off the center of the tin:

Bokeh

“Bokeh” is an artistic term of Japanese origin for the character of anything in the image that is not in focus. Typically, smooth bokeh, where out of focus objects and highlights seem to “melt” into the background, is favorable. In regards to this lens, bokeh performance is great where it was designed to be used, from f/2.8-4. First, some samples, then some analyzing. Here is the set-up:

First, fore/background bokeh (these are NOT 100% crops):

In these sample shots, the backgrounds have a characteristic “smooth” blur quality, while the immediate foreground bokeh (closest to the altoids box) is also pretty smooth. However, as things get closer to the camera, bokeh becomes more “busy”, I see some doubling rather than blurring at the larger apertures. Overall the bokeh is very nice, so long as close foreground objects are not in the frame. Avoid these if you can help it.

Now let’s look at how this lens handles out-focus-highlights, with close (almost 100%) crops taken from the decorative item in the close-focus shot:

As far as the handling of out of focus highlights, the 180mm f/2.8 does very well at f/2.8-4: highlights do not have defined edges, and are clean throughout the highlight. However, from f/5.6 on, the borders of the highlights start becoming noticeable, and odd artifacts start showing up that are distracting. However, this is looking very closely. Unless you print very, very large, this highlight degradation will not be noticeable. Now, time for a “real-world” shot showing how bokeh may look like in actual photographs:

Purple Fringing

A form of chromatic abberation (a type of distortion where certain colors do not hit the image sensor at the same convergence point), purple fringing is typically seen in fast lenses at their wider apertures when shooting scenes of contrast, such as branches against sky. Though purple fringing can be cleaned up very well in post processing nowadays (see my detailed post on that here), it is still an important point to take in consideration if one either doesn’t have the time to post process, or has purple objects in the frame that does not want to be desaturated. The Extra-low Dispersion element that I specified above does its magic here. I had to go well out of my way to get half-way noticeable purple fringing, even wide-open! Even the most fringing I could get is correctable. See below for some examples, all of these are handheld, so focus isn’t critically nailed:

Personally I’m still amazed with the way Lightroom 4.1 can handle purple fringing, it makes any fast prime infinitely more useable in more conditions. If you couldn’t already tell, the ED element in the 180mm f/2.8 keeps purple fringing to a very low level. If you don’t mind a bit of post-processing in extreme contrast situations, just shoot this baby wide open all the time.

Flare

To my knowledge, this Nikkor (along with all AI-s Nikkors) is multi-coated to help guard against lens flare resulting from internal reflections from strong light sources. The coatings in this lens appear to work extremely well. In an attempt to exacerbate the problem, I shot a couple pictures stopped down (the aperture doesn’t affect flare in this instance) towards the sun without the hood extended. WARNING: the only reason I could get these shots is that the NEX-7 uses an electronic viewfinder. If you try to do the same on a DSLR with an optical viewfinder you may blind yourself, so be careful! In this first shot, with the sun just barely out of the frame, I see no obvious reflections from the elements themselves, there is a faint (but large) blob. Veiling flare also isn’t very apparent:

With the sun in the image, the lens does just fine:

And when the sun is centered?

Rest assured that whenever a strong light source is near or in the frame with the 180mm f/2.8, it won’t cause too much trouble.

Vignetting

Vignetting, to put it simply, are darkened corners as a result of shooting near the wide open aperture. One of the other sweet spot advantages when using a “full frame” lens on an APS-C sensor is the relative absence of vignetting. This applies to the 180mm f/2.8 wide open and at any stopped-down aperture. There is no noticeable vignetting in any shots.

Distortion

After overlaying multiple different gridlines on my test chart pictures, I still cannot find any signs of distortion. Though no lens is perfectly straight everywhere, the distortion in this lens is so small that it isn’t worth correcting, given you can even find any.

Now let’s hit the old recap.

Pros and Cons

Pros

• Superb build quality and mechanical performance in all aspects imaginable
• Great performance wide-open, which is four times faster than most zooms at 180mm
• Good shallow depth of field wide open for subject isolation, second only to the bulky and expensive 200mm f/2
• Critical sharpness at all focus distances is at f/5.6, two to four times as fast as the typical f/8-f/11 of zooms. However, f/4 is almost as good! The only limit to image quality at f/2.8 is spherical abberation, but even at this aperture the corners are just fine.
• Background and immediate foreground bokeh is very smooth, large aperture highlights are handled very well
• Purple fringing isn’t an issue wide open with 15 seconds of post-processing. In most circumstances it still isn’t a big deal even without editing.
• Flare is handled well with only one faint (but large) reflection blob
• There is no vignetting to worry about
• There is no distortion
• Lens is just as fast as the professional 70-200 f/2.8 zooms, but is much cheaper, and probably lets in more light due to having fewer elements

Cons

• It is relatively heavy, approaching the limit of comfortable and reliable hand-held shooting
• Close foreground bokeh is busy and distracting
• Manual focus only (in case you had forgotten)

The Bottom Line

This is a special purpose lens that is good at what it does shooting at the larger apertures. If you are proficient at manual focus with the excellent peaking and manual focus zoom-in features on the NEX series and other mirrorless cameras, then the 180mm f/2.8 AI-s ED may be your next lens for close-range sports photos, headshots, and shallow depth of field work. Funny enough, I haven’t been able to shoot any sports or close-ups with this lens yet, but I know it will be perfect for softball where my 300mm f/2.8 is too long. I have also read that this lens is a stunner for astrophotography. Apart from my brief moon testing, I have yet to give that a try, so I can’t particularly comment there. With that, here are just a few more “real-world” pictures that I have enjoyed with this lens so far:

As always guys, have a great one, and thanks for dropping by. 🙂