"The nature of compromise is that you don't get everything you want" --Conrad Burns
What is it?
The Sigma 150-500mm f/5-6.3 is one of three Sigma telephoto zooms with reach out to 400mm or beyond (the other two are the 120-400mm f/4.5-5.6 and the "Bigma" 50-500mm f/4.5-6.3). Since these are relatively low-priced options for telephoto reach (US$999 to US$1700), they are somewhat popular with the budget conscious. The question is: what do you give up?
The optical formula is 21 elements in 15 lens groups, which puts this lens into the "very complex" range of lens designs. Three of them are SLD (Special Low Dispersion) elements. Super Multi Layer (SML) coating helps keep internal reflections to a minimum. Filter size is 86mm.
HSM refers to a built-in lens motor, much like AF-S, so this lens will work on all modern Nikon DSLRs (it won't work on a number of older film cameras, though). Optical stabilization is built in and features two modes, very similar to Nikon's older VR system. Sigma claims three to four stops of improvement.
The lens covers FX format, presenting a 5 to 16 degree angle of view (diagonally) on FX and a bit more than 3 to about 11 degrees on DX. Close focus is about 7'3" (2.2m), presenting a maximum magnification of 1:5.2. A removable rotating tripod mount is included, and the handle has finger cutouts for comfort while carrying. The lens has a focus scale, but no DOF or IR markings. An AF/M switch allows you to switch between autofocus and manual focus on the lens. At the minimum focal length, you can lock the lens with a switch so that it does not slide out to a longer focal length on its own, though I didn't find that my lens had the tendency to do that. There are 9 aperture blades. There is no dust/moisture protection built into the mount.
Sigma makes two HSM APO teleconverters that can be used with the lens: 1.4x and 2x. However, given the relatively small aperture of the lens, using them will put you beyond the autofocus capabilities of the camera. Thus, you'll have a 210-700mm or 300-1000mm manual focus lens using them. Also, you've already got 30 surface/air boundaries, and adding a teleconverter will add several more. I wouldn't expect sharp, high contrast images with the converters in place.
The lens is about 10" (252) in length without hood or zoom extension. It's almost 16" fully extended. Weight is about 4 pounds, 3 ounces (1910g). Some of the weight reduction is due to the use of polycarbonate in the lens barrel and other pieces.
The lens comes with a large reversible bayonet hood and soft carrying case for US$1470 (MSRP). Sigma's page for the lens is here.
How's it Handle?
The 150-500mm is a quite manageable lens for getting to 500mm. You don't need a huge case or a lot of muscle to carry it. In many ways, it reminds me of a modernized 500mm f/7.2, a lens Sigma used to make that was also a popular budget way to 500mm. One temptation (don't) is that it is hand holdable. Indeed, you can try that, but most people aren't going to be up to steadying it well enough hand held even with the OS system active. Even I had a hard time with that (see below). Ironically, the lighter weight of the lens may not give you enough mass for great hand holding because the temptation is to hold the whole thing too close to the body and well away from what will be the pivot point of lens movement. With a D3x and a great deal of care I was able to get a few reasonable shots hand held in Denali, but I also had a lot of non-keepers (again, see below). So I would still recommend that you go to a tripod and gimbal head with this long a lens.
The focus ring is closest to the body and smooth for a budget lens. Focus goes from near to far in about a 60° turn of the ring, which puts it in a pocket between too short a throw that doesn't allow much discrete focus tuning and too long a throw that forces the hand through awkward position changes. The zoom ring on my sample was also smooth, though stiff. Frankly, that's better than being non-stiff, which leads to zoom creep as you're carrying (though the lens has a lock to prevent this should you encounter it). The zoom range goes from minimum to maximum in about 45 degrees, which also feels about right.
The removable tripod mount is nicely done, and easy to tighten down into a very solid platform. You can still get some lens movement if you don't lock it down really tight, and it's not perfect, but in practice it's slightly better than what Nikon gives you on much more expensive lenses.
The lens balances okay on low-end DX bodies, but is a little back heavy on the heavier DSLR bodies (i.e. center of gravity of the lens/FX combination is going to be behind where you think it ought to be, which is part of that hand-holding issue). But again, you probably shouldn't be counting on hand holding this lens.
How's it Perform?
Sigma's MTF charts look promising for this lens, especially at 500mm. Indeed, the charts seem to indicate that it might perform better at 500mm than at 150mm. It does not. My short answer is this: Sigma's built a respectable lens that performs quite well out to about 400mm. To use my terminology (superb, excellent, very good, good, fair, poor), I'd say the central area at 400mm is near excellent, but falls to only good, maybe even all the way to fair, at 500mm. My equivocation has a bit to do with how you handle the lens. Handheld at 500mm f/6.3 is likely going to be only fair in my experience. With all your t's crossed and i's dotted in your support system and handling, you should get good results at 500mm and f/8. The lens achieves its best results at f/8 for most focal lengths, except 150mm where you need to stop to f/11 to hit maximum definition. Surprisingly, the corner performance is not terribly behind the central performance at 500mm, though it does lag considerably in the mid-range focal lengths.
Let's examine a bit of what I mean in detail. Here's a D300 at 500mm f/6.3 and 1/400 handheld. First the full image:
Now the 100% view at the center:
The actual focus point appears to be right at where the antlers intersect the head, so it's not focus that's the issue here, it's the general softness at 500mm f/6.3 coupled with not managing to quite nail the hand hold, despite OS.
So let's put the lens on a tripod (and switch to a D700) and secure it fully, plus stop it down a bit to f/7.1 at 500mm:
And the 100% view:
Better, but still not great. Note that small detail (hair, texture in antlers) is not crisp. This is what I'd call fair. The lens does better than this at 400mm. Noticeably better. Which is why I suggest you don't use it past that focal length.
Vignetting is evident in the corners at 500mm on FX bodies, at all apertures. It's not huge (less than a stop wide open), but it's clearly visible. At 150mm, vignetting is minimal wide open (very corners clip slightly) and essentially non-existent by f/11. The in-between focal length ranges are, not surprisingly, somewhere in between those two. Vignetting isn't really an issue on DX.
There's a visible amount of chromatic aberration, mostly on high contrast edges, but all things considered, I don't consider it to be a big problem. I was able to easily remove it in post. Linear distortion is low and excellent throughout the focal length range, and is always a very slight pin cushion (no more than about .2%).
Flare is handled reasonably well, but I detect strong contrast decreases with strong light sources in the shot and when not using the supplied lens hood.
Focus speed is not quite as good as you'd expect with HSM: it's a little slower than some of the shorter HSM zooms I've tried. But it seems to work accurately. The OS system is noisy and a bit slow to engage, which intersects with that focusing when you're trying to lock onto a fast moving target (e.g. birds in flight). Further, OS doesn't seem to stabilize the viewfinder the way you see in the Nikon VR system: there's a bit of jumpiness to Sigma's system. Also, note that in low light at 500mm f/6.3 you're probably beyond the capabilities of the Nikon body for fastest focus. In practice, I never saw the lens fail to focus, but I did see instances in lower light where the camera focused more slowly than it did in brighter light, which is an indicator of getting close to the point where not enough light is getting to the focus system.
This is a tricky review, because those who are strongly tempted to get this lens are coming at telephoto from a strong budgetary restriction, and often are also getting into their first truly long lens. There's good news and bad news here. First, let me state unequivocally that the 150-500mm at 500mm does not play in the realm of the Nikkor 500mm f/4. It's clearly softer, with less contrast, and has noticeably more chromatic aberration at 500mm. That, plus you'll be at f/8 to get its best results while the Nikkor 500mm f/4 is optically better two stops faster. You get what you pay for.
On the other hand, the 150-500mm is better at 400mm in most respects than the Nikkor 80-400mm. That should raise some eyebrows. On your other (third) hand, it's a bigger lens physically than the Nikkor 80-400mm, and that may mean something important to some people. Still, from about 200 to 400mm on this Sigma, I find it very usable, as long as you don't mind the dim viewfinder from the small apertures involved.
I should note that my assistant had the Sigma 120-400mm for awhile while we were testing the 150-500mm. It's no contest here: the 150-500mm beats the shorter lens in the entire range the shorter lens is capable of. I tried a second sample of the 120-400mm and found the same thing.
|Recommended (to 400mm)
||review source: purchased lens
||Nothing substantive missing; slow aperture dings it a bit
||A good 200-400mm lens, not so much outside that range
||Better than you expect for the price
Ratings last updated: 8/12/2011