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Pictured here with a couple of it's considerably more expensive alternatives the Sigma 150-500mm OS lens is a small compact and very light weight unit.
Before we get down to what I think let's see what Sigma have to say:
"This ultra-telephoto zoom lens covers a telephoto range up to 500mm and allows photographers to bring the subject close with short perspective. Sigma’s original OS (Optical Stabilizer) function offers the equivalent of using a shutter speed approximately 4 stops faster. It is ideal for sports, wildlife and landscape photography with handheld shooting.
Three SLD (Special Low Dispersion) glass elements provide excellent correction for chromatic aberration. This lens is equipped with a rear focus system that minimizes fluctuation of aberration caused by focusing. The super multi-layer lens coating reduces flare and ghosting. High image quality is assured throughout the entire zoom range.
This lens incorporates HSM (Hyper Sonic Motor), which ensures a quiet and high-speed AF as well as full-time manual focusing capability.
The addition of the (optional) 1.4x EX DG APO or 2x EX DG APO Tele Converters produce a 210-700mm F7-8.8 MF ultra-telephoto zoom lens or a 300-1000mm F10-12.6 MF ultra-telephoto zoom lens respectively. A removable tripod collar (TS-31) is included as a standard component."
Mmmm....well!
Okay, here's the specifications of the lens:
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Lens Construction |
21 Elements in 15 Groups |
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Angle of View |
16.4 - 5 degrees |
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Number of Diaphragm Blades |
9 Blades |
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Minimum Aperture |
F22 |
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Minimum Focusing Distance |
220cm |
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Maximum Magnification |
1:5.2 |
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Filter Size |
86mm |
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Dimensions |
Diameter 94.7mm X Length 252mm |
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Weight |
1,910g |
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SRP |
£749.99 |
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So what do you get for your hard-earned?
Opening the box you are greeted with the ubiquitous Sigma black padded case and the usual bits of paperwork.
The lens comes with an 86mm lens cap and a fairly robust if somewhat too short lens hood - this is a 500mm remember Sigma!
If you like lenses to have a lot of switches on them (which I don't) and you've been lusting after this lens 'cos you like the three switches you can see in the image above the specs, then you will feel robbed - at least if you have the Nikon mount version. Lord only knows what the switch on top of the lens in the picture does, but it's immaterial 'cos it ain't there on this version.
The lens body is finished with the usual Sigma dull matt black paint job.
Working from the front of the lens the next item we come to is the zoom ring, which is marked off in 150, 200, 250, 300, 400 and 500mm focal lengths.
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Next we come to the control switches, the first of which is the zoom ring lock, which is engaged when the lens ships, so you need to flick it to the UNLOCK position before you try and rotate the zoom ring.
Next comes the manual focus ring, slightly narrower than the zoom ring and quite nice and smooth in operation.
Then comes the rear bank of switches. The top switch activates or disables auto focus, and the lower one is the switch to control the OS or Optical Stabilization system.
There are 3 positions, OFF, Mode 1 and Mode 2.
Lastly we come to the rotating lens collar.
Please note that there is no aperture ring on this lens so it can only be used on camera bodies with internal electronic aperture control.
Okay, let's do this review then.
Build and overall appearance
There's quite a bit of plastic used in the construction of this lens but it does feel quite robust, though how it effects the lens in extremes of temperature is anyones' guess.
The overall appearance of the lens is fine, there's no reflective surfaces, the rubberized grips on the zoom and focus rings are effective even for wet fingers, and all the external lens markings are clear and well delineated. They are however just transferred on - there is no engraving, so whether the marks will ever rub off or not is a matter of conjecture.
The AF/OS switch block does protrude from the lens side quite a bit and could be prone to the odd knock, so care needs to be taken when moving around on rocks for instance, or getting in and out of a car with the lens 'ready for action'.
Operation
I must admit that quite often my feelings about lenses like this are, shall we say somewhat circumspect, and to be brutally honest, when I got it out of the box those waves of derision swept over me in such a flood that Noah nearly ran to the garden shed for his chainsaw again.
Why?
Well, for a start the ZOOM and FOCUS rings are the wrong way round, zoom should be at the back and focus at the front, that way your 'lens' hand is where it needs to be, balancing the whole 'shebang' and always ready to either manually focus or make manual adjustments to override the AF in single servo mode.
When I disengaged the zoom lock I was expecting the zoom ring to operate in the same silky smooth manner as did the misplaced focusing ring - instead, I felt a distinct urge to call Jeff Capes for assistance - stiff does not even begin to describe it!
With the camera at your eye this stiffness in the zoom ring makes it very hard work to actually change focal length if you are trying to compose a nice shot - you create that much camera movement doing so that you can loose sight of the subject.
Mounting the lens on a D300 body and flicking the AF switch ON I was very pleased with the lack of noise from the HSM focus motor and I was also quite impressed with the focus speed. It won't set any records in that department but I do think it's somewhat quicker than some, including the Sigma 50-500mm.
Optical Stabilization/OS
Now there are two positions for active OS on the lens switch, position 1 compensates for movement along both the horizontal and vertical axes, and position 2 along the vertical axis only which allows for panning the camera.
It's important to remember that the OS is a bit 'primitive' by today's standards and doesn't cater for tripod mounting the lens so the OS needs to be turned OFF if you are going to use the lens on a tripod.
So, setting the AF to position 1 and choosing a static subject, when I hit the first pressure on the shutter button I thought someone had turned on a food blender!
Oh brother it it noisy!
And slow! Unlike the system in my 200-400VR Nikon, which gives you the impression it's always awake and ready to go - even when it's in its case with no body attached, rather like some acid-tripping terrier - the Sigma OS in this lens is more like a slovenly youth who needs to be poked in the back with a javelin in order to wake him up.
But once the OS has gathered its whit's and worked out what day it is then it does its job admirably.
The only problem is, whilst the OS is whirring away like a Magimix it consuming power from your camera battery by the Gigawatt - spare batteries - don't leave home without a few - you've been warned!
Handling & Performance
Before we actually get on to picture taking, a word about the aperture. The lens is NOT a constant aperture throughout its focal length range, that's something that costs a lot of money to obtain.
As you go move through the zoom range of this lens the aperture changes as follows:
| 150mm | f5 |
| 165mm | f5.3 |
| 205mm | f5.6 |
| 280mm | f6 |
| 355mm | f6.3 |
Not that it makes too much difference, but you need to be aware of it in order to understand why you may get 'Lo' warnings in shutter priority exposure mode if you change to a longer focal length.
So, what are the pictures like - after all, this is what we all want to know!
Well, leaning against a tree and shooting hand-held with the OS in position 1 (all directions) and shooting at 1/150th@ f8 (150mm) down to 1/60th@f8 (500mm) I was surprised how quickly the lens acquired focus.
On viewing the results below I found what I expected - the sharpest images are in the middle of the zoom range ie: 200/300/400mm.
Full frame |
Native (100% crop from sensor) |
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150mm 1/150th |
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200mm 1/125th |
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250mm 1/100th |
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300mm 1/80th |
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400mm 1/80th |
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500mm 1/60th |
And YES my car needs a clean!
But shots of static subjects in good light are not the way to test a lens.
What everyone is interested in is tracking moving subjects and taking images in average light, so what better way to test it than at 1600iso in heavy overcast photographing something moving at 70mph!
The images below are all from the full frames.
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Now the image above was a real tester - typically the test you give wide-angle lenses to test for chromatic aberration. You'll notice that I've dropped the shutter speed by 2/3 of a stop thus over-exposing the white sky in order to turn the frame contrast up. Any dark fine detail that is against the over exposed sky will now show colour fringing if the lens has chromatic aberration faults |
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As you can see there is distinct cyan and green fringing to this image, but to be honest it's nowhere near as bad as I've seen in a lot of lenses and is, for the most part, fairly easily manageable in in a quality RAW editor. As for sharpness, when you consider the iso 'noise' in the image and the fact that this lens is sharper at around f8 than wide-open, I for one am fairly impressed. Yes, if I'd shot this image with my 200-400VR or a 500 f4VR then I would most likely have a much sharper image AND it would be chroma error free. But either of those lenses will cost at least 6 to 8 times more than this offering from Sigma, and shooting in these conditions would show flaws in lenses costing considerably more the £700! In Conclusion. Overall the lens has left me with the impression that it is what it is - a budget lens that does the job it was intended for. Would I use one for my own work - certainly NOT - I couldn't afford to. Would I call you mad for buying one - if you could afford a bigger budget the yes I would. But if you are looking for a 'first departure' from the standard lens your DSLR came with, and you are on a tight budget but want to learn as you move on then, as a stepping stone to bigger and more expensive glass then there's nothing wrong with it. It will help beginners learn some of the pitfalls of long-lens work and it will certainly help them learn about the intricacies of their cameras AF system.
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