Sigma 18-200mm f/3.5-6.3 DC OS HSM
Lab Test Results
April 19, 2010
by Andrew Alexander
Note: we originally reviewed this lens in May 2008, and it provided us with below-average results. As a result of user feedback, we have elected to re-test this lens.
The 18-200mm ƒ/3.5-6.3 OS is Sigma's second foray into the realm of optically-stabilized lenses, released in early 2007 following its announcement at Photokina 2006. Available for Sigma, Nikon and Canon camera bodies, the lens is a fairly ambitious design, with 18 elements in 13 groups, including 3 super-low dispersion and 2 aspherical elements.
The 18-200mm isn't a ''constant'' lens, in that as you increase the focal length, both the maximum and minimum aperture sizes decrease. The following table reflects the change in aperture with focal length:
|Focal Length (mm)||18-27||28-34||35-49||50-74||75-199||200|
The 18-200mm bears Sigma's DC specification, meaning it is designed to fit the APS-C digital sensor. The lens shows hard vignetting when affixed to a full-frame body, at all focal lengths. The lens is available now for around $370, takes 72mm filters, and comes with a petal-style lens hood.
Our original review in 2008 for this lens was quite critical, especially wide open at 35mm, where image sharpness was all over the place. The latest sample of the lens has improved somewhat, but is by no means perfect.
The sharpness of the 18-200mm f/3.5-6.3, when used wide open, is fairly decent when used at either its wide end (18mm) or full telephoto (200mm). At 18mm, there's a nice sweet spot of sharpness in the middle of the frame in the range of 1-1.5 blur units, softening slightly in the corners to a maximum of 3-4 blur units. As the lens is zoomed in however, image sharpness takes a hit, even as soon as 29mm, where we note a complicated and uneven pattern of blurring in the frame: on average, probably around 3 blur units. There's a tiny sweet spot of sharpness in the middle, but it quickly degrades to strong corner softness. This is very similar to what we saw in 2008. Things stabilize a bit by 36mm, where we get a more ''typical'' pattern of central sharpness and corner softness - in this case, a small sweet spot of 1.5 blur units, quickly softening to 6-10 blur units in the corners.
Zooming in further to 50mm (at f/4.8), things clean up quite quickly, and we're left with some image sharpness in the middle (~1.5 blur units), but slightly de-centered, showing slightly softer corners on the left but strong corner softness on the right (4-5 blur units). Zooming in further to 80mm, things go off the rails again, and we're back to a tight sweet spot of sharpness in the middle - around 1.5 blur units - degrading to very soft corners, around 9-10 blur units. Zooming in further, things settle down again at 135mm, with a generalized sharpness of around 1.5 blur units in the center and 4 blur units in the corners - leaning more to the 4 blur units side of things in this case. At 200mm, it's showing fairly good performance wide open at f/6.3, at 2-3 blur units across the frame.
Stopping down does improve image sharpness noticeably, especially at the ''trouble-spot'' focal lengths of 29mm, 36mm and 80mm. At the 29mm setting, images become quite sharp at f/8-11; for 36mm, it's f/11-16; and at the 80mm setting, it's also f/11-16. Fully stopped-down performance is good below 50mm (around 2 blur units), and average to poor above 50mm (3-5 blur units).
The verdict for this lens is an interesting one. At certain settings, this lens actually produces decent results, but you have to be very careful to know what these are. Fortunately, they include the most frequently-used focal lengths and apertures; wide-open, and either full wide-angle (18mm), the mid-range (50mm) or full telephoto (200mm). Anything else, and you're asking for some kind of softness issue, and not just in the corners. This is assuming you're using the lens at its widest aperture; by ƒ/11, this provision isn't as applicable, and the lens can be used normally to produce acceptably sharp images (though there are still traces of corner softness in the ''trouble'' focal lengths).
The 18-200mm shows some evidence of chromatic aberration, and here the Sigma is in line with other superzoom lenses; the chromatic aberration results are most noticeable at the extreme ends of the focal range (18mm and 200mm). At 18mm average CA performance is noticeable - 4/100ths of a percent of frame height - but it's the maximum value that concerns us most, at 9/100ths of a percent of frame height. Performance seems to be irrelevant to aperture, dependent mostly on focal length, though at the telephoto end we see slightly better performance with wider apertures than smaller. CA tolerance is best in the focal mid-range, at 35-50mm.
Corner shading isn't too much of an issue with the 18-200mm, with its worst performance showing up at 18mm. Used wide open (ƒ/3.5) you will see the corners are 2/3 of a stop darker than the center. At any other focal length, you will only see minor corner shading issues when used wide open; if you can set your aperture to ƒ/5.6-8, corner shading is reduced to less than a quarter-stop.
The 18-200mm produces a distortion profile which is fairly typical for this class of lens; barrel-distortion at the wide end (18mm), with increasing pincushion distortion as the lens is set to a larger focal length. Barrel distortion is fairly severe at the wide end: 0.8% maximum (corner) distortion at 18mm, with 0.5% overall. This distortion is fairly linear until about 25mm, where maximum distortion enters the pincushion style (''squeeze'').
After 25mm, average distortion retains its barrel character (between 0.2-0.3%), but maximum distortion is visible in the corners as pincushion distortion. At its most visible (35-50mm) there is -0.5% pincushion distortion.
Distortion will be difficult to correct simply in image post-processing, at least at focal lengths over 25mm, given the mix of barrel distortion in the central region of the image and pincushion distortion in the corners. Correcting for one will accentuate the distortion of the other.
The Sigma 18-200mm bears the HSM (hypersonic motor) designation, focusing very quickly and very silently on our Canon EOS-20D test body. However, most of Sigma's HSM lenses allow the user to override autofocus results by just turning the focus dial; the instruction manual with this lens advises not try to focus manually if the switch is in the AF mode.
Note: we used a Nikon F-mount sample for the 2010 re-test, but the operation was similar.
The 18-200mm isn't rated as a macro lens, as its 0.26x magnification results attest. However, its minimum close-focus distance is only 45cm (~18 inches), which after taking the actual lens and body length into consideration, means your subject can be as little as 7 inches away at 200mm, and 4.5 inches at 18mm.
Build Quality and Handling
The lens is solidly built, with a very tough finish. It isn't overly heavy (610g / 21.7 oz), balancing well on our test body. There is plenty to look at on the lens, with a distance scale etched into the focus ring, a magnification scale on the lens barrel, and focal lengths marked on the zoom ring. A manual focus override switch and optical stabilizer switch are mounted near the rear of the lens, and a ring-mounted switch allows the user to lock the lens at 18mm to prevent zoom creep.
The prominent zoom ring, taking up half the lens body, needs only a quarter-turn to go through its entire range of focal lengths. The ring is fairly stiff and resistant to zoom creep, but as mentioned, Sigma has preempted zoom creep issues with the inclusion of a zoom lock switch. The design of the lens is such that as the lens extends its focal length the barrel physically extends, adding a further 2 1/2'' to the overall length at 200mm (almost doubling the length of the lens).
The focus ring is much less prominent than the zoom ring, also taking much less than a quarter-turn to go through the lens' entire focus range. Unfortunately this lack of ''play'' makes it difficult to get a precision manual focus; this is slightly improved by the smoothness of the focus ring, which offers good tactile feel during manual focus operations. The front filter ring doesn't rotate during focus or zoom operations, making polarizer use quite easy.
The lens hood is petal-shaped with flat black ribbing inside. The hood measures 1 3/4'' long overall, and when attached adds about 1 1/2'' to the length of the lens. It reverses for storage and is included with the lens.
The main draw for this lens is its image stabilization feature. Sigma doesn't advertise how effective the system is in terms of ''additional stops'' of usage, a rare turn in advertising honesty as the effect is heavily reliant on the ''shakiness'' of the shooter employing the lens. In our limited testing the system works well. Image stabilization is activated with a half-press of the shutter button, and you hear a barely audible whirring as the system is active.
Sigma 18-200mm ƒ/3.5-6.3 DC ~$350
The similarity between the OS and non-OS versions is considerable. Optically the non-OS version is slightly sharper (at least, producing less ''funky'' results), but produces more chromatic aberration at the extreme ends. Corner shading and distortion results are about the same. For the extra money you get HSM and optical stabilization for only a slightly hit in optical performance.
Canon EF-S 18-200mm f/3.5-5.6 IS ~$600
For a while, Canon didn't offer a lens with this range of focal lengths, but they solved that with the release of this lens. Sharpness is considerably better with the Canon: CA performance, distortion and corner shading are all similar. Both lenses have some form of image stabilization: the Canon costs slightly more.
Tamron 18-250mm ƒ/3.5-6.3 Di II LD Aspherical IF Macro AF ~$450
Tamron produces a comparable 18-200mm, but its optical quality is generally poorer than the Sigma; Tamron's 18-250mm, however, is remarkably good, with excellent results for sharpness, chromatic aberration and corner shading (distortion remains typical for a superzoom).
Tamron 28-300mm ƒ/3.5-6.3 XR Di VC LD Aspherical IF Macro AF ~$575
Tamron's latest superzoom incorporates their own image stabilization system (vibration compensation, VC). We haven't yet tested it, but it's also worth noting it's a full-frame lens. Available for Nikon and Canon lens mounts.
Nikon 18-200mm ƒ/3.5-5.6G IF-ED AF-S DX VR Nikkor ~$700
Optically, the Nikon is marginally better than Sigma's 18-200mm: somewhat sharper, similar with regard to CA, a bit worse for corner shading, and similar distortion. The Nikkor also exhibits a bit of the ''off-kilter'' nature shown by the Sigma: good at 18mm, 50mm and 200mm, but slight corner softness issues outside of these ranges.
It's hard to overlook the obvious problems with sharpness but what I find most fascinating is how isolated they are. If you were fine living without 28, 35 and 80mm, somehow magically avoiding them when framing images by zoom, I'd say you get above-average performance out of this lens. Image stabilization is a welcome function, especially given the aperture limitations of the lens; its maximum aperture of ƒ/3.5 disappears quite quickly as the focal length increases.
As always, lens design, especially with these superzoom-style lenses, is about managing your sacrifices; a better lens would cost more, or weigh more, or both. Nikon and Canon shooters are better served by their respective brand-name 18-200mm lenses, for a few dollars more. If it's too much to pay, the Sigma is an acceptable choice, so long as you're prepared to commit a few details to memory concerning the settings not to use.
The VFA target should give you a good idea of sharpness in the center and corners, as well as some idea of the extent of barrel or pincushion distortion and chromatic aberration, while the Still Life subject may help in judging contrast and color. We shoot both images using the default JPEG settings and manual white balance of our test bodies, so the images should be quite consistent from lens to lens.
As appropriate, we shoot these with both full-frame and sub-frame bodies, at a range of focal lengths, and at both maximum aperture and ƒ/8. For the ''VFA'' target (the viewfinder accuracy target from Imaging Resource), we also provide sample crops from the center and upper-left corner of each shot, so you can quickly get a sense of relative sharpness, without having to download and inspect the full-res images. To avoid space limitations with the layout of our review pages, indexes to the test shots launch in separate windows.
Sigma 18-200mm f/3.5-6.3 DC OS HSM
Sigma 18-200mm f/3.5-6.3 DC OS HSM User Reviews
8 out of 10 points and recommended by mannypr (3 reviews)Built , overall good sharpness , effective OSInconsistence in sharpness , prone to veiling flare , heavy
This is a nice lens . It's very sharp from 18mm-75mm with very low distortion. From 75 it is a bit soft at the corners but still sharp in center . at about 100mm it's soft again getting sharp by 135mm and at 200mm it's quite good for an inexpensive lens. It's built is remarkable for a lens at this price. OS system is very effective giving me about 2 or 3 stops .Colors are a bit warmish but that is very subjective in nature. This lens in some quarters have recieved a bad rap but I believe it's because of faulty quality control . Those that come out good are much more then good. I recommend this lens given the caveat that you buy from a reputable dealer that's willing to exchange the lens for another one . It's a very good walk around lens.reviewed November 6th, 2010 (purchased for $375)
10 out of 10 points and recommended by koolou (1 reviews)Very reasonable costNone
I have never had a Sigma lens before for any of my previous DSLR's but decided to purchase this Sigma 18-200 for it's large zoom (11.1X) and also its large filter size(72mm)reviewed May 6th, 2010 (purchased for $369)
Having optical stabilization was another factor in my buying this lens.
I have been very satisfied in the pictures I took with this lens which have been mostly landscape that have shown very sharp detail.
8 out of 10 points and recommended by steve_h (1 reviews)OS, wide range zoom, low cost, small size, good buildCorner softness
I had a non OS Sigma 18-200 and it was a nice little walk around lens. Took very nice shots with my Canon XTi. I upgraded to the OS version to get the OS function. It seems to work well – probably provides me with 2-3 stops performance and saves a lot of shots for me in less than bright light. Focus is fast / accurate and the operation is quiet.reviewed May 27th, 2008 (purchased for $450)
I did notice that in all focal lengths the center sharpness and contrast was better than my non OS version (I did many comparison shots on a tripod), but that at many focal lengths the corners have more blur than the non OS version (Upper right being the worst by far and lower left being slightly worse than the other corners).
Since most of my shots are landscape in nature with a stronger ‘central interest point’ it really doesn’t show up too much in real life looking at prints – only when pixel peeping can it be seen (for instance in tree leaves at the edges of the frame).
I rarely work wide open except when I want minimum Depth of Field and usually work at f8 to f11.
The lens is quite sharp and does a good job with larger flowers in close up work – it has acceptably good close focus range for a walk around lens.
All in all I like the lens and find that its reach is very good – about 29 to 320 mm / 35 mm equiv on my Canon XTi. If it needs to be super sharp anywhere it’s at the long end and the lens performs well there.
If the corners were sharper then I would have rated the image quality higher since the center is very good.
I would buy it again.
10 out of 10 points and recommended by spuelijah (9 reviews)nice finish & build, 72mm threadauto-focus hunts in low light & makes a buzz sound, f/6.3
This is my fourth Sigma lens. I also own a 30mm f/1.4 and the 10-20mm, but I sold a 150mm f/2.8 macro. I've had three Nikons as well, but they've all been sold.reviewed May 7th, 2008 (purchased for $450)
Although this one is not an EX lens like the others, the quality is nearly as good. Some people don't like the matte, speckle finish of Sigma lenses, but I prefer it.
For the price this lens is hard to be beat. Last I checked online pricing, it was $250 less than the Nikon 18-200mm VR and $100 less than the new Tamron 28-300mm VC. Sharpness is very good and better than the Nikon as reviewed by pophoto.com.
Luckily Sigma incorporates their HSM technology for the Nikon versions, but sadly it isn't nearly as good as Nikon's SWM techology. Focus had to hunt in low light, and it made an annoying buzzing sound when the auto-focus was engaging. But the results are worth it. I can shoot still objects indoors as low as 1/5 of a second and get sharp photos.
10 out of 10 points and recommended by trentdp (26 reviews)Excellent vacation lensNone I can personally attest to
I use this lens on my Canon 40D in the same way I use the Nikon 18-200VR on my Nikon D200. It is a great all in one lens when you only want to have one lens on your camera for your outing.reviewed January 12th, 2008 (purchased for $429)
It is suggested that any interested potential purchaser of this lens navigate to the following link for a very good and accurate assessment of this lens. I based my purchase on this assessment and do not regret my decision at all.
This is a very good lens for it's intended use. It is not excellent in any given category but when you evaluate the entire package, it has no peers in the Canon stable or from other 3rd party providers.
There may have been some early release problems, but for the most part I believe Sigma has stepped up to the bar and corrected the initial problems with this lens.
I highly recommend it to someone who wants a great "vacation lens" for use on canon products.
10 out of 10 points and recommended by orion (1 reviews)Great OS, pretty fast auto-focus, 98% accurate, good sharpness overall.Softness near edges at wide apertures.
I originally had the non-OS version and did not intend to buy the OS version assuming that the overall quality would be about the same except for the OS, which I thought I could live without.reviewed December 22nd, 2007 (purchased for $510)
However, when I saw the first samples posted by a user, I was near convinced and after I bought the lens and tried it out for a couple of days, I knew I had not made a mistake.
What struck from the samples were the superb performance of the OS and the fantastic zoom range with two shots he took (while in a moving bus) from 18mm to 200mm close-up with both very sharp.
Most of my photography is done on the move, indoors and outdoors, at close quarters and then zooming out to capture something in the distance. With the OS, let's say, of 100 blurred shots caused by hand shake, this number has now been reduced to 10 or even less.
My use of flash has dropped too and now instead of 800 or 1600 ISO, I can get good, sharp shots at 400 ISO indoors using natural lighting. I have been successful as low as 1/4 second at 200mm though the success rate is somewhere around 30% to 40%.
In the 5 months that I have used the Sigma, I have never had any problems with colour rendition from this lens and most times, they are clear and vibrant, particularly if I take off the UV filter and just rely on the lens hood for added protection.
I have never used any L lenses and my experience is limited to the original kit lens, the Sigma 28-200, 18-200 and then the Canon 50mm f1.8 II. The Sigma 18-200 OS outperforms the first three of these for focusing speed, accuracy, image quality and, of course, low shutter-speed photography with its excellent OS. It matches the Canon 50mm f1.8 II near the center but, of course, not near the edges or for distortion. It's focus is quieter than the Canon 50mm f1.8, faster and more accurate. I have had many more out-of-focus shots with the Canon 50mm than the Sigma.
I have tested 5 copies of this lens with one that seemed a tiny bit worse OS-wise but I wasn't absolutely sure as time was limited. I bought two - one for myself and one for my nephew living in Canada. He regularly updates me on the shots he has taken and posts in his online album. He's very happy with it and calls it his "trusty Sigma". A friend of his is so impressed with the lens, he will be buying one this Christmas on his holiday trip over here.
Having read a previous post here, I tried out DXO Optics Pro on my Sigma shots. There is some improvement but not to the point where the original shots would be considered not good or unacceptable. The most obvious improvements so far (as I have only used DXO for about a week) are the reduction of CA, distortion and exposure adjustment between light and shadow. For CA, you would have to inspect the edges of the shot at 100% to really see the difference. I cannot see any difference in colour as yet. Perhaps, I need to explore further. However, DXO is definitely a good piece of software to use with this lens and I will continue to use it.
If one isn't into professional photography but wants convenience, good overall image quality, lots of keepers from shooting in different lighting conditions, particularly on travel (as it has done for me), this is a good lens to have on the camera.
2 out of 10 points and not recommended by zoomfreak (9 reviews)build quality (that is good)horrible color , horribe resolution , pronounced CA, pronounced distortion
bought this to try to replace my travel lens the EF-S17-85IS , but this is a horrible lens.reviewed December 8th, 2007 (purchased for $450)
I kept my Canon Ef-S17-85IS as my travel and day light lens.
I have EF-S17-55f2.8IS for my work and serious shooting so this lens has no place in my kit.
8 out of 10 points and recommended by touristguy87 (33 reviews)zoom range, price, weight, size all goodnot an "L" lens :) I'd recommend this lens MAYBE depending on what you want it for
Ok this is attempt #6 to write a review of this lens. Maybe shorter=better.reviewed August 22nd, 2007 (purchased for $560)
First, I have to say that I have gotten a lot of good shots from this lens on a 400d and a 30d, at F8, using DxO. Even at F6.3 shooting 200mm handheld at night, it has surprised me.
Second, I have to say that it has blown what *would* have been a lot of good shots for me, due to bad focus. It is decent in bright daylight, or at night when there are plenty of lights for it to focus on. It needs *bright* subjects (note that this does not equal "brightly-lit subjects"). It shoots ok in high-contrast scenes. If it is overcast or hazy in the evening then it will drive you nuts with focus-misses. But this problem is also partially the 400d, so don't be surprised if you see this with a 400d even if you don't get this lens. If you look at your shots closely.
Still, if you get this lens, be prepared to go through the whole gamut of emotions, from pleasure to laughter to anger to frustration to tears. I would try the new Tamron 18-270VC first. I've shot the 18-250 and the 28-300VC and one very noticeable difference between them and the Nikon and Sigma equivalents is that there is no need to use a lens-correction module to get sharp shots out of them. I expect the same with the new 18-270VC. Also I would just sell the Rebel and get at least the 30D, yes the 30D is much bigger and you will lose a little resolution but you gain a very-usable ISO3200 and the AF system is FAAAARRRRR better (plus you get a real LED display and the battery life is much better too). The 30D makes the 400D look like an overgrown p&s. I shot the Sigma 18-200 DC OS on a 30D and it was almost a different lens, only reason I sold it was to get a D300 and ISO6400 but the Tamron superzooms are really the answer. Besides you can only do so much with ISO6400 on a subframe.
So probably this lens is ok at F8 with some software-correction but it's still short now and I'd have to get it at a real discount. It truly sucks near wide-open, but sharpens-up abruptly at F8, another way in which the Tamrons beat it. But, if you don't need over 300mm effective and you want a cheap, light lens that you won't cry over if it gets scratched or breaks, if you don't mind the noise of the focus-motor...it will take some decent pics at F8 if it gets a good focus. It's not a piece of crap. I wouldn't *avoid* it like I'd avoid the Nikon 18-200VR2.
3 out of 10 points and not recommended by EF-S10-22 (19 reviews)range, OS.Horrible color rendition, soft coner throughout the range, AF problems
I sold it , it is slow(AF speed) and heavy .reviewed July 31st, 2007 (purchased for $450)
I think I was one of these first people to order this and have had it lonest since I was in OSaka when I bought it .
I got it on June 1.
Initially linked it , excited about it like the previous guy.
But as I heard so many AF issues and saw people returning it to Siagm in Japan , I realized that there would be something serious there.
The AF issue being so famous among Japanese mags is a very weird problem:
once you use it in MF mode for more than 10 munites , it won't AF until you turn your camera off for a while(my case was longer than 10munites of turing off to re-activate the AF function).
This issue is talked about all the time on line in Japan, and the wide angle AF issue is also described clearly in a Local mag in my city .
These problems happened to me about a week a go and I decided to return it to fund for an EF100 macro.
I think it is an ok lens if you do not have the AF-MF issue , but many people already documenting it clearly and it is so soft lens , especially from 35-105 range , and this issue was discussed at photozone.de forum.
I post the link here.
I do think this lens has a serious design problem.
So make sure to read the photozone.de forum first before making any decision.
10 out of 10 points and recommended by katzer (4 reviews)Range, Superb OS, Sharp stopped down, Contrast & Color, Canon mountSlow lens, Sharpness wide open could be better
There are macro lenses for macro photographyreviewed July 30th, 2007 (purchased for $630)
There are ultra wide lenses for landscape photography.
There a portrait lenses. There are fisheye lenses.
Each lens has a specific usage.
This lens is intended for times when you can take only one lens. If you can take 2 lenses and don't mind the weight/switching lenses - go for it.
Most of the times when I am out on a taking pictures trip, I take a bag full of lenses.
I can't do it always. In cases when I have to go lite - this lens fits the bill.
There are compromises: It is a slow lens that benefits from stopping it down a bit. Once it is down 1-2 stops - picture quality is great. Picture is still pretty sharp in the center wide open.
The most impressive feature is the OS.
I get consistently sharp images at 200mm at 1/20sec (!). I have a high keeper rate at even slower shutter speeds. Couple that with extremely useful range, and you get a lens you can literally weld to your camera on vacations.
The only other option for canon mount is the 28-300L which costs four times the price of this one, and to actually get the same range you'd need to get a full frame camera. Since this lens has to compete with the Nikon 18-200VR, the price is actually pretty darn good.
I like this lens a lot. It is a very practical tool which is a joy to use and quite rewarding when reviewing the results. You just need to use it for what it is intended for.
I created a gallery for this lens, in time I will add more pictures: