Sony E 18-200mm f/3.5-6.3 OSS SEL18200

SLRgear Review
June 14, 2011
by Andrew Alexander

Released alongside the Sony NEX5 mirrorless digital camera, the 18-200mm is an all-in-one superzoom lens that offers an effective range of 27-300mm. It's almost comical to look at the camera-lens combination when they're attached - the lens is easily three times the size of the camera.

The lens was designed specifically for the NEX series of cameras, and won't work on other Sony alpha bodies. The lens uses a variable aperture, 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:

The lens takes 67mm filters, and ships with the ALC-SH109 petal-shaped hood. The lens is available now for around $800.

Sharpness
The Sony 18-200mm ƒ/3.5-6.3E offers very good results for sharpness, and unlike some superzooms, doesn't drop off quickly in the telephoto range.

Used at its widest angle (18mm), the lens produces sharp images, even when used at its widest aperture (ƒ/3.5). In fact, its best performance is found when used wide open (ƒ/3.5-ƒ/4) - stopping down doesn't offer any improvement for sharpness. Diffraction limiting sets in at ƒ/8-ƒ/11, but there's no noticeable sharpness drop-off until ƒ/16.

In the zoom mid-range (35-70mm) the lens also produces sharp images, even wide open, although in this case you get a tad more sharpness when you stop down to ƒ/8-11. In the telephoto range (100-200mm) we notice a slight aberration in performance at the 100mm setting and wide open at ƒ/5.6 - there are some soft corners there. Sony may be pushing the envelope with the lens design here; the company could be commended for keeping the variable aperture at ƒ/5.6 for as long as it can, including 100mm, but the side effect is that the corner performance isn't quite as good as in other focal lengths. Stop it down to ƒ/8, and it's as consistently good as other settings. Otherwise, telephoto performance is very good for sharpness, even at 200mm, which is decently sharp. It's not quite as good as other focal length settings, but this isn't very surprising given it's a superzoom, and perhaps the surprising part is that it's as good as it is. Many superzooms feel like the telephoto setting has been ''tacked on'' - not so here.

As is also usual in lenses in the category, fully stopped-down performance is nothing to write home about. It's not bad at wider focal lengths (18-35mm) - but at 50mm and higher, it gets quite soft indeed, and anything above ƒ/32 is best avoided.

Chromatic Aberration
Performance regarding CA is fairly good with this lens, with fringing only really visible at the wide (18mm) and extreme telephoto (200mm) focal lengths. Otherwise, there's no particular advantage in selecting one aperture over another.

Shading (''Vignetting'')
The smaller size of the APS-C sensor really helps the 18-200mm ƒ/3.5-6.3E avoid any significant corner shading. The only time it's really noteworthy is wide open at the widest setting (ƒ/3.5 at 18mm), where we note extreme corners which are 1/3EV darker than the center. Otherwise, the results aren't really a problem.

Distortion
Predictably, the complex array of lens elements that allows such a vast range of focal lengths in one lens leads to some dramatic results for distortion. When used in the wide angle configuration, the lens provides uniform barrel (''bloat'') distortion up to around 18mm, with dramatic distortion in the corners (1.25%, quite significant). After around 28mm, distortion across the frame remains consistently barrel-distorted, but at a moderately low level (around 0.25%, on average) and the extreme corner distortion turns into the pincushion (''squeeze'') style. The worst pincushion distortion is noted between 35-100mm, where the corners show -0.6% pincushion distortion. Post-processing would be required to correct for these effects.

Autofocus Operation
The Sony 18-200mm ƒ/3.5-6.3 E is fairly quick to autofocus - the lens takes just under a second to slew through the entire range of focus. Small changes in focus are conducted extremely quickly. The ring will turn all the way around with no stops. When using manual focus as you turn the ring the central section of the LCD displays an enlarged (7X or 14X) view of the image. It makes the camera very easy to use for manual focusing with this lens.

It's also worth noting that the focusing noise for this lens is very quiet, making it very useful for shooting movies.

Macro
Macro performance is above average, with a 0.35x magnification rating and a minimum close-focusing distance of 30 cm (just under 12 inches).

Build Quality and Handling
The Sony 18-200mm ƒ/3.5-6.3 E-mount lens is what you would expect a lens of this capability to look like, but when mounted to the NEX-3 or NEX-5 bodies it monstrously huge by comparison. While the lens itself isn't that heavy (524g / 18.5 oz), the small size of the NEX bodies means you'll be using this combination by primarily holding the lens.

The construction of the lens is very nice - metal focus and zoom rings with a metal shell, combined with a metal lens mount and a plastic filter ring. Seven rounded diaphragm elements make up the aperture, producing nice out-of-focus backgrounds. There only control surface on the lens other than the focus rings is a zoom lock switch, as all lens functions are controlled via the camera. As well, there is no distance scale, depth-of-field scale or infrared index marker.

The focusing ring is rubber with large ribs, about 1/2'' wide. The ring will rotate forever in either direction with no hard or soft stops, and doing so brings the camera into manual focusing mode, with the 7X or 14X enlargement as previously described. The placement of the ring may require some adjustment for conventional camera users - it's mounted behind the zoom ring, instead of at the end of the lens.

The zoom ring is almost one inch wide, rubber with large raised ribs. The ring is smooth to turn, though perhaps a little stiffer than we'd like, and offers 90 degrees of turning action to run through the available range of focal lengths. There is some significant lens extension as the lens is zoomed in towards 200mm: the lens adds 3'' to its overall length, almost doubling in size. Zoom creep is not a factor with this lens, but Sony has thought to include a zoom locking switch that keeps the lens fixed to the 18mm position.

The lens offers image stabilization, for which the results of our testing should be available soon. As well, autofocus is very quiet, making it quiet useful in movie mode.

The lens hood is a petal-shaped, bayonet-mounted design that is 2 inches long. The hood will reverse for storage on the lens. Another interesting accessory available for the lens is the FA-EX1S flash extender. This accessory fits between the flash and the hot shoe, and is used allow the flash to shoot with this lens without casting its shadow on your picture.

Alternatives

Unfortunately, with the newness of the NEX system, there isn't a lot of obvious choice. Sigma has pledged support for the E-mount, but as of the time of writing, no lenses are yet available. However, there's a whole industry in third-party lens adapters which make dozens of other manufacturer's lenses operable on Sony E-mount cameras.

Sony E 18-55mm ƒ/3.5-5.6 OSS ~$300
The kit lens that comes with the NEX camera package is fair lens in its own right, but it just isn't quite as good as the 18-200mm: the superzoom is sharper, CA isn't as prominent, distortion is less objectionable, and there's even slightly less corner shading.

Sony 18-200mm ƒ/3.5-6.3 DT ~$500
By means of the LA-EA1 mount adapter, one can attach standard alpha mount lenses onto the NEX body; in this case however, the older Sony 18-200mm isn't quite as good as the newer E-mount version: the only thing that's comparable is distortion, otherwise in all other categories, the E-mount lens is better.

Conclusion
Unless you've already got an alpha system lens you want to make use of with an adapter, the Sony 18-200mm ƒ/3.5-6.3 E is a no-brainer of an upgrade. Offering better performance than the kit lens, with more reach to boot, it's an obvious choice, so long as you don't mind carrying around a system that's more lens than camera.

Product Photos

Sample Photos

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.

Still Life shot

VFA target

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.