Canon EF-S 18-200mm 1:3.5-5.6 IS

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Canon EF-S 18-200mm 1:3.5-5.6 IS Empty Canon EF-S 18-200mm 1:3.5-5.6 IS

Δημοσίευση από  Την / Το Τετ Ιαν 14, 2009 9:32 pm

Canon EF-S 18-200mm 1:3.5-5.6 IS Frontpage

Canon EF-S 18-200mm 1:3.5-5.6 IS specifications
Street price • $699 (US)
• £550 (UK)

Date introduced August 2008
Maximum format size APS-C
Focal length 18-200mm
35mm equivalent focal length
(APS-C) 29-320mm
Diagonal Angle of view (APS-C) 74º - 8º

Maximum aperture F3.5-5.6
Minimum aperture F22-36
Lens Construction • 16 elements/12 groups
• 2 UD elements
• 2 Aspherical elements

Number of diaphragm blades 6, rounded

Minimum focus 0.45m/1.5ft
Maximum magnification 0.24x at 200mm

AF motor type Micro motor
Focus method Internal
Image stabilization • 4 stops
• Automatic panning detection

Filter thread • 72mm
• Does not rotate on focus
Supplied accessories • Front and rear caps

Optional accessories • EW-78D Hood
• Case

Weight 600 g (21.2 oz)
Dimensions 79 mm diameter x 102 mm length
(3.1 x 4.0 in)
Lens Mount Canon EF-S only
Other Supplies distance information for E-TTL II flash metering

Η Canon ανακοίνωσε τον EF-S 18-200mm f/3.5-5.6 IS για μηχανές crop 1.6x, ακούγοντας τις επιθυμίες των ερασιτεχνών, κυρίως, πελατών της που ζητούσαν ένα all around φακό για όλες τις χρήσεις που δεν υπήρχε στη γκάμα της εταιρείας. O φακός ανακοινώθηκε μαζί με τη κυκλοφορία της νέας Canon EOS 50D. Έχει οπτικό μήκος ισοδύναμο των 29-320 χιλ, προσφέρει 11x zoom, αποτελείται από 16 στοιχεία σε 12 γκρουπ, έχει UD και 4-stop Σταθεροποιητή εικόνας. Η έλλειψη USM, Full Time Manual Focus και η φτηνή ελαφριά πλαστική κατασκευή, ίσως είναι τα μειονεκτήματα του. Η διάμετρος του είναι 72 χιλ., ζυγίζει 600 γρ. και το μήκος του 102 χιλ.Η τιμή του κοντά στα 600€ στην Ελληνική αγορά.

To έγκριτο dpreview γράφει:

The EF-S 18-200mm F3.5-5.6 IS is Canon's latest zoom lens for APS-C format DSLRs, introduced as a companion to the EOS 50D. Its announcement in August this year came as no great surprise, as wide focal length range 'superzooms' are clearly popular amongst photographers seeking an all-in-one lens for travel and everyday shooting. The most obvious example of this is the runaway success of Nikon's AF-S 18-200mm F3.5-5.6G VR, and a Canon equivalent has almost certainly been the most-requested lens on our forums.

With its 11x zoom range, the 18-200mm becomes Canon's most ambitious consumer-level zoom to date; the company has previously shied away from producing relatively inexpensive superzooms, with its only previous foray into this sector being the 28-200mm F3.5-5.6 (USM) for 35mm SLRs from late 2000. And while it's this older lens that the 18-200mm most strongly resembles, Canon has managed to squeeze plenty more into the design in the intervening eight years. The zoom ratio has been stretched to a 35mm-equivalent range of 29-320mm, and the new lens incorporates Canon's latest compact image stabilization unit (as seen on the EF-S 18-55mm F3.5-5.6 IS and the EF-S 55-250mm F4.5-5.6 IS), which offers automatic panning detection and (according to the company) four stops of stabilization. All this has been achieved using a suitably complex optical design of 16 elements in 12 groups, including two UD glass elements and two aspherical elements which are designed to minimize chromatic aberration and ensure crisp corner-to-corner detail across the zoom range. Rounding off the specification is a minimum focus distance of 45cm/1.5ft at all focal lengths.

One design decision may however cause a degree of dismay; the lens uses a relatively unsophisticated micro motor system for autofocus, as opposed to the ring-type USM design more commonly seen on mid-range lenses such as the EF-S 17-85mm F3.5-5.6 IS USM. Consequently, potential buyers may struggle to find any obvious advantage over Tamron's recently announced 18-270mm F3.5-6.3Di II VC LD Aspherical (IF) Macro, which sports a longer zoom range and Tamron's own optical stabilization system. Aside from this, Canon have produced a lens which is clearly designed to counter the undeniable buyer appeal of Nikon's popular 18-200mm VR head-on; so how does it match up to the challenge?

Headline features
29-320mm equivalent focal length range; F3.5-5.6 maximum aperture
Optical image stabilization – 4 stops, automatic panning detection
EF-S mount for Canon APS-C DSLRS only

The 18-200mm performs much as we would expect from a superzoom; it's not outstanding, but should be quite usable within its limitations. In almost stereotypical Canon fashion, a weak performance at wideangle is balanced by a rather more convincing showing at telephoto; when compared to the Nikon AF-S 18-200mm F3.5-5.6 VR, the overall result therefore has to be declared as a score draw. Against either the EF-S 17-85mm F3.5-5.6 IS USM or EF-S 18-55mm F3.5-5.6 IS USM, the 18-200mm again looks poor at wideangle but better at longer focal lengths.
Resolution At 18mm F3.5 sharpness is high in the centre but drops progressively towards the corners, however cross-frame performance improves markedly by F5.6. At longer focal lengths, this pattern of decent central sharpness but soft corners wide open continues; generally though the central sharp region generally covers a larger area of the frame. Overall results improve through to around 50mm, then dip towards the mid-tele range with the weakest focal length being 135mm, before rallying again to a respectable showing at 200mm. Generally, best results are obtained a stop or two down from wide open. However, at no point does the lens really look like it's fully able to satisfy the demands of the 50D's 15 Mp sensor.

Chromatic Aberration Not this lens's strongest suit, chromatic aberration is very high at wideangle with strong red/cyan fringing. In the middle of the zoom range (~50mm) CA becomes much better controlled, before rising again sharply towards telephoto; indeed the value of 0.26% in the blue channel at 200mm F11 represents a new record, and forces a recalibration of the scale in our lens review widget. Ouch!
Falloff We consider falloff to become perceptible when the corner illumination falls to more than 1 stop below the centre. Here we see moderate vignetting wide open at both ends of the zoom range, however this never exceeds 1.3 stops and disappears rapidly on stopping down, so shouldn't really be an issue in normal use.
Setting a brand new record for distortion, the 18-200mm weighs in with a decidedly disconcerting 3.4% barrel at wideangle; this is also a complex, wave-type distortion with re-correction towards the corners. The pattern shifts rapidly to pincushion, peaking at 50mm and -1.9% (again likely to be readily visible in real-world shots) before settling back to more reasonable levels at telephoto.

Macro Focus
Internal focus zooms have generally performed somewhat poorly in our macro tests, and the 18-200mm doesn't break any new ground here. The big surprise though is to find our sample focusing much closer than Canon's specification; closest focus is 34.5cm (with a 14cm working distance from the front of the lens to the subject), giving a maximum magnification of 0.31x (compared to the stated 0.45m and 0.24x magnification).

Image quality isn't too hot though; the centre is never properly sharp at any aperture, and curvature of field also appears rather high, with the corners of our test chart only coming into focus at F22. The image also shows mild barrel distortion, soft corners and significant chromatic aberration (mainly blue/yellow); not a great result at all.

Conclusion - Pros
Huge 11x focal length range, ideal general purpose and travel lens
Excellent image stabilization system, consistently delivering three to four stops benefit
Good central sharpness at all focal lengths (but inconsistent corners)
Attractive rendition of out-of-focus regions of the image
Improved build quality in comparison to the 18-55mm and 55-250mm kit lenses
Well-placed zoom lock switch
Conclusion - Cons
Poor sharpness across much of the frame at 18mm and wider apertures
Pronounced barrel distortion at wideangle, and pincushion distortion around 50mm
High levels of chromatic aberration at either end of the zoom range

Registration date : 01/01/1970

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