Tamron AF 18-200mm f/3.5-6.3 XR Di II LD Aspherical (IF) Macro Zoom Lens for Pentax Digital SLR Cameras

by Tamron

Product Details

• Product Dimensions: 9 x 9 x 9 inches ; 14.1 ounces
• Shipping Weight: 1 pounds (View shipping rates and policies)
• Shipping: This item is also available for shipping to select countries outside the U.S.
• ASIN: B0007WK8NK
• Item model number: Pentax AF
• Average Customer Review: 3.8 out of 5 stars  See all reviews (150 customer reviews)
• Date first available at Amazon.com: February 24, 2005

Product Description

Style: Pentax

From the Manufacturer

Tamron's original development of proprietary core technologies such as Aspherical element production, Multiple Cam Mechanism and Integrated Focus Cam design lend to the creation of the world's lightest, most compact 11x zoom lens made for digital SLR cameras.

Zoom in for a macro shot

AF18-200mm F/3.5-6.3 XR Di II Highlights

Di II
Lenses are designed for exclusive use on digital cameras with smaller-size imagers and inherit all of the benefits of our Di products. These lenses are not designed for conventional cameras and digital cameras with image sensors larger than 24mm x 16mm.

Extra Refractive Index Glass (XR)

Special glass for better performance and more compact lens designs

Extra Refractive Index (XR) glass can bend light rays at steeper angles, thereby decreasing the physical length of the lens while enhancing imaging performance by minimizing optical aberrations. This has allowed Tamron to develop a line of shorter, smaller-diameter, lighter lenses without sacrificing lens speed, and actually upgrading image quality compared to older designs. XR glass is costlier than conventional glass but it yields enhanced optical power distribution, making possible many of the outstanding and innovative lens designs that bear the XR designation. XR glass, with its superior light-bending power, makes it possible to design a short-barrel lens with the same light-gathering ability (aperture value) as a long-barrel lens—even with a smaller lens diameter. By using this principle Tamron has been able to shorten the length of the entire optical system and produce lighter, more compact lenses of the same speed, and also to provide greater zoom ranges in lenses that are much more convenient to carry by hand.

Low Dispersion (LD)
Low dispersion (LD) glass elements in a lens help reduce chromatic aberration; the tendency of light of different colors to come to different points of focus at the image plane. Chromatic aberration reduces the sharpness of an image, but glass with an extremely lowdispersion index, has less of a tendency to separate (defract) a ray of light into a rainbow of colors. This characteristic allows the lens designer to effectively compensate for chromatic aberration at the center of the field (on axis), a particular problem at long focal lengths (the telephoto end of the zoom range), and for lateral chromatic aberration (towards the edges of the field) that often occurs at short focal lengths (the wide-angle end of the zoom range.)

Low Dispersion (LD) Glass for Greater Lens Sharpness

Internal Focus (IF)
Internal focusing (IF) provides numerous practical benefits to photographers including a non-rotating front filter ring that facilitates the positioning of polarizing and graduated filters, and more predictable handling because the lens length does not change during focusing. Even more important, Tamron’s Internal Focusing (IF) system provides a much closer minimum focusing distance (MFD) throughout its entire focusing range. In addition, IF improves optical performance by minimizing illumination loss at the corners of the image field, and helps to suppress other aberrations that become more troublesome at different focusing positions.

Zoom Lock
Another original Tamron mechanical engineering concept is the Zoom Lock (ZL), a simple convenience feature that prevents undesired extension of the lens barrel when carrying the camera/lens unit on a neck strap.

Product Description

The new AF18-200mm F/3.5-6.3 XR Di-II LD Aspherical (IF) MACRO is a high power zoom lens for exclusive use with digital (APS-C size) SLR cameras that inherits the product concept of the existing AF28-300mm F/3.5-6.3 XR zoom lens. Even two years after its introduction, the current AF28-300mm is still a much loved and highly evaluated by photographers around the world as a representative model of high power zoom lenses. With the market influx of digital SLR cameras in recent years, the use of high power zoom lenses has become increasingly popular since high power zooms provide the convenience of handling many photographic scenes and the capability of shooting ultra telephoto shots without changing lenses. The popularity of this focal length led Tamron to initiate the development of new zoom lenses to further meet the needs of digital SLR photographers.

Customer Reviews

Most Helpful Customer Reviews

297 of 301 people found the following review helpful:

4.0 out of 5 stars Good value - useful all-in-one lens, August 9, 2005

By 

A. C. Sisto "Educated Amateur" (Orange County, CA) - See all my reviews
(REAL NAME)   

This review is from: Tamron AF 18-200mm f/3.5-6.3 XR Di II LD Aspherical (IF) Macro Zoom Lens for Canon Digital SLR Cameras (Camera)

Like a baseball player with a decent batting average, some power, a little bit of speed and fairly good fielding ability, the Tamron 18-200 lens won't be an All-Star any time soon because it does not excel at any one thing. But, like that $500k/year utility infielder, this lens DOES provide a very good all-around value for what it is. Does it compare to a prime lens at either end? Heck, no. Is it a good lens to use when you can't carry a wide choice of lenses with you? Absolutely.

I've been using this lens on my 20D quite a bit and have only a few minor gripes: it tends to hunt for AF (especially as you get closer to 200mm), and it's not the quietest lens I've used.

An earlier reviewer mentioned that it maxed out at about 160mm. My own analysis shows that it is short of 200mm, but not by that large an extent; I found it much closer to 190. Still, there's no doubt that these zoom lenses with extreme ranges like this have a built-in fudge factor.

Another reviewer described the problems he encountered when using two screw-on filters. There aren't too many primes that I've used that will avoid vignetting when using two filters. Heck, my 10-22 can barely handle one extra-slim. As for darkening the image - well, you're adding two more pieces of glass to a highly-complex lens assembly... just asking for trouble.

As for the concern regarding blur at longer focal lengths, I highly recommend the use of a tripod. I noticed the exact same thing - blur and lack of sharpness - at lengths over 100mm. Keep the old rule of thumb in mind - if you're shooting handheld, your shutter speed should be no slower than the inverse of your focal length. A 200mm lens on a 20D (or Rebel XT for that matter), is an effective 320mm - I wouldn't recommend shooting any slower than 1/500 at max zoom with this lens - UNLESS you're using a tripod. When I mounted it firmly, I got great shots with no blur.

Keep in mind that you get what you pay for here: the convenience of a wide-angle, normal, and moderate telephoto lens in one piece. If you're shooting professionally, or need absolutely perfect images, then carry the three or four lenses that this would otherwise replace in your bag. But if you want one easy-to-use, satisfactory lens, go for this one. It's a jack-of-all-trades, ace-of-none kinda deal.

84 of 85 people found the following review helpful:

5.0 out of 5 stars Never ceases to amaze, June 27, 2006

By 

mcenut (North Salt Lake, UT) - See all my reviews

This review is from: Tamron AF 18-200mm f/3.5-6.3 XR Di II LD Aspherical (IF) Macro Zoom Lens for Canon Digital SLR Cameras (Camera)

I have owned this lens for over a year now and it never ceases to amaze me when I see the photos it produces. Over this last year I have come to learn a thing or two about how to use this lens.

1) If you are going to shoot indoors, or in low light, with a long focal length (like 200mm) use a tripod or plenty of ambient light. This lens doesn't have a built in image stabilizer so you are going to steady the lens with the tripod or use a real fast shutter speed to minimize your hand jitter.

2) Use a smaller aperture. I have found that my best photos come from an aperture of 8.0 thru 16. These apertures aren't great for bokeh (background blur) but they sure do allow you to take razor sharp pictures.

Praise.

Focal range. With one lens you are able to take nice wide-angle shots (18mm) and with the twist of zoom ring you have a nice telephoto lens (200mm) Definitely a good walk around lens for the day at the botanical gardens, museum or amusement park.

Build quality. This lens gives you a nice solid feel in your hands. Give it a shake and it doesn't make a sound. The zoom and focus rings move smoothly without being sloppy. With a lens this well built you would expect it to be heavy. Not so with this lens, it's quite light (which is something you really appreciate after a long day of carrying it around.)

Minimal chromatic aberrations. The lens' three hybrid aspherical elements and two low dispersion glass elements correct for almost all lateral and on-axis aberrations making most of your images optically clear.

Size. At it's lowest focal length (18mm) the lens is small enough to fit into a mid size top loading camera bag while still attached to the camera body.

Complaint?

Well yes, I do have one minor complaint about the lens. Auto focus is slow. How slow? Well let's just say you won't want to try and photograph a two year old on the move. I have found that I can keep fast moving objects in better focus by switching to manual.

102 of 107 people found the following review helpful:

4.0 out of 5 stars Great all use lens, April 20, 2005

By 

S. Mingus (Los Angeles, CA) - See all my reviews
(REAL NAME)   

This review is from: Tamron AF 18-200mm f/3.5-6.3 XR Di II LD Aspherical (IF) Macro Zoom Lens for Canon Digital SLR Cameras (Camera)

I recently purchased this lens for use on my Canon 20D. I was never happy with the lens that came with the camera. I've been very happy with this lens.

Pros:

- Quality construction. The lens doesn't feel cheap.

- Zoom range of this lens is fantastic.

- Image quality is great.

- Internal focusing makes using filters and hoods a piece of cake

- Zoom lock is nice so the zoom ring doesn't turn while stored or carried.

- Price. For the money this lens will give you a lot of bang for the buck.

Con:

- Auto focusing is a bit slow for a moving subject.

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