How to shoot perfectly sharp photos in less-than-perfect light with a
pro-caliber, digital-only tele.
If you needed proof that Pentax has a high-performance, professional-quality DSLR in the offing, this $1,000 (street) lens is it.
Based on the film-era 200mm f/2.8 FA lens, it's equipped with new internal-flare-suppressing coatings, and it has a newly designed rear element which Pentax claims projects a perfectly flat-field image. A 300mm equivalent, it sports Pentax's SMC supersonic focusing motor for near-silent autofocus action, as well as Quick-shift focusing that lets you touch up focus manually while the lens remains in the AF mode.
Joining the 300mm f/4, 16-50mm f/2.8, and 50-135mm f/2.8, this is the fourth lens in Pentax's DA* family of matched, pro-oriented glass. Fully loaded with water- and dust-repelling gaskets and O-rings, it's a high-speed tele prime that's clearly well constructed and ready for outdoor action.
Surfaced in a faint, matte-black crinkle finish and ornamented with the bright green aluminum ring that signifies a Pentax digital-only lens, this mostly polycarb prime is average in weight and size for the class -- very similar to the Sigma 150mm DG macro lens, for example. (At 1.8 pounds, it's more than a pound lighter than the comparable Olympus 150mm, which also scales up to about 300mm, but that's because the Oly is an f/2).
Although the Pentax is more than 5 inches long, it throws no shadow at close-focus when used with the K200D's built-in flash. It also has plenty of gold ornamentation, a depth-of-field scale, and an extra-deep 3.25-inch lens shade that includes a clever trapdoor ( or finger window) that lets you reach in to fine-tune the positioning of a mounted filter.
IN THE LAB
SQF results showed sharpness and contrast in the Excellent range at all apertures and output sizes. (No surprise there.) DxO Analyzer 3.0.1 tests found near-absolute distortion control, with only Imperceptible pincushion distortion (0.01%) detectable. (This is, in fact, the single best distortion performance we've encountered since adopting the DxO system in 2005.) We found no noticeable light falloff in corners at any aperture. Finally, at the close-focusing distance of 46.75 inches, the maximum magnification ratio was a satisfyingly powerful 1:4.56.
In its superior vignetting- and distortion-control performance, this digital-only tele actually tests very much like the full-frame lenses we've evaluated on DSLRs with APS-sized sensors -- no surprise since its design is based on a 35mm lens. Its high speed and near flawless optics coupled with Pentax's sensor-based image stabilization technology helped us take dozens of satisfying pictures over several weeks of field testing. It promises the pro or serious amateur virtually distortion-free and perfectly sharp pictures, even in less-than-perfect light.
If there's a downside to this lens, we couldn't find it.
200mm (198.33mm tested), f/2.8 (n.a. tested*), 9 elements in 8 groups. Focusing turns 210 degrees clockwise.
• Diagonal view angle: 8 degrees.
• Weight: 1.85 lb.
• Filter size: 77mm.
• Mount: Pentax KAF.
• Included: Lenshood, soft case.
• Street price: $1,000.
*Tested measurement not available due to instrument limitation.