Pentax 16–50 f/2.8: The Dream Kit Lens…

Pentax SMC-DA* 16–50mm f/2.8 ED (IF) SDM

… until reality struck. The Pentax SMC-DA* 16–50mm f/2.8 ED (IF) SDM has a lot going for it but didn’t quite impress Aditya Nair.

With heavy monsoons, dusty roads, clumsy waiters and ice cream spills, the weathersealed Pentax SMC-DA* 16–50mm f/2.8 ED (IF) SDM survived a lot in the month that it was in my possession. Believe me when I say this lens can handle abuse. When I first got my hands on this lens, it felt like the perfect companion to the K-3, a camera I absolutely adore. However, I quickly began noticing some obvious problems with the lens and the price tag at which it comes.

Features
The 16–50mm (24–75mm equivalent focal length) is one of only two ways to get a fast wide angle proprietary lens on a Pentax APS-C system. The other is the 14mm f/2.8 (21mm equivalent) lens. From third party manufacturers, you have the Tamron 17-50mm f/2.8 XR Di-II LD Aspherical (IF) and the Sigma 17-50mm f/2.8 EX DC HSM (25.5–50mm equivalent). The AF is fast and accurate. The Quick Shift system lets you manually override AF.

The Supersonic Dynamic Motor (SDM) offers near silent AF which the Tamron and Sigma do not do. In a quiet environment, the noise difference between these lenses is stark. It also offers the traditional screw drive AF to support legacy cameras as well. Other features include a min. focusing distance of 0.3m and a distance scale.

Photograph/Aditya Nair

Handling
Weathersealing sets this lens apart from the Tamron and Sigma versions as well as similar proprietary lenses offered by Canon, Nikon and Sony. I can’t begin to explain the joy of shooting in the rain and not having to constantly worry about your gear.

It uses a high density foam rubber to make the system weather, dust and coldproof. On a side note, a Pentax press release on the weathersealing reads, “As hardy as the photographers that use them…” I’m not going to lie. That made me grin.

The lens uses a Super Protect (SP) coating to repel dust, water and grease. This makes cleaning the front of the lens a lot easier. The metal bayonet and high quality plastic make it a sturdy lens. It is slightly heavier and larger than the Tamron but balances well on the Pentax K-3.

The lens has large zoom and focus rings that are convenient. Zooming in, though, feels jerky and I wish it didn’t push out the front element.

Pentax has faced a fair amount of criticism for quality control issues like the SDM failing and back focusing problems with this lens. But this seems to have been resolved now.

Photograph/Aditya Nair

The Lens Hood Conundrum

Photograph/Aditya Nair

The lens hood wasn’t able to minimise flare in instances where it should have (image above). As seen in the image below, I was able to cut the flare by rotating the hood. This caused the hood to appear in the image, but it should have been able to reduce the flare when fixed the right way.

That said, the hood has a removable slot that lets you adjust a polarising filter without having to remove the hood. I wish other lens hoods had this.

Photograph/Aditya Nair

Performance
The optical quality of the lens wasn’t as good as I would have wanted, given the K-3’s 24MP sensor. While the centre sharpness at f/2.8 is good, it deteriorates as you move to the edges. Sure, all lenses suffer from some corner softness wide open, but I expected this lens to be a little better, given its price. The sweet spot for the lens is between f/5.6 and f/8.

The lens uses two ED elements and three aspherical elements to compensate for chromatic and spherical aberration. Yet, fringing is evident when shooting high contrast scenes. It is noticeable throughout the zoom range but is the most at 16mm. Slight vignetting is seen throughout the zoom range, when shooting at f/2.8.

There is a fair amount of barrel distortion at 16mm but reduces quickly as you approach 24mm. At 50mm, you can see slight pincushioning.

Photograph/Aditya Nair

Conclusion
The Pentax has many useful features, its weathersealing and silent focus. But is it worth the Rs. 95,995 price tag? The lens is well priced if you compare it to similar lenses from Canon and Nikon. But the Tamron 17–50mm f/2.8, which I found to be slightly optically sharper is a bit more than one-fourth the price (Rs. 27,800).

As a fellow photographer pointed out to me, if you want weathersealing, you can buy the Pentax 18–55mm kit lens (Rs. 15,995) and the Tamron. It will cover almost 90% of scenarios that you would use this lens in and still cost only a little over half the price of the 16–50mm.

Something doesn’t quite add up. For this reason and because of the overall image quality, this isn’t the lens for me.

Photograph/Aditya Nair