Why is the Pentax DA* 16-50mm so disappointing?

Pentax DA* 16-50 F2.8 Lens

In the APS-C Pentax world there is nothing more sought after than the DA* series of lenses. Though an argument can be made for the DA Limited series, the DA* lenses offer more traditional focal lengths and fast apertures appealing to a more general audience. But one DA* lens remains the ugly duckling of the group and maintains the lowest scoring DA* lens on PentaxForums user reviews. I think I know why now after using it for a few months.

Pentax DA* 16-50mm F2.8 Introduction

The original Pentax DA* 16-50mm lens was released in 2007. If you need a camera release to properly date that, that’s the era of the Pentax K10D, Canon 40D and Nikon D80. 10 megapixels was all the rage, and we hadn’t yet left CCD sensors entirely. While that may seem like ages ago, in the world of lenses where 1970s glass still shines, it remains a relatively modern lens.

Pentax DA* 16-50mm f2.8 lens
Pentax DA* 16-50mm f2.8 lens

I’m talking about the original DA* 16-50mm lens in this review, and not the new revamped DA* 16-50mm lens released in 2021. It’s a totally new optical design and focusing motor and seems like a real winner. This older one… well… you’ll see.

Why 16-50mm? Well, it’s a standard fast zoom, something equivalent to a 24-70mm f2.8 on full-frame in terms of focal length and light gathering ability. Other brands have similar lenses for their APSC systems. It’s a focal length I don’t gravitate towards, despite being practical. I’m more of a prime shooter. (Try saying that without sound pretentious). But it’s true! For whatever reason zooms throw me off.

Please note that while some DA* lenses actually do cover a full-frame, this one does not at any focal length/aperture. So no sneaking a double use out of this lens.

What’s good about the lens?

There’s a lot to like about the lens. 16-50mm is a great APS-C focal length for a wide variety of shooting situations. A 24-70mm equivalent in full-frame terms. The fast constant aperture of f2.8 gives you more flexibility to shoot under low light conditions, and also gives nice bokeh when you want it.

Pentax DA* 16-50mm f2.8 lens front element
Pentax DA* 16-50mm f2.8 lens large front element with 77mm filter thread

The lens is sharp in the center from wide open and gets quite sharp stopped down. I didn’t have any major issues with the sharpness when stopped down for landscapes. Wide open in the center was good for portraits.

Another nice feature of the lens is the weather sealing, which is rated as all-weather (AW) for Pentax. Since Pentax bodies are almost all weather sealed this is a nice combination.

What is not so good?

But, it’s not all good. Focusing on the lens is slow and using the old SDM motors which are prone to failure. Luckily, you can do a firmware conversion to have the lens revert to a screw drive focusing system if that ever happens to you. I did this on both my DA* 50-135mm and DA* 300mm F4 lens. Surprisingly, the SDM of the 16-50mm lens continues to live on for me.

Beyond the autofocusing the main complaint users have about this lenses performance is chromatic aberrations. This is shown best in this PentaxForums review comparing the lens to the Sigma 17-50mm f2.8. There you can click on side-by-side zoomed in examples. Clearly the Pentax DA* 16-50mm underperforms in the comparison, with the chromatic aberrations affecting visible sharpness. However, in my use with this lens I didn’t find it to perform embarrassingly in this regard. Certainly worse than the DA* distinction would lead you to believe, but not embarrassing.

Reason for being the least liked DA* lens

Beyond the lens performance, the original Pentax DA* 16-50mm has two major problems preventing overwhelming success. The first is the original list price of just over $1,000 USD. A price that is consistent with other high-end zooms, but lends itself higher expectations. Those expectations of performance aren’t always met as described above. The second problem is related. The Sigma 17-50mm f2.8 for Pentax K mount is a readily available third-party alternative lens. This lens by all accounts is sharper, faster focusing, and deals with CA better. And then if that wasn’t enough, it is also cheaper than the DA* counterpart.

I think the DA* 16-50mm f2.8 would have faired better were it not for the high release price and DA* designation leading to higher expectations. I find the lens to be quite nice, actually. But I was going in with lower expectations based on what I had heard. Now for around $200 USD you can get the lens on the used market. That makes the lens a much better deal. If you don’t need weather sealing or some of the other features, the all-round better performing Sigma 17-50mm is also around $200 USD.

Conclusion

While the DA* 16-50mm F2.8 may be the least liked Pentax DA* lens (according to PentaxForums user scoring) I find it to be a nice lens. The trick is to get it with lower expectations. It makes for a fine fast zoom that is sharp when stopped down and produces bokeh wide open. While there are flaws about this lens, it’s not in the same category as cheap zooms from the 90s. Some of those can be disastrous quality. This is not the case here.

I’m glad to hear the new PLM version is not only a new fast focusing system, but also an upgraded optical formula and coatings. It seems to be more worthy of the DA* designation and high price. I wonder what could have been if this lens was listed for just a few hundred less than it was…

Until next time, happy snappin’


James Warner

James Warner

Avid photographer with a passion for finding older forgotten digital cameras and proving they can still make beautiful images. I like to get up early, stay up late, and bike through mud to get a great picture. Support my work: https://www.buymeacoffee.com/snappiness

One Comment

  1. Great writeup.

    I love my Sigma 17-50mm.

    I often read how sharp a lens is only to be mildly impressed. My Sigma though, exceeds what little hype it gets.

    Third party lenses lack weather sealing but I figure for the number of times I actually shoot in bad weather, I can’t justify paying for an entire line of WR lenses. If I bought a 18-135 for the occasional downpour I’d be covered and not feel the need to treat it to dearly. The cheaper third party performers will easily handle the rest!

    Love the articles btw

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