Pentax-DA Rear Converter 1.4x: First Impressions

A hands-on look at the new teleconverter

By PF Staff in Hands-On Tests on Mar 12, 2014

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We received our copy of the new 1.4x teleconverter for test today. Its official name is a somewhat longish HD Pentax-DA 1.4x AW AF Rear Converter. As the name indicates the converter is designed for DA lenses, aka the APS-C format, it magnifies the image by 1.4x, it is weather resistant, and it supports auto focus. What the name doesn't reveal is that it supports screw drive as well as SDM/DC autofocus.

Our first impression is that the build quality is excellent, the quality rivals that of a Pentax DA* lens. If the image quality is up to snuff this converter will earn a spot in our camera bag.

A thorough test is forthcoming of image quality as well as autofocus performance. Our immediate impression when used with a D FA 100mm lens on a Pentax K-3 is that screw drive autofocus is sure footed and as fast as using the lens without the converter.

What we were curious about was if the converter modifies the lens data so that the camera knows what it is dealing with. It does. Third party converters like the otherwise highly regarded Tamron-F 1.4X Pz-AF MC4 do not.

We mounted our smc Pentax-DA*60-250mm F4 lens, set it at 80mm and fully open (F4). Our Pentax K-50 reported the lens as 112mm F5.6, which is correct: Focal length multiplied by 1.4x and one stop of light loss:

Similarly our D FA 100mm F2.8 lens showed a focal length of 140mm and F4 when set to wide open. While the conversion of the F-stop is a nice to have, the conversion of the focal length is a must have for shake reduction to work correctly.

Focal length and F-stop conversion also works with Pentax-F and FA series lenses, whereas there is no F-stop conversion with A-series lenses . A-series lenses, of course, do also not report their focal length to the camera.

Finally, let's take a look at the rear of the converter with the red weather sealing gasket,  the SDM/DC power contacts, the screw drive and the lens information contacts.

We hope you enjoyed this brief summary and stay tuned for our in-depth review.  This teleconverter is now shipping in the us for $599.