Pentax lenses on Sony Full Frame

<p>I was reading an article (<a href="http://briansmith.com/sony-a7r-field-test/">http://briansmith.com/sony-a7r-field-test/</a>) on a field test of the new Sony FF A-7R.<br>

It came to my attention that you can use Pentax lenses via an adapter on Sony cameras. Has anyone tried this? <br>

The adapter isn't expensive (<a href="http://www.amazon.com/RainbowImaging-Pentax-mount-Camera-Adapter/dp/B003X19WZC/ref=sr_1_cc_1?s=aps&ie=UTF8&qid=1329283364&sr=1-1-catcorr">http://www.amazon.com/RainbowImaging-Pentax-mount-Camera-Adapter/dp/B003X19WZC/ref=sr_1_cc_1?s=aps&ie=UTF8&qid=1329283364&sr=1-1-catcorr</a>)</p>

<p>Malcom, you should look into <a href="http://www.amazon.com/RainbowImaging-Pentax-E-Mount-Camera-Adapter/dp/B00406P7GM/">this adapter as it has 5 steps aperture adjustment</a> that can work with DA type of lens that are without aperture ring. The one you posted only work with lens that have aperture rings. I have the adapter with aperture control for 5 steps. Both Pentax K to NEX adapters are a bit bulky. There is a similar adapter for the M42 lenses and it is even bulkier with a cylinder shape. I don't have the A7 but you can visit <a href="http://www.techtheman.com/">my blog page</a> and see how I use Pentax K mount/M42 mount lenses with Sony NEX cameras.<br>

<br />An alternative way to use the Pentax Full Frame capable FA mount lenses with current nex E mount is with Zhongyi Lens Turbo that is a focal reducer that cancels out the 1.5 crop factor on aps-c and the focal reducer adds 1 extra light of stop. The caveats lie in degradation on corner performance. The advantages are FF field of view and gain of 1 stop of light. You can look up Metabones speedbooster and the Chinese knockoff Lens Turbo. The reason that I mention Lens Turbo is that the adapter is almost like half the length of the Pentax K to NEX adapter.<br>

<br />Using the FA 77 and 43 with the lens turbo is great on my nex 5n and so are the inexpensive SuperTakumar 55mm f/1.8, 35mm f/3.5 and 28mm f/3.5. The gain of 1 stop of light work especially well with slower lens as in f/3.5 and f/2.8.</p>

<p>The Pentax K to NEX adapter is not small and you can see this picture with a FA 43mm for reference<br>

<a title="DSCF2886 by hin_man, on Flickr" href=" src="http://farm7.staticflickr.com/6056/6371585473_6187465ed4_b.jpg" alt="DSCF2886" width="1024" height="489" /></a></p>

<p>And the Leica M, LTM, Pentax Auto 110, Konica AR to NEX adapter are thinner in comparison<br>

<a title="DSCF2884 by hin_man, on Flickr" href=" src="http://farm7.staticflickr.com/6036/6371579415_0282f2a019_b.jpg" alt="DSCF2884" width="1024" height="257" /></a></p>

<p>They all work well in the NEX system and they should work with full frame lenses on A7/A7r in the FE mount. If you mount any DA lenses onto the A7/A7r (the FE mount), a crop mode is required if you don't want the vignette on corners.</p>

<p>Out of all the traditional SLR lenses, the smaller adapter that I know are the Canon FD and Konica AR. The others are similar in size to the Pentax K adapter.</p>

<p>Two links with discussions on adapters with the A7 and A7r</p>

<p>1. <a href="http://blog.nicgranleese.com/2013/10/24/sony-a7r-review-for-architectural-photographers/">http://blog.nicgranleese.com/2013/10/24/sony-a7r-review-for-architectural-photographers/</a></p>

<p>2. <a href="http://www.fredmiranda.com/forum/topic/1248252/0">http://www.fredmiranda.com/forum/topic/1248252/0</a></p>

<p>I am studying the two adapters that come out with A7 and A7r. They will work with AF with Sony Alpha lenses in </p>

<ul>

<li><a href="http://store.sony.com/a-mount-to-e-mount-mount-adaptor-zid27-LAEA3/cat-27-catid-All-Cameras-Alpha-DSLR-Accessories">Sony LA-EA3</a> $199 -- Use this adapter to attach Alpha A-mount lenses to your Alpha E-mount full frame camera body. It includes Auto Exposure support with aperture mechanism and a detachable tripod attachment.<br /><br /></li>

<li><a href="http://store.sony.com/a-to-e-mount-ff-mount-adaptor-w-tmt-zid27-LAEA4/cat-27-catid-All-Alpha-a7-Cameras">Sony LA-EA4 $349</a> with built in SLT -- Attach Alpha A-mount lenses to your E-mount full frame camera body and enjoy full-time continuous Phase Detection AF while capturing stills and video with world's first full frame mount adaptor to be equipped with Translucent Mirror Technology™. Plus, aperture drive mechanism enables Auto Exposure with compatible A-mount lenses3.<br /><br /></li>

</ul>

<p>The latter will work with faster AF with phase detection. It is analogous to the LA-EA1 and LA-EA2 that work with Sony NEX (aps-c cameras).</p>