Morry Loc: Palm Springs, CA

I have an old Tamron SP 17mm Adaptall lens fitted with a Tamron Adaptall P/KA Pentax K mount. Would it be possible to additonally add a Pentax K mount to Sony E mount adapter (available on Amazon & E-Bay) to use on my Sony a6000? The lens is in mint condition and not being used. It may be a bit of a stretch to use 2 adapters. What are your thoughts on this. Thanks for any replies.

JimH123 Loc: Morgan Hill, CA

I don't see why not. The Adaptall P/KA K mount adapter causes the lens to be positioned to exactly the same distance as a regular K-Mount lens would need and the Pentax-K to Sony E-mount adapter takes care of the secondary adaptation. Should work.

rmalarz Loc: Tempe, Arizona

I wouldn't count on it. There seems to be something about adapting an adapter in this manner. It might work, but I'd be surprised if it did.
--Bob

G Brown Loc: Sunny Bognor Regis West Sussex UK

If they are the cheap adapters (no electronics) then give it a try. You have 'through the lens' view and the ability to double up to get a true focus. The sony adapter will keep your camera safe and the other adapter has no ingress. However, old lenses are not usually renown for being good at all things so treat with that in mind when viewing the results. Like macro and extension tubes, there will be 'a spot' where they are great....its just a matter of finding it.

amfoto1 Loc: San Jose, Calif. USA

Rather than stacking an adapter on top of the existing Adaptall, why not just replace the Adaptall mount on the lens with one to fit your camera?

Check eBay... I bet someone in China is making Adaptall interchangeable mounts to fit your Sony.

I bought one for Canon EOS/EF mount... for a Tamron 90mm macro Adaptall lens. It cost about $40 incl. shipping, arrived in 4 or 5 days and works fine. It's the chipped version that supports Focus Confirmation on Canon cameras (unchipped are cheaper, around $25-$30). I don't know if Sony use similar chipped and unchipped versions of Adaptall.

But, if need be, I suspect that adding a Pentax to Sony adapter also would work fine. That's because what's on the lens now actually isn't an adapter... it's an interchangeable mount on a lens specifically designed to use interchangeable mounts. Adding an adapter to this Tamron would be no different than adding an adapter to any other Pentax P/K lens with non-interchangeable mount.

imagemeister Loc: mid east Florida

YES, it will work ....

whitewolfowner

If you are adding an adapter to an adapter, it will act like an extension tube and you will lose infinity focus. If you are describing what I think you are describing, remove the first one and put on the second one and everything will be fine. So, the answer is, no, it will not work as you are asking. Too many here have no idea what they are talking about!

bwana Loc: Bergen, Alberta, Canada

Works like a charm with all my ol' Tamron Adaptall/Pentax K mount lens!

You can also get Tamron Adaptall -> E-mount adapters and bypass the Pentax K adapter; several available: https://www.fotodioxpro.com/tamron-adaptall-ii-lens-adapter-for-sony-e-series-camera-fits-sony-nex-3-nex-5-and-nex-vg10-video-handycam-camcorder.html. Just a word to the wise, there are two different Tamron Adaptall styles. Be sure you know which it is you have?

bwa

whitewolfowner

Something new; not what I understood was being asked. Has to be some loss somewhere. Said uses sweet spot of lens, so it must magnify the field of view; not desirable in a wide angle lens. Like putting a wide angle FX lens on a DX camera, is what it looks like to me. Why not just remove the Pentax mount and get one for Sony (if they make it); then it will work like a 17mm lens and more like a 28, 35 or who knows what?