Pentax lenses - what adapter to buy?

Discussion in 'Adapted Lenses' started by agnieszka, Mar 2, 2016.

  1. agnieszka

    agnieszka Mu-43 Regular

    71
    May 1, 2015
    Central Coast, NSW Australia
    Agnieszka
    Hi,

    So i have these two Koboron-branded Pentax-mount lenses someone gave me a couple of days ago. not 100% sure what adapters to buy i think they're two slightly different mounts, but not sure if they're compatible a single adapter. Both lenses have a macro option by swivelling a portion of the barrel as well as zoom by swivelling a different portion of the barrel.

    i did a little bit of reading and apparently there's a 'pin' problem where some pentax mount lenses might not unmount so am mainly looking to avoid this with the appropriate adapter, though i'm not sure these lenses apply they do have a weird looking protrusion on the mount, so just want to make sure!
    Any help appreciated.

    One lens states "P/K-A.R" on the back and the other "P/R", as shown in the pictures.

    20160302_211007. 20160302_210920_crop. 20160302_211128_PR. 20160302_211139_PKAR.

    Thanks everyone.
     
  2. HarryS

    HarryS Mu-43 Top Veteran

    921
    Jun 23, 2012
    Midwest, USA
    Look like Pentax KA mount to me. I can see the electrical pins there. A Pentax K to M43 adapter should work as you're not using those pins. The P/R could refer to Ricoh. The KA changed to KAF when they put motors in the lenses and used a shaft from the camera to turn them. Some Ricoh lenses got stuck on that shaft. They can't get stuck on an adapter, but do take warning if you give them to a Pentax user.

    I used to be a Pentax user. Still have a Pentax DSLR and some lenses. Don't use it any more. 2007 technology and a 6MP sensor that was a dust magnet. Anyway, try a cheap Pentax K adapter.
     
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  3. Petrochemist

    Petrochemist Mu-43 Top Veteran

    653
    Mar 21, 2013
    N Essex, UK
    Mike
    P/K-A.R & P/R do indeeded both refer to the Rioch varient mount. AS you say the Rioch pin can catch on the autofocus drive of Pentax cameras, but not an issue with adapted lenses.
    With lenses that have aperture rings any PK type adapter will be fine. I have started using EOS to PK adapters so I can use a wider variety of adapters, having 3 specialist (focal reducing , macro helicoid & tilt) ยต4/3 to EOS adapters. I can also use these adapters with most other legacy lenses by simply getting EOS-mount x adapters. FWIW I don't have any EOS lenses :)

    My newer Pentax lenses that don't have aperture rings are generally kept for use on DSLRs, as I find the DA adapter I have doesn't have very good control of aperture via it's linkage.
     
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  4. agnieszka

    agnieszka Mu-43 Regular

    71
    May 1, 2015
    Central Coast, NSW Australia
    Agnieszka
    Thank you both. Cheap adapter on it's way. Will be here late next week. Very keen to try the 28-200 especially.

    Sent from my GT-I9505 using Tapatalk
     
  5. barry13

    barry13 Super Moderator; Photon Wrangler

    Mar 7, 2014
    Southern California
    Barry
    Don't forget to disable IBIS when using adapted zooms.
     
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  6. agnieszka

    agnieszka Mu-43 Regular

    71
    May 1, 2015
    Central Coast, NSW Australia
    Agnieszka
    Thanks for the tip. I've not delved into learning the different types and effects of image stabilisation options/features yet (still very much a beginner) so never would have thought of this myself - i have other manual lenses and i wonder if this would make shooting with those easier too... only practice will tell! :)

    Sent from my GT-I9505 using Tapatalk
     
  7. barry13

    barry13 Super Moderator; Photon Wrangler

    Mar 7, 2014
    Southern California
    Barry
    Hi, with adapted primes, it's best to manually set the Focal Length (FL) in the IBIS settings, but with zooms you're better off disabling IBIS unless you're going to stick to a single FL (which you should set).

    Barry
     
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