Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
06-14-2010, 05:10 PM   #1
New Member

Join Date: Jun 2010
Location: Columbus OH
Posts: 2
K-x and tamron adaptall

I am considering purchasing a K-x. I am the proud owner of a a vintage spotmatic that has taken some great pictures, but just does not get used anymore. Also have a Tamron 103a 80-210 zoom with an adapter for screwmount. Questions are: 1. Does it make sense to try to use this lens with the K-x? 2. I could either get a K adapter (and take the screwmount adapter off), or an screwmount to k adapter and which would be preferable? 3. How much should an adapter cost and are they widely available? Let me know if I am overlooking anything important. Any help appreciated.

06-14-2010, 06:45 PM   #2
Just1MoreDave's Avatar

Join Date: Feb 2007
Location: Aurora, CO
Photos: Gallery | Albums
Posts: 4,864
Your lens appears to be an Adaptall-2 so there are three Pentax-useful adapters you can use. The difference is cost and functionality with the camera.

You can get an M42-K adapter and use your screwmount adapter. I'm not familiar with the Adaptall screwmount adapter but it would need to have the ability to allow the aperture ring control the aperture, like the Manual position on a Super-Takumar lens. The Pentax M42-K adapter is sometimes available from the Pentax webstore for ~$30; copies are ~$15.

There are two Adaptall K-mount adapters. Actually three I think but two only differ in the engraving. Those two are labeled "K,M" or "P/K" and make the lens equivalent to a basic K-mount lens. They sell for $15-25 on eBay. The lens works in M mode with stop-down metering. To save me typing, I'll refer you to the sticky at the top of this section.

The other one is labeled "P/K-A" and has 3 electrical contacts. It allows Adaptall-2 lenses to work like they have the A position on the aperture ring, so the camera can control the aperture. You only get the center focus point. Otherwise, the lens works well with the camera. These adapters sell for much more, ~$80-100. because of the extra functionality.

With all adapters, focus is still manual and you'll have to set the focal length for SR, and reset it when the zoom changes. The AF sensors are active and can confirm focus. I like using interesting old lenses on my Pentax but it can be extra work.

Here's an old thread on the same lens:
06-16-2010, 05:21 AM   #3
New Member

Join Date: Jun 2010
Location: Columbus OH
Posts: 2
Original Poster
Thanks Dave. I had read the link you posted, but was not sure I had pieced it all together. Your reply was concise and on point. Especially helpful was which adapters would work.

  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
adapter, camera, k-x, k-x and tamron, pentax help, photography, screwmount, tamron
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: Tamron 500mm f/8.0 (55bb), Tamron 28-70mm (44a), adaptall-2 p/k, Vivitar 283 f hinman Sold Items 7 03-03-2010 08:42 PM
For Sale - Sold: Tamron Adaptall PKA adapter + Tamron SP 35-80mm F/2.8-3.8 leeak Sold Items 4 11-21-2008 08:23 PM
For Sale - Sold: Tamron Adaptall SP 90 f/2.5 Macro with Adaptall-2 to PKA converter and Extenti cousinsane Sold Items 1 06-22-2008 01:46 PM

All times are GMT -7. The time now is 09:49 PM. | See also:, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]