Forgot Password
Pentax Camera Forums Home

Show Printable Version Search this Thread
07-03-2012, 07:16 PM   #1
New Member

Join Date: Apr 2012
Location: Toronto
Posts: 5
will manual converter damage my auto focus lens?

Love my k20D and Tamron AF 28-300 XR lens. and I am always curious

I have a Soligor 3x K mount manual TC, and curious to see what is "possible".
How much "clarity" over long distances.
Not looking for gallery-quality pix, just fun and curiosity....... and a Pentax learning experience.

I tried my 3x TC with Tamron 135/f2.8.--- minimally ok results.
Then, I tried 3x TC with manual QuantaRay 35-200, again minimally "ok" results .
I "leaned" against a wall and hand held. Maybe next time the tripod.
I'll only get out the tripod if this becomes obsessive.
( QuantaRay at 200mm is a bit soft anyway ! ) Subject was 400 meters distant.

Even in strong sun there's not much light hitting the sensor..... 1/200, aperture wide open, iso 3200
Focus infinity.... which simplifies the task.

Next I'd like to add my manual 3x to my Tamron AF, focus manually, Mode M or Av.....long end would yield 900 mm.
( I know.... Tamron is also a bit soft at 300mm and Soligor is not a high quality TC )

Question : Is there a risk that I could damage my Tamron AF lens by using manual 3x TC with it ?

Just for the record, I still have all my old M42 lenses (Yashica 50/1.4, Takumar 28/3.5) and a few other K mounts, including Ricoh 50/f2.

Any comments and suggestions are welcomed. And I would enjoy hearing from any Pentaxians in the Toronto area who have tried similar TC and prime lens combinations.

07-03-2012, 07:32 PM   #2
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Oregon
Photos: Gallery | Albums
Posts: 10,749
Only risk would be if the rear element of the lens can hit the front element of the TC. Some TC's (Sigma APO) have glass that is too close to the front to work with all lenses. I seriously doubt that would be the case with a 3x but you should look first. Other than that, no.

You already realize the IQ will be very poor but as you say it might be fun. Check out the 300mm plus lens club for some good advice on shooting with extreme telephoto lenses. It is a real skill to be able to shoot with long glass and get any kind of image.

  • 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!
af, auto focus, bit, camera, focus, lens, pentax help, photography, tamron, tc
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Similar Threads
Thread Thread Starter Forum Replies Last Post
10 Reasons why manual focus primes are better than those new auto focus zoom lenses JoepLX3 Pentax SLR Lens Discussion 188 07-25-2012 03:28 PM
For Sale - Sold: Cheap M42 lenses and BOWER 2x auto focus converter alanjoke Sold Items 5 01-01-2012 11:47 PM
2X auto Focus converter sqjaw Pentax SLR Lens Discussion 2 05-24-2011 04:34 PM
Auto tele converter to manual lens? COULDBE2 Pentax SLR Lens Discussion 5 08-11-2010 03:28 PM

All times are GMT -7. The time now is 11:14 AM. | 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]