Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
01-04-2011, 03:56 PM   #1
Junior Member




Join Date: Sep 2009
Location: Seattle
Posts: 44
Teleconverter Choices?

I don't see a good compilation of this in the lens database, and B&H/Adorama come up surprisingly empty when it comes to K-mount teleconverters.

I'm going to be taking a nice, long, much-needed vacation soon with family, and one of the objectives is bird watching. I'm thinking about picking up the DA* 300mm for the job, but would like a bit more reach if possible.

Since all of this will be in broad daylight, the loss of a stop or two is fine by me, but optical quality is pretty darned important, as is SDM compatibility with the DA*'s.

What are my choices in this regard, and what are your experiences with the different teleconverters?

01-04-2011, 04:12 PM   #2
Veteran Member
dgaies's Avatar

Join Date: Oct 2009
Location: Maryland / Washington DC
Posts: 3,917
There aren't too many options. I've used the Tamron 1.4x Pz-AF with decent success on the DA*300. The AF isn't as fast and sometimes takes a second try to lock, but the IQ is pretty decent overall. The Pentax 1.7x AF Adapter should also give you good results. You won't be using the SDM motor for AF, but the TC itself does the auto-focusing via the screw drive. You'll generally have to manually focus close and then the 1.7x AF-A can lock it in from there, although with the DA*300 you can usually leave it close to infinity focus and the 1.7x will be able to cover most focal distances (with the exception of close focus shots where you would need to manually move the focus ring to a closer focus position before locking in with the 1.7x AF-A.

Other than that, I think there is a Kenko 1.5x that is similar to the Tamron 1.4x, but I've never personally used it. At the end of the day, you might get equal or better IQ cropping, but I can't say for certain since I've never done a direct test to try and validate that.
01-04-2011, 04:19 PM   #3
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,312
there is not a lot of options

the best in my view is the SMC-F 1.7x AF converter. using this gives you rough manual focus plus fine focus in AF through the moveable elements of the converter.

I use the converter on my SMC 300F4 manual focus lens and have had great success. I have had the converter since 1991
01-04-2011, 05:08 PM   #4
Site Supporter
Douglas_of_Sweden's Avatar

Join Date: Apr 2008
Location: Stockholm
Photos: Gallery
Posts: 3,347
Optically the SMC Pentax-A 2x-S converter is marvellous. Probably applies to the corresponding 1.4x as well. Still available new from stock. But non of them are AF. But I have never seen any other converter with less degreding effects.

Reply

Bookmarks
  • 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!
k-mount, pentax lens, slr lens, teleconverters
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Landscape Some help with choices....which one is best??? Rense Post Your Photos! 14 03-06-2010 10:07 AM
Choices Choices! Kai Troubleshooting and Beginner Help 24 07-09-2009 11:02 PM
choices choices forestG Pentax SLR Lens Discussion 7 12-15-2007 05:00 AM
<F/2 choices? Buschmaster Pentax SLR Lens Discussion 10 05-15-2007 10:40 AM
please help.. hopefully down to final 2 choices... slip Pentax SLR Lens Discussion 0 11-13-2006 08:28 PM



All times are GMT -7. The time now is 06:01 PM. | See also: NikonForums.com, 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?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top