Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
05-22-2010, 03:59 AM   #1
Inactive Account




Join Date: Feb 2010
Photos: Gallery
Posts: 488
1.4 sigma apo teleconverter and 300 da*

Will my sigma 1.4 apo teleconverter work with the pentax 300mm da* lens.
Thanks

05-22-2010, 04:39 AM   #2
Veteran Member
dgaies's Avatar

Join Date: Oct 2009
Location: Maryland / Washington DC
Posts: 3,917
QuoteOriginally posted by garyk Quote
Will my sigma 1.4 apo teleconverter work with the pentax 300mm da* lens.
Thanks
There are two issues.

As I recall, the Sigma 1.4x has a somewhat protruding front element which may or may not interfere with the rear element of the DA*300. That said, there is a fair amount of space between the mount and the rear element on the DA*300 (around 1.5-2cm if I recall correctly), so it may physically fit.

The second issue is that you would lose autofocus on the DA*300, regardless of whether or not you can physically mount the 1.4x.
05-22-2010, 05:16 AM   #3
Veteran Member
Eruditass's Avatar

Join Date: Jul 2009
Location: Pittsburgh, PA
Photos: Gallery | Albums
Posts: 2,206
Even though the DA* has both focus capabilities? that sucks.

Are the Sigma TC's notably better than other brands optic wise (despite their incompatibilities)?
05-22-2010, 05:41 AM   #4
Veteran Member
dgaies's Avatar

Join Date: Oct 2009
Location: Maryland / Washington DC
Posts: 3,917
Maybe someone else can chime in and correct me if I'm wrong, but I'm pretty sure that on an SDM ready body the camera won't revert to screw-drive with the TC on.

On an older body (pre-SDM) I'm not sure what would happen.

I haven't actually used the Sigma 1.4x TC so I can't comment directly on the IQ. I have used the Tamron 1.4x Pz-AF on several different lenses (including the DA*300) and I feel the IQ is pretty good. The SDM focus is retained when using the Tamron, although the AF tends to hunt a little more and doesn't always lock on the first try.


QuoteOriginally posted by Eruditass Quote
Even though the DA* has both focus capabilities? that sucks.

Are the Sigma TC's notably better than other brands optic wise (despite their incompatibilities)?


08-01-2010, 08:22 PM   #5
New Member




Join Date: Oct 2009
Location: Millersville, MD
Posts: 6
Sigma 1.4 teleconverter on 300mm DA Pentax lens

The Sigma teleconverter works fine with the latest Pentax 300mm telephoto in terms of fit and optics. I just received both but am having a problem with the converter mounting pin not snapping into place on the lens side. I don't yet know if this is an isolated issue. The pin and hole have very narrow tolerance.

I have only one lens that I can place over the teleconverter besides the 300mm and that is a Sigma lens, which clicks into place over the converter. Filing the pin down might work, but i need to keep my exchange options open while I investigate the matter...

For the record, I do want to boot Hoya in its posterior for not selling their teleconverter in the US. Perhaps Pentax's announcement in 2008 was based on that possibility, but Pentax's parent company chooses to sell the teleconverter only in Japan. Hence, given that Tamron and Hoya have both walked away, I am loathe to bash Sigma for at least supporting us.
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!
apo, da*, k-mount, pentax lens, sigma, sigma apo teleconverter, slr lens, teleconverter
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
I'm Traveling, Want Inexpensive Telephoto Zooms : Pentax 55-300 Or Sigma 70-300 APO Christopher M.W.T Pentax SLR Lens Discussion 32 01-01-2010 07:48 PM
Sigma 100-300 APO vs New Pentax 300 dylansalt Pentax SLR Lens Discussion 10 07-24-2008 05:44 AM
For Sale - Sold: Quantary 70-300 f4-5.6 LDO Macro (AKA Sigma 70-300 APO) K10Perry Sold Items 6 02-25-2008 09:39 PM
Pentax FA J 75-300 lens vs. Sigma 70-300 APO DG Clem Nichols Pentax SLR Lens Discussion 2 04-09-2007 07:51 AM
Advice please: Have K10D - Pentax 50-200 + teleconverter or Sigma 70-300 APO DG? pax1231 Pentax DSLR Discussion 24 03-31-2007 08:42 AM



All times are GMT -7. The time now is 05:48 AM. | 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