Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
01-30-2010, 09:00 PM   #1
New Member




Join Date: Jan 2010
Location: Montreal
Photos: Gallery
Posts: 7
Teleconverter for DA*300mmF4 ED IF HSM

I just bought a DA*300mmF4 ED IF SDM and I am contemplating buying a teleconverter, either a 1.4X or a 2.0X.

I have a K20D

What high quality 1.4X TC's are available ? What functions do they maintain or not maintain on my K20D ?

Same questions for the 2X TC.

Thanks for your help

Ed

01-31-2010, 12:28 AM   #2
Loyal Site Supporter
Loyal Site Supporter
imtheguy's Avatar

Join Date: Mar 2009
Location: Virginia Beach
Photos: Gallery | Albums
Posts: 2,950
You should be able to find a number of old threads on this topic but I can give you my summary right quick. The only semi-readily available 1.4x TC that supports AF is the Tamron Pz-AF MC4. Even with that one AF can be spotty. I use it on bright days only. I don't know of a 2x TC that actually auto focuses with the DA*300mm.
01-31-2010, 06:36 AM   #3
EdB
New Member




Join Date: Jan 2010
Location: Montreal
Photos: Gallery
Posts: 7
Original Poster
Thank you Lee
I will also review the old threads
Ed
02-01-2010, 04:08 AM   #4
Loyal Site Supporter
Loyal Site Supporter
AdrianM's Avatar

Join Date: Aug 2008
Location: Ipswich, Queensland, Australia
Photos: Gallery | Albums
Posts: 567
The TCs that I know to be compatible with the DA*300 are the Kenko Pz 1.5x TELEPLUS SHQ or the Tamron 1.4X Pz-AF MC4. I own both of these and they work well on the DA*300, although autofocus sometimes hunts unless light is reasonably strong, so for chasing birds in flight I usually resort to 'catch in focus'. I don't think these can be bought new. I bought mine second hand. These also work with other SDM lenses such as the Sigma 70-200 f2.8 II HSM.

Don't confuse the two TCs above with the P-AF 1.5X TELEPLUS MC which is still available new. The P-AF dos not have the SDM contacts.

02-01-2010, 07:57 AM   #5
Loyal Site Supporter
Loyal Site Supporter
imtheguy's Avatar

Join Date: Mar 2009
Location: Virginia Beach
Photos: Gallery | Albums
Posts: 2,950
Thanks Adrian for the quick lesson on 1.5x TCs. I never knew how to specify which Kenko 1.5x supported SDM until now....same as the Tammys, just look for Pz in the name as there is also the Tamron 1.4x that does not work and whose title does not contain Pz.

edit- Adrian, may I ask which of the two Pz models you would choose for your DA*300 as the more consistant focusing and/or better IQ of the two? Thanks.

Last edited by imtheguy; 02-01-2010 at 08:03 AM.
02-01-2010, 07:59 AM   #6
Veteran Member




Join Date: Jan 2009
Location: Canada
Posts: 1,255
QuoteOriginally posted by imtheguy Quote
Thanks Adrian for the quick lesson on 1.5x TCs. I never knew how to specify which Kenko 1.5x supported SDM until now....same as the Tammys, just look for Pz in the name as there is also the Tamron 1.4x that does not work and whose title does not contain Pz.
Also look for "SHQ". I have a Kenko Pz teleconverter with the power zoom connectors but not the "SHQ" version and it doesn't work with SDM.
02-01-2010, 08:09 AM   #7
Loyal Site Supporter
Loyal Site Supporter
imtheguy's Avatar

Join Date: Mar 2009
Location: Virginia Beach
Photos: Gallery | Albums
Posts: 2,950
QuoteOriginally posted by asdf Quote
Also look for "SHQ". I have a Kenko Pz teleconverter with the power zoom connectors but not the "SHQ" version and it doesn't work with SDM.
Thanks for the update.

Ed, you are now ready to look for a 1.4x or 1.5x TC.
02-01-2010, 09:55 AM   #8
Moderator
Site Supporter
Blue's Avatar

Join Date: Jun 2008
Location: Florida Hill Country
Photos: Gallery | Albums
Posts: 17,214
QuoteOriginally posted by imtheguy Quote
You should be able to find a number of old threads on this topic but I can give you my summary right quick. The only semi-readily available 1.4x TC that supports AF is the Tamron Pz-AF MC4. Even with that one AF can be spotty. I use it on bright days only. I don't know of a 2x TC that actually auto focuses with the DA*300mm.
It actually depends on whether you mean AF or SDM AF. This is where the confusion comes in. There are several good AF options out there for screw drive AF, just not SDM.

02-01-2010, 09:59 AM   #9
Veteran Member




Join Date: Jan 2009
Location: Canada
Posts: 1,255
QuoteOriginally posted by Blue Quote
It actually depends on whether you mean AF or SDM AF. This is where the confusion comes in. There are several good AF options out there for screw drive AF, just not SDM.
The Kenko+DA* 300 f/4 combination I mentioned has no AF whatsoever and it only confuses K20D: the Fn menu disappears after a second and the focus indicator does not work.
02-01-2010, 10:02 AM   #10
Veteran Member
borno's Avatar

Join Date: Nov 2006
Location: md-usa
Photos: Gallery | Albums
Posts: 2,580
I tried two different kenko 1.5x pz-shq TC's on my DA300mm and though they would work the focus, it was too erratic IMO. The only one that would work reliably for me was the pentax 1.7x autofocus adapter.
02-01-2010, 10:18 AM   #11
Loyal Site Supporter
Loyal Site Supporter
imtheguy's Avatar

Join Date: Mar 2009
Location: Virginia Beach
Photos: Gallery | Albums
Posts: 2,950
QuoteOriginally posted by Blue Quote
It actually depends on whether you mean AF or SDM AF. This is where the confusion comes in. There are several good AF options out there for screw drive AF, just not SDM.
If you know of a 1.4 or 2x TC that can use the DA*300 on a K20D in screw drive mode please don't hold me in suspense. I would be happy to try it if it doesnot involve shorting out the SDM contacts per recent thread. Thanks.
02-01-2010, 10:27 AM   #12
Moderator
Site Supporter
Blue's Avatar

Join Date: Jun 2008
Location: Florida Hill Country
Photos: Gallery | Albums
Posts: 17,214
QuoteOriginally posted by imtheguy Quote
If you know of a 1.4 or 2x TC that can use the DA*300 on a K20D in screw drive mode please don't hold me in suspense. I would be happy to try it if it doesnot involve shorting out the SDM contacts per recent thread. Thanks.
No, I was referring to AF on screw drive only lenses such as the FA* 300mm lens. That's one of the reasons people are wanting Pentax to do a Firmware update to allow the ability to turn of SDM in order to use a screw drive TC. The one exception is an early firmware version of the K10d which was pre-SDM.
02-01-2010, 02:06 PM   #13
Loyal Site Supporter
Loyal Site Supporter
AdrianM's Avatar

Join Date: Aug 2008
Location: Ipswich, Queensland, Australia
Photos: Gallery | Albums
Posts: 567
Responding to Lee's question as to which TC is the better with the DA*300, the Kenko or Tamron, I can't give an instant reponse. I only got my Tamron off e-bay in the last week and haven't given it a real test beyond checking that it worked on a couple of lenses and seemed to give good results. However, looking at these two, I would say that they are absolutely identical in manufacture, because the only difference I can find is the external markings for the name. I was amused that one is a 1.5 and the other is a 1.4, so an exercise for this weekend is to measure what they actually do. The photos on my Gallery entries have been using the Kenko 1.5x, and I am very happy with it.
02-01-2010, 02:12 PM   #14
Loyal Site Supporter
Loyal Site Supporter
AdrianM's Avatar

Join Date: Aug 2008
Location: Ipswich, Queensland, Australia
Photos: Gallery | Albums
Posts: 567
... and responding to the other question on screw drive, both the Kenko Pz-AF 1.5x SHQ and the Tamron 1.4X Pz-AF MC4 have scrw drive as well as SDM, and work well on screw drive lenses. The Kenko P-AF 1.5x TELEPLUS MC (available from photo4less) has screw drive only.
02-01-2010, 02:43 PM   #15
Forum Member




Join Date: Jan 2010
Location: Murcia, Spain
Photos: Gallery
Posts: 72
I got the DA*300/4, the Kenko pz-af 1.5x SHQ and a Pentax A 2X-S.

The Kenko doesn't autofocus well with my K10D. SDM works, but only if I prefocus manually close to the object it will lock focus. I have read that with the K20 and with the K7 it works better. The image quality is not bad, but a little soft. Definitly it could be better, but you still gain detail in comparisn to the 300 without TC at 100% view.

The Pentax A 2X-S has great optical quality, clearly better then the Kenko. Excellent details at 100% view. Evidently no autofocus, behaves like an A-lens (anyway, with f=8 AF won't work very well). Focus trap works fine (I assigned AF to the AF-button only; if I want focus trap I push AF and shutter release buttons at a time, and move the focussing ring.

As effective scale increase I have measured 1,52x with the Kenko, and 2,0 with the Pentax.

Best regards - Klaus
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!
1.4x, k-mount, k20d, pentax lens, slr lens, teleconverter
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Anyone used Sigma 70-200 non-HSM AND HSM? which is faster AF? Arpe Pentax SLR Lens Discussion 10 03-24-2010 04:28 PM
Really confused on Teleconverter for Sigma 70-200 f/2.8 HSM YossarianKL Pentax Camera and Field Accessories 6 03-21-2010 04:48 PM
Sigma APO DG MACRO HSM 70-200mm Teleconverter Issue ROBEFFY Pentax SLR Lens Discussion 13 12-20-2009 08:12 PM
Teleconverter for Sigma 70-200 f/2.8 HSM? lunelson Pentax SLR Lens Discussion 7 04-21-2009 02:28 PM
DA*200mm +1.5TC Vs A*300mmF4 danielchtong Pentax SLR Lens Discussion 9 05-24-2008 03:19 AM



All times are GMT -7. The time now is 05:29 PM. | See also: NikonForums.com, CanonForums.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