Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
05-02-2012, 08:24 PM   #1
Junior Member




Join Date: Mar 2012
Location: London, Ontario
Posts: 32
Sigma - Pentax Rear Converter-A 1.4X-L compatibility

I have both the Pentax Rear Converter-A 1.4X-L and 2X-L that I purchased for my Pentax 300mm F2.8. Would these 2 converters be compatible with the Sigma (Pentax) APO 150-500mm F5-6.3 DG OS HSM in manual focus on my K5??

Has any one tried this combinations??

Thanks

05-02-2012, 08:51 PM   #2
Pentaxian
rvannatta's Avatar

Join Date: Aug 2007
Location: Apiary, Oregon
Photos: Gallery
Posts: 1,175
QuoteOriginally posted by Bela Quote
I have both the Pentax Rear Converter-A 1.4X-L and 2X-L that I purchased for my Pentax 300mm F2.8. Would these 2 converters be compatible with the Sigma (Pentax) APO 150-500mm F5-6.3 DG OS HSM in manual focus on my K5??

Has any one tried this combinations??

Thanks
I would expect the protruding element to be an issue but don't really know. I have those converters likewise, and have made it a point to
stay with Pentax glass as I have regarded them as 'dedicated' converters. I do know they work grandly with all the classic long pentax
glass--- Both the A* 300 that you have as well as the A*400 f/2.8, 600 f/5.6 and also the FA*300 and the FA*600 and others exotics
that have the filter drawer in the back. I either have owned or do own all of the 5 lenses I specifically mention here, but with a converter like
those you would also have a question of optical compatibility as well as mechanical, and I have no clue.
05-03-2012, 06:44 PM   #3
Pentaxian
littledrawe's Avatar

Join Date: Jan 2010
Location: Red Rock
Photos: Gallery | Albums
Posts: 2,448
QuoteOriginally posted by Bela Quote
I have both the Pentax Rear Converter-A 1.4X-L and 2X-L that I purchased for my Pentax 300mm F2.8. Would these 2 converters be compatible with the Sigma (Pentax) APO 150-500mm F5-6.3 DG OS HSM in manual focus on my K5??
I just posted your question in the lens sample thread for this lens, maybe the actual users of it will see it there and get back to us?
05-03-2012, 06:54 PM   #4
Junior Member




Join Date: Mar 2012
Location: London, Ontario
Posts: 32
Original Poster
Good idea, Thanks!!!

05-03-2012, 08:11 PM   #5
Pentaxian
panoguy's Avatar

Join Date: Sep 2007
Location: Washington, D.C.
Photos: Gallery | Albums
Posts: 3,287
Ciao Bela (just had to write that), here is what I learned from a borrowed 2x-L:

Will it work?
QuoteOriginally posted by panoguy Quote
No. The mount end of the 150-500 lens has two (integral) black plastic "blocks" cutting across the recess to the elements. Here is a photo where you can see what I mean.
See linked photo! It's very narrow at that point, and it isn't far from the lens mount. The "blocks" are thin plastic protrusions that seem to serve no functional purpose except to block access to the depth of the rear elements. My guess is that because the rear elements move forward when you zoom, Sigma wants to prevent users from sticking any longer TCs (like yours) in there and then zooming back to 150mm and knocking their TC front element with the 150-500 rear element.

Last edited by panoguy; 05-03-2012 at 08:19 PM.
05-03-2012, 09:00 PM   #6
Junior Member




Join Date: Mar 2012
Location: London, Ontario
Posts: 32
Original Poster
QuoteOriginally posted by panoguy Quote
Ciao Bela (just had to write that), here is what I learned from a borrowed 2x-L:

Will it work?


See linked photo! It's very narrow at that point, and it isn't far from the lens mount. The "blocks" are thin plastic protrusions that seem to serve no functional purpose except to block access to the depth of the rear elements. My guess is that because the rear elements move forward when you zoom, Sigma wants to prevent users from sticking any longer TCs (like yours) in there and then zooming back to 150mm and knocking their TC front element with the 150-500 rear element.
Panoguy,

Not what I wanted to hear, but thanks. Had I tried it, I could have destroy both the 150-500 & the TC. Thanks for the info!

As for the "Ciao Bella", I am not Italian (Hungarian decent) but I get the play on words . I am a 60+ years, 300 lb, grey haired old fart, Its nice to know I am still beautiful, thanks :ugh:
05-04-2012, 04:03 AM   #7
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,352
Look on the sigma site for compatibility with their own TC. That is a starting point. If it can't work with their TC the Pentax rear converter does not have a chance.

Both TCs protrude into the lens, but the Pentax is actually deeper
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!
converter-a, converter-a 1.4x-l, k-mount, pentax, pentax lens, pentax rear converter-a, sigma, sigma pentax, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Pentax rear converter-a 1.4x-s ultraviolet Pentax SLR Lens Discussion 3 01-16-2012 10:19 PM
Pentax rear converter 1,4x perstromer Pentax Medium Format 4 11-18-2011 12:51 PM
For Sale - Sold: Pentax Rear Converter K (Worldwide) Swift1 Sold Items 2 05-09-2010 10:04 PM



All times are GMT -7. The time now is 10:26 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