Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
03-20-2017, 03:55 PM   #1
Junior Member




Join Date: Feb 2017
Posts: 26
Quest to find a Teleconverter

So... Is there a Teleconverter out there...
With a less-than-10-years-old design
That doesn't cost a Bazillion $
That offers more than 1.4x focal length factor
And with decent IQ?

I'm asking too much I know...

Thanks

03-20-2017, 03:58 PM   #2
Pentaxian
bertwert's Avatar

Join Date: Jun 2015
Location: Golden, BC
Photos: Albums
Posts: 5,169
No.

Closest would be the FA 1.7x, or Sigma 2x.

The current best bet for teleconverters is the Pentax HD 1.4x
03-20-2017, 04:06 PM   #3
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 41,399
Teleconverters these days have to be exceptionally good optically, and are thus expensive, because really good consumer telephoto lenses already exist at affordable prices (like the DA 55-300mm for example). So, the target audience is users of premium lenses that want more reach.

Sigma has some converters that as still good but not expensive, if you can find one.

Adam
PentaxForums.com Webmaster (Site Usage Guide | Site Help | My Photography)



PentaxForums.com's high server and development costs are user-supported. You can help cover those costs by donating. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

03-20-2017, 04:32 PM   #4
Site Supporter




Join Date: Jan 2011
Posts: 2,278
The problem with Sigma Tcs (at least the AF ones) is that they are only compatible with a few Sigma lenses.
After trying multiple TCs I can tell that 2x are not as good as 1.4x, 1.5x or 1.7x ones.

03-20-2017, 04:42 PM   #5
Site Supporter
cali92rs's Avatar

Join Date: May 2011
Location: Long Beach, CA
Posts: 3,262
QuoteOriginally posted by Tigs Quote
So... Is there a Teleconverter out there...
With a less-than-10-years-old design
That doesn't cost a Bazillion $
That offers more than 1.4x focal length factor
And with decent IQ?

I'm asking too much I know...

Thanks
Not in Pentax-land. You are stuck with a 1.4X if you want a newer design.
Nikon has a newer one that is great optically and has 2.0X. It is pricey, but not quite a bazillion dollars (it goes for $500).
03-20-2017, 05:35 PM   #6
Pentaxian




Join Date: Jan 2015
Location: mid nth coast,nsw
Photos: Gallery
Posts: 1,652
QuoteOriginally posted by sergysergy Quote
The problem with Sigma Tcs (at least the AF ones) is that they are only compatible with a few Sigma lenses.
Yes, there is one that's only compatible with high end glass, but others that work with all lenses.




QuoteOriginally posted by Tigs Quote
That offers more than 1.4x focal length factorAnd with decent IQ?
Yes, theres the Kenko/Vivitar Tamron....some versions are 1.5x....theres 2 separate entries in the 3td party lens review section


Pentax has 2 very fine TCs....4.7x and 5.6x(Q!) just attach a lens with adapter but they are not AF!
03-20-2017, 06:01 PM   #7
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 24,363
There's along and involved discussion here, still waiting for someone who's found the perfect converter.
Any Pentax compatible Teleconverters out there? - PentaxForums.com
03-21-2017, 03:48 AM   #8
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,346
QuoteOriginally posted by Tigs Quote
So... Is there a Teleconverter out there...
With a less-than-10-years-old design
That doesn't cost a Bazillion $
That offers more than 1.4x focal length factor
And with decent IQ?

I'm asking too much I know...

Thanks
QuoteOriginally posted by bertwert Quote
No.

Closest would be the FA 1.7x, or Sigma 2x.

The current best bet for teleconverters is the Pentax HD 1.4x
The OP needs to tell us more, especially about the lenses he is using,

The sigma TCs need a 35 mm diameter 12 mm deep recess in the rear of the lens it is going on, in order to work due to a protruding front element in the TC. In fact, for those who want to stack TCs , you can't stack two sigma 1.4x together, and a 1.4x must attach to the rear of the 2x not the other way around, to fit together, again due to the protruding front element.

The Pentax SMC F 1.7x autofocus adaptor is good, but note that it only offers limited range autofocus, and should be used with a lens F4 or faster to guarantee reliable autofocus, although I good light newer bodies can work with slightly slower lenses (up to F5.6)


For me, unless you have an exceptional short lens a TC is not worth it,,they are good when used as n high quality telephoto lenses

03-21-2017, 04:56 AM   #9
Pentaxian
bdery's Avatar

Join Date: Mar 2008
Location: Quebec city, Canada
Photos: Gallery
Posts: 5,695
QuoteOriginally posted by Tigs Quote
That offers more than 1.4x focal length factor
Get the Pentax HD DA 1.4x converter and crop, you'll get better results than with a 2x TC.
03-21-2017, 05:54 AM   #10
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 24,363
QuoteOriginally posted by bdery Quote
Get the Pentax HD DA 1.4x converter and crop, you'll get better results than with a 2x TC.
Pentax says the 1.4 is developed for a 3% loss of resolution, but it's a 40% gain, so the increase of resolution on the subject should be 37%, unless your subject fils the frame and you can't crop.

Sometimes it get used on my K-1, and it barely vignettes at all, other times it does need cropping, but I don't think it's ever needs to be cropped down to APS-c size.
03-21-2017, 06:31 AM   #11
Senior Member




Join Date: Nov 2015
Location: Sydney
Posts: 178
QuoteOriginally posted by bdery Quote
Get the Pentax HD DA 1.4x converter and crop, you'll get better results than with a 2x TC.
The Pentax HD DA 1.4 TC is up there with the best but it's in the bazillion $ category.
03-21-2017, 09:19 AM   #12
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 24,363
Today with the K-3 and Tamron SP AF 300 2.8 and F 1.7x AF adapter
100 ISO, ƒ5.6, AV
With this combo I rarely notice I'm even shooting in AF.

I'm posting these only in the threads where folks have shown interest. The common folks have seen enough otter images. It's not like that are squirrels or something.









03-21-2017, 09:39 AM - 1 Like   #13
Pentaxian
bdery's Avatar

Join Date: Mar 2008
Location: Quebec city, Canada
Photos: Gallery
Posts: 5,695
QuoteOriginally posted by Theov39 Quote
The Pentax HD DA 1.4 TC is up there with the best but it's in the bazillion $ category.
Price, and our ability to pay, is of course relative. However the HD TC is less expensive than any tele prime lens. You can't have superb IQ for cheap.
03-21-2017, 09:44 AM   #14
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 24,363
QuoteOriginally posted by bdery Quote
Price, and our ability to pay, is of course relative. However the HD TC is less expensive than any tele prime lens. You can't have superb IQ for cheap.
Exactly, what is the point of getting a cheap TC? Many of them give you the same IQ only blown up larger. And even good ones only work on DA*s and other lenses that have resolution to spare. A lens that doesn't even excel without a TC is just going to be worse with one.

The Tamron above is rated a 10 for sharpness on the forum. On my old Vivitar 135 the TC just enlarges the purple fringing.

Last edited by normhead; 03-21-2017 at 09:55 AM.
03-21-2017, 10:09 AM   #15
Veteran Member
wissink's Avatar

Join Date: May 2014
Location: S-ON
Photos: Gallery
Posts: 602
Really enjoyed those images Normhead. Thanks for sharing them. What a neat moment when you encounter wild life like that. Just started watching a show called "Alone," last night. its a survival show were ten guys are completely alone on northern Vancouver island surrounded by bears, cougars, wolves, jungle and salt water. Its amazing what nature will do to a man's preconceptions and his psyche.
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, teleconverter
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Sports 2016 Yukon Quest skierd Post Your Photos! 3 02-08-2016 12:41 PM
Abstract I had unexpected quest today :) manntax Post Your Photos! 2 10-03-2013 10:18 AM
The Qingfisher Quest baro-nite Pentax Q 30 02-19-2013 01:03 PM
Fast zoom quest Giklab Troubleshooting and Beginner Help 9 01-26-2012 02:56 PM
Newbie lens quest... DrDespair Troubleshooting and Beginner Help 17 06-04-2010 06:31 PM



All times are GMT -7. The time now is 11:43 AM. | 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