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11-08-2010, 10:54 AM   #1
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Why no teleconverter?

Can anyone tell me why Pentax can't authorize Kenko or Sigma to make an autofocus TC to compliment the DA and DA* lenses? Pentax doesn't appear to see the need for one of their own manufacture. Pentax is a part of HOYA which makes the glass for Kenko. It would seem like a no brainer.

11-08-2010, 11:11 AM   #2
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I guess "they're just not there yet" - although as far as I recall, an old roadmap suggests that one will eventually come out. The current sigma and tamroc tc's do support af, however, so I'd look into that. Also, this should be moved to the lens section.
11-08-2010, 11:18 AM   #3
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I thought there is a Kenko 1.5X AF TC available
11-08-2010, 11:25 AM   #4
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a word of caution regarding teleconverters

Sigma does indeed make a TC for the PK mount which supports autofocus, BUT......
-It does not support SDM lenses, as it is a PKAF mount not PKAF2 mount with the power contacts needed for either the power zoom function or SDM motors
- the design is unique and requires a lens with a resessed rear element, the recess needs to be 35mm in diameter and 12 mm deep. As a result it only works on some long and fast sigma and pentax lenses
If you can live with these limitations it is excellent optically

Tamron did make a TC which supported AF but again no SDM. it was more lens friendly

Pentax does still appear to make limited quantities of the SMC-F 1.7x Auto Focus adaptor, which, while not supporting SDM can give limited range autofocus to aby manual or AF lens faster than F4

11-08-2010, 12:20 PM   #5
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QuoteOriginally posted by Pablom Quote
I thought there is a Kenko 1.5X AF TC available
I think the Kenko 1.5X AF TC is a rebadged Tamron 1.4X AF TC (I'm sure someone will correct me if I'm wrong).

I have a Tamron 1.4X AF TC. Many people post it as "support Pentax SDM."

For the DA* zoom lenses I tested (16-50, 50-135, 60-250), the TC's autofocus works at shorter focal lengths (but then there is no reason to use a TC with the zoom at the short end). When the zoom is at the long end, at shutter release half press, the autofocus keeps hunting back and forth as if it can't decide. If I remove the finger from the shutter release, then quickly half press again, there is a good chance the autofocus will lock.

In other words, it "kind of" works, but is too iffy for action shooting.
11-08-2010, 04:36 PM   #6
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Because Pentax is stupid.
Or maybe just too small to concentrate on more than one thing at a time.
11-08-2010, 04:43 PM   #7
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QuoteOriginally posted by SOldBear Quote
I think the Kenko 1.5X AF TC is a rebadged Tamron 1.4X AF TC (I'm sure someone will correct me if I'm wrong).

I have a Tamron 1.4X AF TC. Many people post it as "support Pentax SDM."

For the DA* zoom lenses I tested (16-50, 50-135, 60-250), the TC's autofocus works at shorter focal lengths (but then there is no reason to use a TC with the zoom at the short end). When the zoom is at the long end, at shutter release half press, the autofocus keeps hunting back and forth as if it can't decide. If I remove the finger from the shutter release, then quickly half press again, there is a good chance the autofocus will lock.

In other words, it "kind of" works, but is too iffy for action shooting.
Don't know if the Kenko is a rebadged Tamron or not, but everything else seems spot on. The Tamron 1.4x works on SDM lenses, but with varying amounts of success. On the zoom lenses, it often requires a second "lock" and wouldn't work well for action shots. I found the 1.4x worked best on the DA*300, both in terms of IQ and AF>
11-08-2010, 05:12 PM   #8
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Umm, I hate to rain on the parade, but Pentax doesn't have to authorize anyone to make K-Mount equipment.
If Kenko ir Sigma wanted to make an AF converter for Pentax, they could do so.
If you want to be PO'd at Pentax for not making a teleconverter, you may have a legitimate beef, but it isn't correct to blame them for what other companies choose to do.

11-08-2010, 05:39 PM   #9
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I have a Kenko 1.5x Teleconverter, the Pz-AF 1.5x Teleplus SHQ, and it works on my Sigma HSM lenses, so I would assume that it would work with SDM lenses? The AF does hunt a bit more, but then again, the AF module has half as much light to use for AF, compared to the original lens without the TC. Screw driven AF is also slower.
This TC also works with my other lenses, i.e. it doesn't have to be matched with lenses with recessed rear elements, like the Sigma TC.

The user "tom1803" occasionally has a few NOS units of these on the marketplace if anyone's interested.

Note that there is another Kenko 1.5x (or was it 1.4x?) TC that lacks the SDM contacts.

Last edited by pop4; 11-08-2010 at 05:55 PM.
11-08-2010, 06:59 PM   #10
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QuoteOriginally posted by pop4 Quote
I have a Kenko 1.5x Teleconverter, the Pz-AF 1.5x Teleplus SHQ, and it works on my Sigma HSM lenses, so I would assume that it would work with SDM lenses? The AF does hunt a bit more, but then again, the AF module has half as much light to use for AF, compared to the original lens without the TC. Screw driven AF is also slower.
This TC also works with my other lenses, i.e. it doesn't have to be matched with lenses with recessed rear elements, like the Sigma TC.

The user "tom1803" occasionally has a few NOS units of these on the marketplace if anyone's interested.

Note that there is another Kenko 1.5x (or was it 1.4x?) TC that lacks the SDM contacts.
What does the SHQ stand for at the end of Pz-AF 1.5 Teleplus SHQ?
11-08-2010, 07:58 PM   #11
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QuoteOriginally posted by SOldBear Quote
I think the Kenko 1.5X AF TC is a rebadged Tamron 1.4X AF TC (I'm sure someone will correct me if I'm wrong).

I have a Tamron 1.4X AF TC. Many people post it as "support Pentax SDM."

For the DA* zoom lenses I tested (16-50, 50-135, 60-250), the TC's autofocus works at shorter focal lengths (but then there is no reason to use a TC with the zoom at the short end). When the zoom is at the long end, at shutter release half press, the autofocus keeps hunting back and forth as if it can't decide. If I remove the finger from the shutter release, then quickly half press again, there is a good chance the autofocus will lock.

In other words, it "kind of" works, but is too iffy for action shooting.
Odd, that is exactly where I use mine. Just last weekend I was using it with my 60-250 at the 200-250 range of the lens. It does hunt more than without it, but I use it for shooting flying waterfowl and that's some pretty quick action.
11-08-2010, 07:59 PM   #12
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QuoteOriginally posted by Wheatfield Quote
Umm, I hate to rain on the parade, but Pentax doesn't have to authorize anyone to make K-Mount equipment.
If Kenko ir Sigma wanted to make an AF converter for Pentax, they could do so.
If you want to be PO'd at Pentax for not making a teleconverter, you may have a legitimate beef, but it isn't correct to blame them for what other companies choose to do.
Lol. Good point. I'm sure Sigma/Tamron/etc didn't wait around for Pentax's approval before launching their various lenses...
11-08-2010, 09:12 PM   #13
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QuoteOriginally posted by fredok1 Quote
What does the SHQ stand for at the end of Pz-AF 1.5 Teleplus SHQ?
Sorry, I've got no idea either. *shrugs*

I did notice that the teleconverter wasn't on the database yet, so I made an entry.
11-09-2010, 04:21 PM   #14
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Super High Quality? We can dream anyway!
11-09-2010, 05:03 PM   #15
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the funny thing is, eventhough Hoya acquired Kenko which produces the PRO series TC which were formerly known as Tamron SP TC's, which they sell for other mounts, they can't even produce one for the K-mount. those Kenko Pro TC's are at par or better than the much loved/well regarded and highly expensive and high quality Canon TC's. you can have the Kenko for the fraction of the Canon TC's cost. these are the Kenko Pro and not the SHQ which is not the same.

as far as the Kenko 1.5 SHQ and and Tamron 1.4 PZ, both TC's support SDM/HSM, although I'm quite suspect if both are the same since both seems to have a different magnification ratio. and it seems that the Kenko 1.5 doesn't look as good in IQ as the Tamron 1.4 PZ. I don't think that the Tamron 1.4 PZ is the same as the Kenko Pro as well.

I'm thinking that the Pro-Optics 1.4x TC, might be a rebadged Tamron 1.4 though.
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