Teleconverters on the Full Frame

bobell69 · 02-29-2016, 12:15 PM

Just wondering if we may see improvement with focus speed and functionality of the Kenko Teleconverters on the Full Frame. Right now I have two with SDM contacts., a Kenko Pz-AF 1.5 Teleplus MC and another no name 2x. The kenko works great on the DA* 50-135, DA 18-135 and my FA 300 F4.5, but it suffers when using the Sigma 70-200 F2.8 HSM OS. Also the 2x converters spends most of the day just searching, and once in awhile it locks in, but rarely.

Adam · 02-29-2016, 12:51 PM

Originally posted by bobell69

Just wondering if we may see improvement with focus speed and functionality of the Kenko Teleconverters on the Full Frame. Right now I have two with SDM contacts., a Kenko Pz-AF 1.5 Teleplus MC and another no name 2x. The kenko works great on the DA* 50-135, DA 18-135 and my FA 300 F4.5, but it suffers when using the Sigma 70-200 F2.8 HSM OS. Also the 2x converters spends most of the day just searching, and once in awhile it locks in, but rarely.

Performance should be very similar, since both cameras have the same AF sensitivity and similar hardware. The K-1 has a few more AF points, which might help with tracking.

narual · 02-29-2016, 07:14 PM

Another nifty thing -- using your kenko 1.5x, your crop sensor lenses will cover the full frame - the 50-135 will have the same field of view as it does on your K-5.

bobell69 · 03-01-2016, 06:03 PM

Originally posted by narual

Another nifty thing -- using your kenko 1.5x, your crop sensor lenses will cover the full frame - the 50-135 will have the same field of view as it does on your K-5.

That's a good point, never thought of that. Will be interesting to try it when I get a K1

**jpzk** · 03-01-2016, 06:44 PM

How about the "old" SMC Pentax-F 1.7x AF Adapter ?
That should be interesting.

i5_david · 03-02-2016, 08:43 AM

I don't want to hijack this thread but i didn't want to open another thread for this. I am on the edge to get myself a converter on eBay or so. Auto focus is not that important to me but IQ should be ok. It seems that kenko produces some

anyways, there are 2x CFE there are KAX I think PAX is in there too and the Internet is not full of any reviews or comparison between them. Someone has insight into these different models? I have an offer for kenko 2X CEF MC 7. Is this one recommendable?
Thanks in advanced friends!

bobell69 · 03-02-2016, 10:47 AM

There are reviews of a number of converters on the Pentax forums lens review pages. You may want to check it out to see if there are any reviews on what you are interested in.

vonBaloney · 03-02-2016, 11:06 AM

Originally posted by bobell69

Just wondering if we may see improvement with focus speed and functionality of the Kenko Teleconverters on the Full Frame. Right now I have two with SDM contacts., a Kenko Pz-AF 1.5 Teleplus MC and another no name 2x. The kenko works great on the DA* 50-135, DA 18-135 and my FA 300 F4.5, but it suffers when using the Sigma 70-200 F2.8 HSM OS. Also the 2x converters spends most of the day just searching, and once in awhile it locks in, but rarely.

Compared to what body? The K-5? Any of the newer bodies should be a big improvement as they are much more sensitive and so should deal with light loss from the TC better.

If you are having problems with the Sigma 2.8 that is probably more to do with firmware as it should be plenty bright enough -- Sigma does have updated firmware for some of their lenses. I needed to get an update to on a 150-400 Sigma model to get it to work with on live view, for instance. (Does it work fine w/o the TC?) Firmware update is free, only the cost to ship there. In the US, they pay for return shipping from their NY facility -- where to send it from Canada I don't know, but worth inquiring to see if there is an update. Also highly possible the OS on the lens makes it not compatible with the TC, at least a non-Sigma one.

infoomatic · 03-02-2016, 11:28 AM

Originally posted by jpzk

How about the "old" SMC Pentax-F 1.7x AF Adapter ?
That should be interesting.

I own one and will report, however, I am probably not the first one here... Looking forward for some tests ;-)

rawr · 03-02-2016, 03:06 PM

Originally posted by i5_david

I am on the edge to get myself a converter on eBay or so. Auto focus is not that important to me but IQ should be ok

FWIW, I have 4 K-mount teleconvertors. In terms of image quality, I'd rank them like this [best to not-so-good]:

- Pentax DA AF REAR CONVERTER 1.4X AW [AF support, WR too, but expensive]
- Kenko Pz-AF 1.5X TELEPLUS SHQ [AF support, SDM usually works]
- Pentax REAR CONVERTER-A 2X-S
- Kenko P-AF 1.4X TELEPLUS MC4 DG

narual · 03-02-2016, 09:33 PM

Is the hs AW tc ff compatible? (I feel like I should have had more acronyms to throw in there...)

**jpzk** · 03-04-2016, 12:56 PM

Originally posted by infoomatic

I own one and will report, however, I am probably not the first one here... Looking forward for some tests ;-)

It will be interesting to find out how this works with the K-1.
This TC was manufactured eons ago, at the time when digital was simply `not there".
Reading the review pages: the description does mention " Image Format Full-frame / 35mm film "

Dr_who · 03-04-2016, 05:50 PM

Originally posted by narual

Another nifty thing -- using your kenko 1.5x, your crop sensor lenses will cover the full frame - the 50-135 will have the same field of view as it does on your K-5.

I tested this today and it's not true. There is visible dark corners that's noticeable. I didn't have a chance to try multiple focal lengths but it's definitely not exactly like on a crop sensor.

narual · 03-04-2016, 07:49 PM

Originally posted by Dr_who

I tested this today and it's not true. There is visible dark corners that's noticeable. I didn't have a chance to try multiple focal lengths but it's definitely not exactly like on a crop sensor.

Hm. Works fine on my ZX-L, for the couple lenses I've tried it with.

Were you using a 1.5x TC? A 1.4x wouldn't cover the full frame.

Dr_who · 03-04-2016, 08:03 PM

Originally posted by narual

Hm. Works fine on my ZX-L, for the couple lenses I've tried it with.

Were you using a 1.5x TC? A 1.4x wouldn't cover the full frame.

Sorry I was indeed using the 1.4 converter. It still is usable but not ideal. Which 1.5x converter do you use, and can it run SDM lenses?

02-29-2016, 12:15 PM	#1
bobell69 Veteran Member Join Date: Sep 2007 Location: Courtenay BC Photos: Gallery \| Albums Posts: 498	Teleconverters on the Full Frame Just wondering if we may see improvement with focus speed and functionality of the Kenko Teleconverters on the Full Frame. Right now I have two with SDM contacts., a Kenko Pz-AF 1.5 Teleplus MC and another no name 2x. The kenko works great on the DA* 50-135, DA 18-135 and my FA 300 F4.5, but it suffers when using the Sigma 70-200 F2.8 HSM OS. Also the 2x converters spends most of the day just searching, and once in awhile it locks in, but rarely.

02-29-2016, 12:51 PM	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,593	Originally posted by bobell69 Just wondering if we may see improvement with focus speed and functionality of the Kenko Teleconverters on the Full Frame. Right now I have two with SDM contacts., a Kenko Pz-AF 1.5 Teleplus MC and another no name 2x. The kenko works great on the DA* 50-135, DA 18-135 and my FA 300 F4.5, but it suffers when using the Sigma 70-200 F2.8 HSM OS. Also the 2x converters spends most of the day just searching, and once in awhile it locks in, but rarely. Performance should be very similar, since both cameras have the same AF sensitivity and similar hardware. The K-1 has a few more AF points, which might help with tracking. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

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02-29-2016, 07:14 PM	#3
narual Veteran Member Join Date: Jun 2013 Location: South Bend (Notre Dame), Indiana Photos: Gallery \| Albums Posts: 1,988	Another nifty thing -- using your kenko 1.5x, your crop sensor lenses will cover the full frame - the 50-135 will have the same field of view as it does on your K-5.

03-01-2016, 06:03 PM	#4
bobell69 Veteran Member Join Date: Sep 2007 Location: Courtenay BC Photos: Gallery \| Albums Posts: 498 Original Poster	Originally posted by narual Another nifty thing -- using your kenko 1.5x, your crop sensor lenses will cover the full frame - the 50-135 will have the same field of view as it does on your K-5. That's a good point, never thought of that. Will be interesting to try it when I get a K1

03-01-2016, 06:44 PM	#5
jpzk Site Supporter Join Date: Jan 2009 Location: Québec Photos: Gallery \| Albums Posts: 8,251	How about the "old" SMC Pentax-F 1.7x AF Adapter ? That should be interesting.

03-02-2016, 08:43 AM	#6
i5_david Veteran Member Join Date: Feb 2016 Posts: 332	I don't want to hijack this thread but i didn't want to open another thread for this. I am on the edge to get myself a converter on eBay or so. Auto focus is not that important to me but IQ should be ok. It seems that kenko produces some anyways, there are 2x CFE there are KAX I think PAX is in there too and the Internet is not full of any reviews or comparison between them. Someone has insight into these different models? I have an offer for kenko 2X CEF MC 7. Is this one recommendable? Thanks in advanced friends!

03-02-2016, 10:47 AM	#7
bobell69 Veteran Member Join Date: Sep 2007 Location: Courtenay BC Photos: Gallery \| Albums Posts: 498 Original Poster	There are reviews of a number of converters on the Pentax forums lens review pages. You may want to check it out to see if there are any reviews on what you are interested in.

03-02-2016, 11:06 AM	#8
vonBaloney Pentaxian Join Date: Oct 2011 Location: Albuquerque, NM Posts: 6,029	Originally posted by bobell69 Just wondering if we may see improvement with focus speed and functionality of the Kenko Teleconverters on the Full Frame. Right now I have two with SDM contacts., a Kenko Pz-AF 1.5 Teleplus MC and another no name 2x. The kenko works great on the DA* 50-135, DA 18-135 and my FA 300 F4.5, but it suffers when using the Sigma 70-200 F2.8 HSM OS. Also the 2x converters spends most of the day just searching, and once in awhile it locks in, but rarely. Compared to what body? The K-5? Any of the newer bodies should be a big improvement as they are much more sensitive and so should deal with light loss from the TC better. If you are having problems with the Sigma 2.8 that is probably more to do with firmware as it should be plenty bright enough -- Sigma does have updated firmware for some of their lenses. I needed to get an update to on a 150-400 Sigma model to get it to work with on live view, for instance. (Does it work fine w/o the TC?) Firmware update is free, only the cost to ship there. In the US, they pay for return shipping from their NY facility -- where to send it from Canada I don't know, but worth inquiring to see if there is an update. Also highly possible the OS on the lens makes it not compatible with the TC, at least a non-Sigma one.

03-02-2016, 11:28 AM	#9
infoomatic Senior Member Join Date: Jan 2009 Location: Austria Photos: Gallery Posts: 255	Originally posted by jpzk How about the "old" SMC Pentax-F 1.7x AF Adapter ? That should be interesting. I own one and will report, however, I am probably not the first one here... Looking forward for some tests ;-)

03-02-2016, 03:06 PM	#10
rawr Veteran Member Join Date: Jun 2009 Posts: 11,913	Originally posted by i5_david I am on the edge to get myself a converter on eBay or so. Auto focus is not that important to me but IQ should be ok FWIW, I have 4 K-mount teleconvertors. In terms of image quality, I'd rank them like this [best to not-so-good]: - Pentax DA AF REAR CONVERTER 1.4X AW [AF support, WR too, but expensive] - Kenko Pz-AF 1.5X TELEPLUS SHQ [AF support, SDM usually works] - Pentax REAR CONVERTER-A 2X-S - Kenko P-AF 1.4X TELEPLUS MC4 DG

03-02-2016, 09:33 PM	#11
narual Veteran Member Join Date: Jun 2013 Location: South Bend (Notre Dame), Indiana Photos: Gallery \| Albums Posts: 1,988	Is the hs AW tc ff compatible? (I feel like I should have had more acronyms to throw in there...)

03-04-2016, 12:56 PM	#12
jpzk Site Supporter Join Date: Jan 2009 Location: Québec Photos: Gallery \| Albums Posts: 8,251	Originally posted by infoomatic I own one and will report, however, I am probably not the first one here... Looking forward for some tests ;-) It will be interesting to find out how this works with the K-1. This TC was manufactured eons ago, at the time when digital was simply `not there". Reading the review pages: the description does mention " Image Format Full-frame / 35mm film "

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03-04-2016, 05:50 PM	#13
Dr_who Veteran Member Join Date: Jun 2009 Location: Edmonton, Alberta, Canada Photos: Gallery \| Albums Posts: 777	Originally posted by narual Another nifty thing -- using your kenko 1.5x, your crop sensor lenses will cover the full frame - the 50-135 will have the same field of view as it does on your K-5. I tested this today and it's not true. There is visible dark corners that's noticeable. I didn't have a chance to try multiple focal lengths but it's definitely not exactly like on a crop sensor.

03-04-2016, 07:49 PM	#14
narual Veteran Member Join Date: Jun 2013 Location: South Bend (Notre Dame), Indiana Photos: Gallery \| Albums Posts: 1,988	Originally posted by Dr_who I tested this today and it's not true. There is visible dark corners that's noticeable. I didn't have a chance to try multiple focal lengths but it's definitely not exactly like on a crop sensor. Hm. Works fine on my ZX-L, for the couple lenses I've tried it with. Were you using a 1.5x TC? A 1.4x wouldn't cover the full frame.

03-04-2016, 08:03 PM	#15
Dr_who Veteran Member Join Date: Jun 2009 Location: Edmonton, Alberta, Canada Photos: Gallery \| Albums Posts: 777	Originally posted by narual Hm. Works fine on my ZX-L, for the couple lenses I've tried it with. Were you using a 1.5x TC? A 1.4x wouldn't cover the full frame. Sorry I was indeed using the 1.4 converter. It still is usable but not ideal. Which 1.5x converter do you use, and can it run SDM lenses?