| Author: | | Veteran Member Registered: May, 2010 Posts: 7,403
1 user found this helpful
| | Review Date: April 1, 2017 | Recommended | Price: $25.00
| Rating: 6 |
| Pros: | Optically it is decent | | Cons: | Makes screwdrive lenses MUCH MUCH slower | | Camera Used: K-5II, K-1
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Optically it is nice enough.. I'm not seeing any significant degradation of the IQ using this tele.
However, with screwdrive lenses it is SLOW. How slow? On my K-1 using the HD 55-300mm WR lens, with the Kenko 1.5 pz converter it takes 3 seconds to cycle from infinity to min OR min to infinity. (So, 6 seconds for a round trip) Without the tele? just over 1 second one way (or around 2 - 2.5 round trip).
With the tele it is outrageously slow.
With SDM or DC lenses there isn't that issue since it doesn't use the screwdrive mechanism, so I can still recommend it for those lenses. Or also it can be recommended in the case where you just want to manually focus.
That said, I noticed with the kenko 1.5 and my D-FA 28-105 WR on the K-1, it liked to hesitate focusing on objects indoors. Possibly due to the stop of light lost by using the tele, but I noticed it would focus but the K-1 would get really close to focus, back focus just slightly, front focus just slightly, and cycle incrementally back and forth to smaller degrees until it locked focus.
With just the 28-105mm on the K-1 it is almost insta-lock on focus with the same indoors scenes.
| | | | | | | Junior Member Registered: January, 2016 Posts: 48
3 users found this helpful
| | Review Date: May 16, 2016 | Recommended | Price: $100.00
| Rating: 9 |
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I have only used the Teleconverter on Pentax 55-300mm and Sigma 18-300.
Af works well on both lenses,but its very slow on Pentax 55-300.
This pics is from K3II,Sigma 18-300mm with the Kenko on.
I didnt think it should work with the 18-300mm,but it does work well,and fokus fast to be a very slow lense. 
   | | | | | Veteran Member Registered: June, 2013 Location: Newcastle Posts: 1,954 | | Review Date: December 12, 2015 | Not Recommended | Price: $150.00
| Rating: 5 |
| Pros: | SDM connections | | Cons: | Serious PF @ wide open; IQ only goodish above f8 | | Camera Used: K3
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I have the DG version.
I don't hate this TC, as it does an OK job, but it is not the best I have used. Perhaps I am a little spoilt to have the Pentax 1.4X-L and so expect supreme results. But, I did test this against the supposed Tamron-F equivalent and I can say they are chalk and cheese (perhaps I have a bad copy - perhaps I don't?). The Tamron was far superior in handling CA and PF. The Tamron also provided considerably better sharpness wide open/ near open apertures.
Do I recommend? Barely at the price I paid. Again, perhaps I have a bad copy. For now I do not recommend as the Tamron is similarly priced and far better.
PS I am no longer convinced the Tamron-F 1.4X is the same TC despite looking identical. The differing performance tells me they are not the same TC.
The attached image is the best I could get out of the TC using the F*300
 | | | | | Senior Member Registered: February, 2011 Location: Brno Posts: 295
4 users found this helpful
| | Review Date: June 4, 2014 | Recommended | Price: $120.00
| Rating: 8 |
| Pros: | Cheap TC, AF works | | Cons: | Sigma HSM focusing is bad.. | | Camera Used: K5
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I can compare this TC with Pentax 1.7x AF TC
CD = contrast detect, PD = phase detect
1)
Pentax K5 + 1.5x TC Kenko SHQ + 1.7x AF TC Pentax + Sigma 50-500/4-6.3 @500mm = cca 1275mm
CD AF works, PD has not enough light
2)
Pentax K5 + 1.5x TC Kenko SHQ + Sigma 50-500/4-6.3 @500mm = cca 750mm
Both PD and CD AF works.
3)
Pentax K5 + 1.7x AF TC Pentax + Sigma 50-500/4-6.3 @500mm = cca 850mm
CD AF worsk, PD struggles unless the light is quite strong.
4)
Pentax K5 + 1.7x AF TC Pentax + Sigma 70-200/2.8 HSM II @200mm = cca 340mm
PD AF works, CD AF works.
5)
Pentax K5 + 1.5x TC Kenko + Sigma 70-200/2.8 HSM II @200mm = cca 300mm
PD AF does not end, CD AF about 50%.
6)
Pentax K5 + 1.7x AF TC Pentax + Sigma 17-50/2.8 HSM
PD + CD AF both works.
7)
Pentax K5 + 1.5x TC Kenko + Sigma 17-50/2.8 HSM
PD AF does not end, CD AF about 90%.
8)
Pentax K5 + 1.7x AF TC Pentax + Pentax 18-135 WR
PD + CD AF both works.
9)
Pentax K5 + 1.5x TC Kenko + Pentax 18-135 WR
PD + CD AF both works.
10)
Pentax K5 + 1.7x AF TC Pentax + Sigma 17-70/2.8-4.5
PD + CD AF both works.
11)
Pentax K5 + 1.5x TC Kenko + Sigma 17-70/2.8-4.5
PD works well, CD AF is significantly slower than without TC, but usually works
12)
Pentax K5 + 1.7x AF TC Pentax + Pentax 55-300 @300mm = cca 510mm
PD + CD AF both works. PD needs good light at 300mm.
13)
Pentax K5 + 1.5x TC Kenko + Pentax 55-300 @300mm = cca 450mm
PD + CD AF both works.
Also tested were DA12-24, FA50, FA28-105 - PD + CD AF both works (although TC with lenses like this not worth to be used  Of course 17-50 and 17-70 are not the right hardware for teleconvertor, but I was curous about HSM vs screwdrive.
Summary: Pentax screw-drive lenses works OK with this TC. Sigma screw-drive lenses works OK. Pentax DC lens works OK. Sigma HSM lenses are unreliable/unusable with AF. SDM lenses untested, but might behave like DC Pentax.
Image quality loss is there, but nothing significant. About the same as with Pentax AF TC. Kenko TC does not provide 1.5x times focal length info to camera. With Pentax AF TC the camera asks for the focal length input all the time.
| | | | | | | Forum Member Registered: March, 2011 Location: Ontario Posts: 89
1 user found this helpful
| | Review Date: April 16, 2014 | Recommended | Price: $160.00
| Rating: 8 |
| Pros: | AF, decent IQ | | Cons: | Sloppy mount | | Camera Used: Several
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I bought this after having the Sigma 1.4 AF EX. They were pretty much identical in performance and quality. Both performed well fro shorter lenses (under 300mm). Both had fairly sloppy mounts that allowed the body to twist a bit on them and cause exposure errors. Not a real problem for digital, but not tolerable for transparencies. I eventually got rid of it for the Pentax 1.4x-S which had considerably better image quality a much better mount, but lacked the AF. A more than equitable upgrade in my book.
| | | | | Site Supporter Registered: January, 2009 Location: Springe Posts: 3,693
1 user found this helpful
| | Review Date: March 16, 2014 | Recommended | Price: None indicated
| Rating: 9 |
| Pros: | Good build quality, very little impact on the IQ of the lens, works well with SDM lenses | | Cons: | none | |
I use this TC mainly to extend the reach of my DA 4/60-250.
AT fairly good light there is very little impact on the AF speed and in general very little loss of IQ.
Here is an example shot with this combo
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Main other use is with a manual focus 2.8/90 mm macro lens. The TC allows to keep greater distance when shooting insects. Again without any significant impact on IQ.
Overall great value for money!
| | | | | Senior Member Registered: January, 2010 Location: Murcia, Spain Posts: 100 | | Review Date: January 5, 2014 | Recommended | Price: $100.00
| Rating: 10 |
| Pros: | good optical quality | | Cons: | SDM works somewhot only with the 1,38x version | |
You should be aware that there are two versions of this TC, that have the same name and outer design. The differences:- Scale increase: 1,39x; rear lens diameter: 27mm; rear element doesn't stick out
- Scale increase: 1,53x; rear lens diameter 25mm; the rear element sticks out about 2-3mm.
The first seems to be optically identical to the Tamron pz-af 1.4x TC, the second to a Promaster 1.7x TC.
The first seems to autofocus to some extend with SDM lenses (I haven't tried that version; just telling what I have read), the second doesn't (you have to prefocus very close, and even then it frequently runs away; Catch in focus works).
You can read more about the evidence about the existence of two models here:
http://www.dpreview.com/forums/post/52047400
Cheers - Klaus
| | | | | Site Supporter Registered: September, 2010 Location: MD Posts: 1,029
1 user found this helpful
| | Review Date: January 4, 2014 | Recommended | Price: None indicated
| Rating: 10 |
| Pros: | Provides teleconversion without loss of sharpness and little loss of light | | Cons: | Some loss of contrast | |
I've not had much good experience with a few teleconverters (all 2x ones) I've used previously, but this Kenko came in a grab bag of stuff. Frankly, this is a great teleconverter!
It may be closer to a 1.4x than a 1.5, but the key for me is that it does not lose sharpness. That is, using this teleconverter provides better results than not using it and enlarging the picture. In addition, it has autofocus and auto aperture. It will hunt a bit more to focus. Using Av mode, my K-30 will indicate that I'm losing 1 stop of light with the teleconverter, but I've found that overexposes. On my Tamron 90, I need to set the EV to -1, so I'm gaining that stop back. On my DAL 55-300, I use -.7. On the DA 18-135, -.3. Apparently this tc will also work with SDM lenses, but I don't have one to check it out.
Note that the camera will only register the focal length of the lens and not take into account the 1.5 magnification. This could affect shake reduction, but one is probably most often going to use this w/ a tripod and shake reduction off.
There is a slight loss of contrast, but that is fixable in PP. In the pic, the basketball hoop was about 50 yards away. I'm using the DAL 55-300 at 300mm. The one on the left is with the Kenko. On the right is without but magnified 1.5. Center crops with no other adjustments.
I'm not putting in a price, since I got this in that grab bag of stuff for $20 total. Lucky me!
BTW: After more testing, it sure does seem closer to a 1.4x. Further, this tc looks identical to the Tamron F 1.4 Pz-Af MC4 except for the branding.
| | | | | Site Supporter Registered: April, 2011 Location: Copenhagen Posts: 510
1 user found this helpful
| | Review Date: April 24, 2013 | Recommended | Price: $100.00
| Rating: 9 |
| Pros: | state of the art, sharp, build, convenient | | Cons: | None so far | |
I´m finding this teleconverter very good (reaching towards excellent). And for the used-but-like-new-price of ca100US (including soft bag+caps) and almost no extra gearbag weight, well.. Here is a sample shot taken with K7 and SMC 2.5/135 (manual) wide-open, buildt-in flash, handheld from about two meters distance. (With APS-C crop-factor X1.52) I get a combined tele-lens ‘equal‘ to a FF 4/300mm. With my SMC 2.8/105 I get a 4.3/225mm. Etc.
I added very slight sharpening in PP, (amount:25/radius:1.3/detail:15).
Regards
The whole picture (low-res)
100%crop
 | | | | | Pentaxian Registered: May, 2008 Location: London, UK Posts: 1,697
1 user found this helpful
| | Review Date: May 15, 2011 | Recommended | Price: $120.00
| Rating: 7 |
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Question regarding the photos at the top of the thread - is the top right-hand one actually of the camera-body end of this TC as it shows a group of 6 contacts together, whereas the shot to the left from the lens-end shows a group of 7 contacts together?
My own item has groups of 7 on each side!
As far as performance is concerned, I originally bought it for use with a Sigma 28-200 Aspheric Zoom on an MZ-5N film body, and the performance with that was "OK" IIRC.
However, on a Samsung GX10 (= K10D), with my Pentax 55-300mm zoom "holiday lens", the results were not at all good, and so I never used it much - nor with the fairly early Sigma 70-200 F2.8 that I have - and where the Sigma 1.4x works brilliantly.
Have not tried the Kenko on the K-5 yet - maybe I should 
25 May 2014 update - couple of corrections/additions:
My Kenko-branded version is actually marked "1.4X" not "1.5X" but from what I have just read on dpreview, the two are actually the same animal.
Works fine with the 18-135 Pentax (DC motor) and that combo is what I now take with the K-30 on holiday and general walkabouts. It also seems to work fine with the HSM OS version of the Sigma 150-500 - I only tried that very briefly in poor light in the bedroom at night, but it still autofocused .
| | | | | Site Supporter Registered: October, 2009 Location: Savannah, GA, USA Posts: 57
1 user found this helpful
| | Review Date: April 27, 2011 | Recommended | Price: $170.00
| Rating: 10 |
| Pros: | Allows SDM, clear viewfinder, af good | | Cons: | Slight loss of sharpness | |
I am very happy with this teleconverter. It does what I want it to on my K-5 (mostly with the DA* 200 but also with the 50-135) without the hunting problems I have read about in reviews of other teleconverters. I tried to buy the Tamron-F 1.4X Pz-AF MC4 but it was too pricey (upwards of $300.00) and I looked on this as second best until I actually used it. The Tamron may be better as I've never had one to try but I can't imagine being more pleased than I am with the Kenko.
| | | | | Forum Member Registered: October, 2008 Location: France and Germany Posts: 73 | | Review Date: February 8, 2011 | Recommended | Price: $140.00
| Rating: 8 |
| Pros: | IQ loss is acceptable, works with sdm | | Cons: | focus hunting with some lenses | |
I've been playing with this TC for some time now. I bought it mainly out of curiosity, but find myself using it quite a bit. I use it mainly with my Sigma 105mm macro and am really surprised by the image quality. IQ loss is reasonable (granted, I was prepared for the worst) and is more than outweighted by the additional reach.
I also use it on my DA* 50-135 with mixed results : racked out in good light and contrast conditions, AF is working perfectly, but in many circumstances AF is hunting endlessly or simply unable to lock focus at all. Haven't tried in on newer cameras though (still using my good old K20D)
A friend of mine recently let me use for a week his DA*200 with this TC : works perfectly (nearly no AF hunting) and turns it into a very nice DA*"b" 300/f4
"b" stands here for loss of weathersealing and in this case noticeable but still acceptable IQ loss compared to the real DA* 300.
Overall, a good and inexpensive alternative to longer telephoto glass. Will maybe replace it one day with the long awaited Pentac sdm tc (if it ever comes out ...), since I do a lot of shooting in bad weather conditions.
| | | | | Veteran Member Registered: August, 2009 Location: The British Isles Posts: 2,402 | | Review Date: November 23, 2010 | Recommended | Price: None indicated
| Rating: 9 |
| Pros: | works with SDM | | Cons: | | |
Like any tc, there is some quality degradation. But it works with SDM.
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