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02-06-2008, 09:45 AM   #46
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I have the KEH/Kenko and am very happy with IQ but have had the same focus issues using it on my K100D w/T 18-250. I just bought the only T1.4 on eBay right now ($123) and will see how it compares. A B&H rep told me this am that it is discontinued and wouldn't work anyway. I didn't tell him of these posts.........you just never know.......my FA/DA lenses work well with the Kenko also.

02-06-2008, 09:54 AM   #47
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QuoteOriginally posted by Asahiflex Quote
You can clearly see that the TC screws the bokeh up - as all TC's do.
Yes, I agree...I noticed that right away...I was like, ''Where did it go?''
But the reality is also, that I can't see a reason to use A TC on a short prime. I did it purely for test reasons....
02-06-2008, 10:13 AM   #48
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QuoteOriginally posted by John Kovarik Quote
I have the KEH/Kenko and am very happy with IQ but have had the same focus issues using it on my K100D w/T 18-250. I just bought the only T1.4 on eBay right now ($123) and will see how it compares. A B&H rep told me this am that it is discontinued and wouldn't work anyway. I didn't tell him of these posts.........you just never know.......my FA/DA lenses work well with the Kenko also.
I can say for sure, that my Tamron 1.4 works great with my 18-250
I was just looking in Tamrons web site and they show the TC
http://www.tamron.com/lenses/prod/assets/pdfs/spec_sheets/Slim_Jim_07.pdf
So I doubt they will discontinue it....

On a second note. On may to work this morning, I hooked up the Kenko TC to my 70-300mm lens and at 300mm, it is useless..Hunts and hunts and hunts. I turn the lens one full stop and then it works, but it defeats the TC...
With the Tamron TC 1.4 the lens works great at 300mm with 0 hunting, nada...It focuses and shoots and is sharp...I wonder if it is the difference of that .1 of a difference between the two, or if it is electronics....

I don't have any long fast telephoto lens (F/2.8) to try them on, but i suspect they would do well...But then again the Kenko on my DA*50-135 hunts, no matter what focal length I use...So maybe not...The Tamron does not hunt one bit on my DA*50-135...
02-06-2008, 10:57 AM   #49
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Interesting - in searching the web today for one the only place I didn't look was Tamron. DUH!
All the usual suspects did not have or carry it. Oh well, the one I got is new so we'll see.
(My use of the Kenko on the primes was for testing also.)

02-06-2008, 11:08 AM   #50
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This is the only place I found -- my Tamron TC will arrive tomorrow

Tamron 1.4x AF Teleconverter for Pentax AF: 33392070 Cord Camera
02-06-2008, 11:08 AM   #51
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For some reason I just thought of this again and it wasn't mentioned here yet. The TC's won't transmit the new focal length values to the camera, which isn't a big deal unless your counting on the SR to work 100%. I've seen some threads that have shown that SR still works, but not quite as good as without the TC.
02-06-2008, 12:23 PM   #52
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That's a funny coincidence; I went to Cord on-line and they listed it in stock - I bought my T 18-250 from them. Well at least I didn't pay more on eBay than their price............
02-06-2008, 01:14 PM   #53
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I totally support Javier, the Kenko hunts terribly. I sold the Kenko I had and do not regret it.
I stuck with the Tamron 1.4X, but also have a Pentax 1.5X, (fairly old model) MF, and am very happy with these two.
Personally speaking, I dont recommend the Kenko, but then that is my experience and others may differ.

02-06-2008, 01:17 PM   #54
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QuoteOriginally posted by Bramela Quote
I totally support Javier, the Kenko hunts terribly. I sold the Kenko I had and do not regret it.
I stuck with the Tamron 1.4X, but also have a Pentax 1.5X, (fairly old model) MF, and am very happy with these two.
Personally speaking, I dont recommend the Kenko, but then that is my experience and others may differ.
I wonder if I have a different version. In good light my Kenko doesn't hunt all that much.. especially considering I'm using with a f/5.6 lens, technically the camera shouldn't autofocus at all. Thinking about it, it doesn't hunt anymore then my Sigma 70-200EX paired with the Sigma 2xTC.


John
02-06-2008, 02:30 PM   #55
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I think you hit on the main point - light. Until this thread began I was (and still am) happy enough with the Kenko especially at the KEH price. I took the low-light/high-contrast, indoor v. outdoor differences as the price to be paid. I hope the incoming Tamron 1.4 will shed some more light on it, so to speak............
02-06-2008, 05:53 PM   #56
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QuoteOriginally posted by Bramela Quote
I totally support Javier, the Kenko hunts terribly. I sold the Kenko I had and do not regret it.
I stuck with the Tamron 1.4X, but also have a Pentax 1.5X, (fairly old model) MF, and am very happy with these two.
Personally speaking, I dont recommend the Kenko, but then that is my experience and others may differ.
Thank you Bruce.
I am about ready to pack up the kenko and send it back to B&H.
After spending the day with it, my OWN conclusion is that I can't deal with the hunting and it is no place near the Tamron...Maybe I got a bad one..Just about all of my Pics with the Kenko are throw aways...I am sure with a Tri Pod, I would have good pictures, but I seldom if ever use a tripod...
02-06-2008, 05:54 PM   #57
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QuoteOriginally posted by palmor Quote
I wonder if I have a different version. In good light my Kenko doesn't hunt all that much.. especially considering I'm using with a f/5.6 lens, technically the camera shouldn't autofocus at all. Thinking about it, it doesn't hunt anymore then my Sigma 70-200EX paired with the Sigma 2xTC.


John
John
Consider your self blessed. Your pictures look great, so what ever you have, Keep it!.
02-06-2008, 08:43 PM   #58
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OK
I think I am getting someplace with this Kenko...
First after studying the Histograms, I noticed that the pictures were way underexposed.
(not a problem with the tamy) So, I cranked up the ISO to 800 on the ole K110D and not bad....While it did not cure the hunting, during the day with lots of light, it did auto focus ok...

Here is pic of a sign I took at 300mm with Kenko 1.5tc = 450mm
This was with my Tamron 70-300 cheapo telephoto lens...


Here is another shot at 70mm...


Here is the same basic shot but at 300mm or 450mm.
02-06-2008, 10:07 PM   #59
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Instead of cranking up the ISO did you try just adding a +.5 or +1EV? I find that when using a TC every lens is different.. some I have to dial a +EV some I have to dial a -EV. For example my Sigma with 2xTC I have to dial a -1, my Tokina without a TC I have to dial a +.5 but with the Kenko TC I dial in a 0.

My guess (that is all it is) is that there are slight variations in the actual f stop that the lenses and/or TCs are reporting so when using a TC sometimes you have to dial in a +/- EV
02-07-2008, 07:59 AM   #60
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QuoteOriginally posted by palmor Quote
Instead of cranking up the ISO did you try just adding a +.5 or +1EV? I find that when using a TC every lens is different.. some I have to dial a +EV some I have to dial a -EV. For example my Sigma with 2xTC I have to dial a -1, my Tokina without a TC I have to dial a +.5 but with the Kenko TC I dial in a 0.

My guess (that is all it is) is that there are slight variations in the actual f stop that the lenses and/or TCs are reporting so when using a TC sometimes you have to dial in a +/- EV
I could not agree more. My best friend many times is the ole EV compensation and yes, different lenses often times will use different settings. But in my case, with this lens, they were still underexposing even at max EV.
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