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12-08-2011, 07:06 PM   #1
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DA*50-135 + 1.7x tc

Just wondering if anyone have used pentax AF 1.7x tc with DA* zoom or any other zoom.
I just obtained these recently and k5 is asking for the FL for the SR, I'm wondering what should I put for zoom lens since I can only pick 1 FL

12-08-2011, 07:16 PM   #2
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QuoteOriginally posted by Azzy Quote
Just wondering if anyone have used pentax AF 1.7x tc with DA* zoom or any other zoom.
I just obtained these recently and k5 is asking for the FL for the SR, I'm wondering what should I put for zoom lens since I can only pick 1 FL
If you're going to use it primarily at the end of the zoom range, the set it around 230mm (200mm will be your closest choice).

If you're going to zoom a lot, then you'll want to select a lower number, perhaps as low as 85mm, so that the SR system doesn't try to overcompensate for movements at focal lengths lower than the user selected focal length.
12-08-2011, 07:22 PM   #3
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It works extremely well

QuoteOriginally posted by Azzy Quote
Just wondering if anyone have used pentax AF 1.7x tc with DA* zoom or any other zoom.
I just obtained these recently and k5 is asking for the FL for the SR, I'm wondering what should I put for zoom lens since I can only pick 1 FL
I have some test shots with this combination (DA* 50-135 and AFA 1.7x) on my Flickr site - have a look. It is an astoundingly good combination.
12-08-2011, 07:27 PM   #4
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QuoteOriginally posted by Canada_Rockies Quote
I have some test shots with this combination (DA* 50-135 and AFA 1.7x) on my Flickr site - have a look. It is an astoundingly good combination.
Will do, great alternative to 60-250 imo.
Just received these babies tonight along with f*300...I hope the weather is not craptastic this weekend so I can test it

QuoteOriginally posted by dgaies Quote
If you're going to use it primarily at the end of the zoom range, the set it around 230mm (200mm will be your closest choice).

If you're going to zoom a lot, then you'll want to select a lower number, perhaps as low as 85mm, so that the SR system doesn't try to overcompensate for movements at focal lengths lower than the user selected focal length.
Thanks for the advice. Is there any TC that can transmit the fl to the body instead of manually entering it ?

12-09-2011, 02:09 AM   #5
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Even with the TC the IQ is better than for example DA50-200.
12-11-2011, 02:47 PM   #6
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Canada_Rockies, those images are super sharp! Really nice combo with 1.7x
Regarding my prev question, is there any TC that can transmit the fl to the body instead of manually entering it ?
Also how are the AF performance of other TCs with SDM contact ? Are they usable in daylight ? I like pentax's FA 1.7 approach but sometimes it can get annoying due to really short focus throw
12-11-2011, 04:31 PM   #7
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QuoteOriginally posted by Azzy Quote
Canada_Rockies, those images are super sharp! Really nice combo with 1.7x
Regarding my prev question, is there any TC that can transmit the fl to the body instead of manually entering it ?
Also how are the AF performance of other TCs with SDM contact ? Are they usable in daylight ? I like pentax's FA 1.7 approach but sometimes it can get annoying due to really short focus throw
I have never looked for a TC that works with the shake reduction, so I cannot help you there. The more you use the lens with the 1.7x, you'll get used to throwing quick manual focus stabs. Most of the images in my test set were taken with the 50-135 at the infinity stop. The TC handled that fine.
12-11-2011, 04:34 PM   #8
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its not bad for static object near infinity but anything nearer is pretty hard to use since I have no idea where the focus throw of the TC is at. Though I do like the fact all lens including manual become quick shift lens

12-11-2011, 04:39 PM   #9
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QuoteOriginally posted by Azzy Quote
Regarding my prev question, is there any TC that can transmit the fl to the body instead of manually entering it ?
As far as I know, there are no TCs (for Pentax) that will properly transmit the FL of the lens such that you could optimally use the SR system with a zoom.

QuoteOriginally posted by Azzy Quote
Also how are the AF performance of other TCs with SDM contact ? Are they usable in daylight ?
The AF performance of the DA*50-135 with the Tamron 1.4x is fair poor from my experience. It's not much better with the 60-250 and 300 IMO. The TC does allow the use of SMD focusing, but I found that it hunted quite a bit and took a long time to lock unless you were close (in terms of focus). So effectively I used those TCs the same way I would the 1.7x AF-A, but manually focusing close and then letting the AF system do the final "touch-up".
12-11-2011, 04:57 PM   #10
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QuoteOriginally posted by dgaies Quote
As far as I know, there are no TCs (for Pentax) that will properly transmit the FL of the lens such that you could optimally use the SR system with a zoom.



The AF performance of the DA*50-135 with the Tamron 1.4x is fair poor from my experience. It's not much better with the 60-250 and 300 IMO. The TC does allow the use of SMD focusing, but I found that it hunted quite a bit and took a long time to lock unless you were close (in terms of focus). So effectively I used those TCs the same way I would the 1.7x AF-A, but manually focusing close and then letting the AF system do the final "touch-up".
Dan, the Tamron 1.4x PZ TC seems to transmit the FL info as I never get asked for the info when it is attached. (I just treid it to confirm)
I agree that it tends to hunt a lot, especially in lower light,

(to the OP) I only have the 1.4 with PZ contacts, not the 1.7 It is a viable alternative to give a FL of 70-190 @ F4. I think the 60-250 is a far better option though, better AF, better IQ, better range and weather resistant (although heavier).
12-11-2011, 04:59 PM   #11
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There is one bird in flight in that set. It was focused by Mr. Pentax with the 50-135 at infinity. I've also taken some successful sports shots with the combo.
12-11-2011, 05:02 PM   #12
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Thanks for the replies, looks like you both agreed about the af performance of the 1.4tc during low light. How is it during daylight though ?
I won't use this combo at all indoor nor during poor light .

The 60-250 is out of question, way too big and heavy
12-11-2011, 05:13 PM   #13
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QuoteOriginally posted by wizofoz Quote
Dan, the Tamron 1.4x PZ TC seems to transmit the FL info as I never get asked for the info when it is attached. (I just treid it to confirm)
I agree that it tends to hunt a lot, especially in lower light,
You're right, sorry about that. I must have been confusing the fact that the Tamron 1.4x PZ-AF doesn't alter the aperture info the way the 1.7x AF-A does. (I no longer have one, so I was going from memory... bad idea apparently )

More importantly, are you enjoying the 60-250

Edit: Ok, I think I was right the first time. It doesn't ask for the FL because the TC transmits the FL to the body. However, it doesn't apply the multiplier to the FL (much like it doesn't adjust the aperture either). I just looked up some shots I took at 300mm + 1.4x, and the EXIF data show 300mm, not 420mm.

Last edited by dgaies; 12-11-2011 at 05:19 PM.
12-11-2011, 06:39 PM   #14
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lol there's always a compromise I guess, I wish pentax would release WR SDM TC already
12-11-2011, 07:03 PM   #15
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QuoteOriginally posted by dgaies Quote
You're right, sorry about that. I must have been confusing the fact that the Tamron 1.4x PZ-AF doesn't alter the aperture info the way the 1.7x AF-A does. (I no longer have one, so I was going from memory... bad idea apparently )

More importantly, are you enjoying the 60-250

Edit: Ok, I think I was right the first time. It doesn't ask for the FL because the TC transmits the FL to the body. However, it doesn't apply the multiplier to the FL (much like it doesn't adjust the aperture either). I just looked up some shots I took at 300mm + 1.4x, and the EXIF data show 300mm, not 420mm.
You are correct Dan, I'd never noticed the TC does not transmit the FL change, only allows the SDM to work. This is true on both the 50-135, and 60-250 BTW.

The 60-250 is awesome, the 50-135 might still be my favourite zoom of all time, but this baby is catching up fast. The OP is correct about the weight though. according to the PF lens review info it is 1120g vs 65 for the 50-135. The TC does not weigh ~400g, so the 50-135 + TC is a lighter combo.

(you no longer have the 1.4x, cause you sold it to me!!... )
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