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03-25-2009, 11:50 AM   #16
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Pentax AF 1.7X + DA* 50-135 = Winner!

I tested the Pentax AF 1.7X rear converter with the DA* 50-135. I did two tests, one indoors on my bookcase, and the other through a double paned glass patio door on a small lawn ornament about 30cm / 1 ft tall. ISO was set to 1600, aperture to f/2.8. The aperture was reported as f/4.5 in the viewfinder and the EXIF data. The viewfinder also displayed the MF warning and the focus confirmation hexagon. The camera used the screw drive focus. There are no KAF2 contacts on the converter, indicating that the camera determines SDM by the presence of a signal at the power zoom contacts that are now used for SDM AF.

I prefocused by roughly turning the lens focus ring to an estimated distance. The AF 1.7X can only focus within a certain range; it cannot focus all the way from infinity to minimum focus. I set the lens to the infinity stop for the outdoor shot and to 3 meters for the indoor one. When I did not refocus within the range the 1.7X could cover, it ran once in each direction and stopped. I almost expected the camera to cycle through infinity to close focus (converter, not lens) over and over again but it just made the one pass in each direction.

The indoor shot has camera shake blur because I was too lazy to dig out the tripod, but focus was obtained with just two moves totalling about half a second. At ISO 1600, the exposure was reported as 1/2 sec @ f/4.5, which is pretty low light. I suspect part of the focusing problem was my shaky hands.

The outdoor shot was an instantaneous focus - well as fast as screw drive AF can go. There was no hesitation at all. I've included two full images and a crop from the outdoor shot.

All in all, a very usable combination. The Pentax AF 1.7X converter changes my DA* 50-135/2.8 into an 85-229.5/4.76 with more than acceptable image quality.

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03-25-2009, 12:17 PM   #17
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QuoteOriginally posted by Canada_Rockies Quote

The indoor shot has camera shake blur because I was too lazy to dig out the tripod...
Albert,

Even though it's blurry, I can still recognize several of the spines - looks just like my bookshelf!
03-25-2009, 12:22 PM   #18
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Thanks for the test, Canada_Rockies!
I guess the only downside is the weather you're having!
03-25-2009, 12:27 PM   #19
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QuoteOriginally posted by OregonJim Quote
Albert,

Even though it's blurry, I can still recognize several of the spines - looks just like my bookshelf!
I deliberately selected that section to see if anyone noticed. We'll have to compare our libraries!


03-25-2009, 12:29 PM   #20
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QuoteOriginally posted by farfisa Quote
Thanks for the test, Canada_Rockies!
I guess the only downside is the weather you're having!
Pretty much. I took the outdoor shot between flurries. The calendar says Spring, but the weather says Winter. Pretty common up here. I'm ready for something warmer, though.
03-25-2009, 03:05 PM   #21
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QuoteOriginally posted by danielchtong Quote
I believe you are asking the right TC for your DA* lens ( both AF & SDM functions).

I have complied from this and other forums what they know
+++++++++++++++++++++++++++++++++++++++++++++

Tamron 1.4x Pz-AF MC4 AF works. SDM no re Brad (photo.net)

Tamron-F Pz-AF MC4 1.4x both SDM & AF works for DA*300mm re Dave (photo.net)

Tamron-F Pz-AF MC4 1.4x both SDM & AF works for DA*300mm as per Toshi, moderator of Pentaxforums.com.

Tamron-F Pz-AF MC4 1.4x both SDM & AF works only 10% of the time for DA* 50-135mm but hunts a lot re Miserere

Kenko DG Pz-AF 1.5x TELEPLUS MC no AF no SDM on DA*300mm re Dave (photo.net)

Kenko DG Pz-AF 1.5x TELEPLUS MC AF works on older AF lens re Dave (photo.net)

Kenko Pz-AF 1.5X TELEPLUS MC only AF works; SDM no as per jgredline of Pentaxforums.com

Kenko Pz-AF 1.5x TELEPLUS SHQ both AF & SDM works for DA*200mm and all older AF lens re Daniel

Kenko Pz-AF 1.5x TELEPLUS SHQ both AF & SDM works for DA*300mm re Borno (Tom) of Pentaxforums.com .SDM hunts a bit with DA*300mm

++++++++++++++++++++++++++++++++++++++++++++++++++

I am to continue to expand this list when input is provided by other forum members

It is mindboggingly confusing



Daniel
Adam, hello! Can we please have this list on the knowledgebase at the articel sub forum! Daniel, could you add link and submit it to Adam? I think you have made a very good summary. Thanks!

Do you know how they tested if AF (screwdrive) worked on a SDM lens. What I understand a SDM capable camera wont engage screw drive focus on a SDM lens whatever you do?
03-25-2009, 05:27 PM   #22
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QuoteOriginally posted by Canada_Rockies Quote
The indoor shot has camera shake blur because I was too lazy to dig out the tripod, but focus was obtained with just two moves totalling about half a second. At ISO 1600, the exposure was reported as 1/2 sec @ f/4.5, which is pretty low light. I suspect part of the focusing problem was my shaky hands.
Hmm you do not need a tripod to shoot vibration free. Rest your arm on the back of a chair and shoot with 2s delay. That is a foolproof way of shooting vibration free shots at least with the short lens you were testing. For longer lens like 400-500mm that may be different.

Given the blurry image, I would say you did not prove anything at all


Daniel
03-25-2009, 05:36 PM   #23
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QuoteOriginally posted by danielchtong Quote
Hmm you do not need a tripod to shoot vibration free. Rest your arm on the back of a chair and shoot with 2s delay. That is a foolproof way of shooting vibration free shots at least with the short lens you were testing. For longer lens like 400-500mm that may be different.

Given the blurry image, I would say you did not prove anything at all


Daniel
Both shots were hand held. There is no fool proof way of shooting vibration free at 200mm with a 1/2 second shutter speed, which is all I could get indoors even at 1600 ISO. The blur in that image is very obviously camera motion, not out of focus blur. The tests were to see if the Pentax AF 1.7X tele converter would focus properly with the K10D. The results are that it does. Just to settle things down I will repeat the test on the tripod. However I do expect some motion just from the mirror because there is no tripod mount on the DA* 50-135.

03-25-2009, 06:14 PM   #24
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Results of DA* 50-135 + AF 1.7X

Here are the results, using the AF 1.7X, DA* 50-135 on tripod. Full frame, centre 100% crop and top right corner 100% crop. The 1.7X focuses spot on with this lens. I used the on board flash to eliminate the camera shake from the mirror which was still evident despite the heavy tripod due to the 1/2 second shutter speed without flash. Two things are evident
1. This teleconverter works well with the DA* 50-135
2. The DA* 50-135 is sharp corner to corner.

Full Frame, imported to Lightroom and resized only.


Centre 100% crop


Top Right Corner 100% crop
03-25-2009, 11:59 PM   #25
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Tamron-F Pz-AF MC4 1.4x both SDM
Kenko Pz-AF 1.5x TELEPLUS SHQ

seem nice but where to find it?
I could not see them at amazon or adorama.
03-26-2009, 01:55 AM   #26
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QuoteOriginally posted by apemen Quote
Tamron-F Pz-AF MC4 1.4x both SDM
Kenko Pz-AF 1.5x TELEPLUS SHQ

seem nice but where to find it?
I could not see them at amazon or adorama.
Both used to be around a lot before all the talk about SDM motorised lenses. Even though they were out for a long long time, somehow they have the contacts for the former power zooms and thus they can drive the SDM motors. They were all made in Japan as well


Daniel
03-26-2009, 02:26 AM   #27
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I got my 1.5x from KEH at around $60 way back. Seems they are in high demand now and it works best so far with my DA200mm. I do not have DA300mm though as I have A300mmF4
03-26-2009, 03:17 AM   #28
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QuoteOriginally posted by danielchtong Quote
I got my 1.5x from KEH at around $60 way back. Seems they are in high demand now and it works best so far with my DA200mm. I do not have DA300mm though as I have A300mmF4
Thank you danielchtong,

Say, i have found both TCs,
which to choose for DA*200mm?

Tamron-F Pz-AF MC4 1.4x both SDM
or
Kenko Pz-AF 1.5x TELEPLUS SHQ
03-26-2009, 03:57 AM   #29
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QuoteOriginally posted by apemen Quote
Thank you danielchtong,

Say, i have found both TCs,
which to choose for DA*200mm?

Tamron-F Pz-AF MC4 1.4x both SDM
or
Kenko Pz-AF 1.5x TELEPLUS SHQ
There were no direct comparison between the two yet as far as I know. You need only one


Daniel
03-26-2009, 04:01 AM   #30
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QuoteOriginally posted by Douglas_of_Sweden Quote
Do you know how they tested if AF (screwdrive) worked on a SDM lens. What I understand a SDM capable camera wont engage screw drive focus on a SDM lens whatever you do?
In order to see if K10D/K20D can activate the screwdrive instead of the SDM, I would believe I need to cover up the power zoom contacts.

I believe it should work as other older dslr ( DL & K100D) can AF my DA*200mm. I will report later on . Or other forum members can chime in


Daniel
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