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03-08-2008, 05:28 AM   #1
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Da* 200/2.8 & F-af 1.7 Tc............

........anyone know if this combo would work?

03-08-2008, 05:46 AM   #2
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the combo should work just fine.

I use the 1,7x AF TC on several slower lenses and have never had a problem.

You might get some AF indecision because I don;t know how the moving elements in the TC work with the AF in the lens.
03-08-2008, 05:54 AM   #3
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I doubt 1.7X would work well with SDM and it would be interesting if you could try it out!

It sort of loses the whole point of using f1.7 tele which would definitely slow down SDM and jeopardise the image quality of Da* 200

Maybe it is time to pray for new teleconverter from pentax
03-08-2008, 06:15 AM   #4
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You touch on the very point I wondered about. Maybe the Tamron 1.4 would work better. Well I'll find out shortly; my DA* 200 should arrive early next week........

(I think the 'Lens Map' did indicate a new TC sometime.)

Thanks......

03-08-2008, 06:23 AM   #5
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Yeah, it is on the roadmap, in the same line as the DA*300mm, I dont know if that has any relationship to release time but it is on there. No indication of strength but is does say it is for SDM.
03-08-2008, 06:27 AM   #6
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Something I missed with the Da 200, it didn;t occur to me that it was an SDM motor.

There are no power contacts in the a.7x AF TC, so SDM won't work.

As a result put the lens in manual focus, and then what you reall have is the equivellent of an AKA mount lens. this should work.

For anyone who has the Da 200F2.8, does it have mechanical drive for older AF bodies or is it SDM only?
03-09-2008, 09:20 PM   #7
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You will need to set the DA*200 to manual focus, and adjust focus manually on the DA* to roughly the point of focus. This is because the 1.7xAF convertor F can only focus over a small range. Set the body to autofocus which will then drive the AF on the 1.7x with screw drive. Remember that the 1.7x AF was designed to work with Pre F series lenses, and as such pre-dated Powerzoom, HSM etc. I have tried this with DA*16-50 and AF 1.7x adapter.

Teleconvertors with PZ contacts may work, unfortunately, I sold my Kenko PZ converter a few months ago without thinking about HSM, so now I have no way to check.
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