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10-14-2014, 09:36 AM   #1
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Join Date: Apr 2009
Location: Switzerland Vaud
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Helicoidal Extension Tube

Hi all,
I'm new to Pentax 645 world and I have a question
surely a stupid one :-)

I have the 645Z and the new 55mm that comes with it
I bought the Helicoidal Extension Tube on Ebay ,but there is no coupling with the aperture !
is it possible to change the aperture in this lens manually ? or maybe it isn't compatible with the Helicoidal Extension Tube ??
if so, what lenses are ok to use with it ?


10-14-2014, 11:19 AM   #2
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Join Date: Oct 2013
Posts: 24
I guess you need a lens with aperture ring do control it manually.
10-14-2014, 12:06 PM   #3
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Join Date: Mar 2007
Location: Christchurch, New Zealand
Photos: Gallery
Posts: 617
Simple answer. NO. As there is no mechanical aperture coupling, you can not control the aperture of the D FA 55mm lens. You will need any FA or A lens which has an aperture ring to get aperture control, and then you will need to use it in stopped down metering mode.


10-14-2014, 01:52 PM   #4
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Join Date: Apr 2009
Location: Switzerland Vaud
Posts: 3
Original Poster
Thank you seventhdr, that's what I thought !



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