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03-02-2008, 12:42 PM   #1
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M-42 adaptor

Which one of these is the correct one to buy?

Screw Mount M42 to Pentax, Lenses Filters, Cameras Photo items on

03-02-2008, 12:51 PM   #2
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None, if want the most functionality and ease of removal. You will need a Pentax product and this list doesn't include any. They regularly show up on eBay and sell for between $30 and $50. One seller seems to list them often for $42.95 plus shipping............
03-02-2008, 12:52 PM   #3
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I would say none, though the small ones with the removal tools might be able to give you infinity focus (it might, it might not-mine didn't).
03-02-2008, 01:11 PM   #4
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So this isn't the correct one.???
PENTAX K MOUNT TO M42 SCREW MOUNT CONVERTER RING - eBay (item 260215792648 end time Mar-05-08 18:35:38 PST)

03-02-2008, 01:17 PM   #5
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Never mind... I just read this about the adaptor.

This adapter allows a "universal screw mount" type lens (Pentax M42) to be mounted on a Pentax K-mount type body. Although the lens will fit physically, automatic diaphragm (AE metering), or any other functions are not retained using this adapter. In this case you will need to meter in "stop-down mode" since the lens does not have the ability to have its aperture controlled by the camera body.
03-02-2008, 02:34 PM   #6
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It should fit flush with the from face of the mount, otherwise you will not get infinity focus.
It should look something like this item: 280204926906
03-02-2008, 04:58 PM   #7
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QuoteOriginally posted by Fl_Gulfer Quote
I would buy only a Pentax brand adapter. I have had one in the past, and on my KX, it worked just fine. These adapters will give you only stop down metering on a K mount camera, as there is no actuating flange for the aperture pin.
  • If your lens has an auto manual switch, no problems.
  • If your lens has a double f/stop ring - a preset lens - you have no problems.
  • If your lens has neither of the above, but stops down as you move the aperture ring while off the camera, you have no problems.
  • If the lens does not stop down when you move the aperture ring, while it is off the camera, you will only be able to use it wide open, without some means of keeping the pin that actuates the aperture pushed into the lens.

03-02-2008, 06:18 PM   #8
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these adapters are hard to find... but i just picked one up on friday from, better for me cuz i'm canadian

03-02-2008, 06:21 PM   #9
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This one should give you infinity focus. The other ones have a flange at the front that pushes the the lens to far from the sensor plane to allow it to focus to infinity. Take note that I said "should", since there is no way you can verify the depth of the adapter without trying it first.
03-02-2008, 07:58 PM   #10
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Go to the Pentax Web Site and their online store sells the "genuine Pentax" adapter for $30.00 bucks.
03-02-2008, 09:00 PM   #11
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Bought one last week , $30.90 + about $7.00 shipping. Pentax website.

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