Suggestion Evolution of K-mount Article has Omission

**stevebrot** · 04-09-2019, 10:57 AM - **1 Like**

While the Evolution of The Pentax K-Mount article is an incredible resource, it has deficiency that may not have been obvious when it was first published, but may be now. At issue are lenses such as recent Irix offerings for Pentax and (reportedly) recent Samyang lenses too. These lenses feature the KA2 mount variant (essentially KAF without the AF drive pawl LINK). As such they provide focal length, lens ID information. and perhaps other information through the "data" contact on the mount face. While no current Pentax product uses this mount, it was featured on the ZX-M film camera. Use of the mount by Irix or Samyang (LINK) is something new, and much appreciated.

It would be nice to have KA2 standardized as a mount variant on this site with this mount being called out in reviews when appropriate.

Steve

Adam · 04-09-2019, 12:25 PM

This is a very interesting point. Whether this is a new/different lens mount, or simply a KAF mount without the AF drive shaft, though, is something we should be very careful about. I'd be interested in hearing opinions on this.

**reh321** · 04-09-2019, 12:47 PM

Originally posted by Adam

This is a very interesting point. Whether this is a new/different lens mount, or simply a KAF mount without the AF drive shaft, though, is something we should be very careful about. I'd be interested in hearing opinions on this.

Calling it "KAF" would be misleading.
Calling it "KAF mount without the AF drive shaft" takes lots of words.
Using "KA2" makes as much sense as anything, as long as you explain what it means and how it differs from "KA".

**stevebrot** · 04-09-2019, 02:02 PM

Originally posted by Adam

This is a very interesting point. Whether this is a new/different lens mount, or simply a KAF mount without the AF drive shaft, though, is something we should be very careful about. I'd be interested in hearing opinions on this.

KMP and Wikipedia both list KA2, if that makes any difference. Were it not for current lens support, it would be a small footnote and hardly worth consideration.

Steve

Ole · 04-09-2019, 02:09 PM

Does anyone have a Pentax ZX-M manual. It would be interesting to see what they call the mount.

Does anyone have confirmation that the camera body correctly reads the focal length from such third party lens?

**stevebrot** · 04-09-2019, 02:58 PM - **1 Like**

Originally posted by Ole

Does anyone have a Pentax ZX-M manual. It would be interesting to see what they call the mount.

Does anyone have confirmation that the camera body correctly reads the focal length from such third party lens?

I just looked it up in the manual from the Butkus site..."KA2"

Steve

**reh321** · 04-09-2019, 03:01 PM

Originally posted by Ole

Does anyone have a Pentax ZX-M manual. It would be interesting to see what they call the mount.

I found a manual online.
http://www.cameramanuals.org/pentax_pdf/pentax_zx-m.pdf

On page 46 of the manual {pg 52 of the pdf} sure looks like "KA2" to my elderly eyes.

Ole · 04-10-2019, 02:55 AM

Cool, so KA2 is the official name. I will update the article.

04-09-2019, 10:57 AM - 1 Like	#1
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 34,415	Evolution of K-mount Article has Omission While the Evolution of The Pentax K-Mount article is an incredible resource, it has deficiency that may not have been obvious when it was first published, but may be now. At issue are lenses such as recent Irix offerings for Pentax and (reportedly) recent Samyang lenses too. These lenses feature the KA2 mount variant (essentially KAF without the AF drive pawl LINK). As such they provide focal length, lens ID information. and perhaps other information through the "data" contact on the mount face. While no current Pentax product uses this mount, it was featured on the ZX-M film camera. Use of the mount by Irix or Samyang (LINK) is something new, and much appreciated. It would be nice to have KA2 standardized as a mount variant on this site with this mount being called out in reviews when appropriate. Steve

04-09-2019, 12:25 PM	#2
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 49,083	This is a very interesting point. Whether this is a new/different lens mount, or simply a KAF mount without the AF drive shaft, though, is something we should be very careful about. I'd be interested in hearing opinions on this. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

04-09-2019, 03:01 PM	#7
reh321 retired sw engineer Join Date: Nov 2014 Location: South Bend, IN, USA Photos: Gallery \| Albums Posts: 15,175	Originally posted by Ole Does anyone have a Pentax ZX-M manual. It would be interesting to see what they call the mount. I found a manual online. http://www.cameramanuals.org/pentax_pdf/pentax_zx-m.pdf On page 46 of the manual {pg 52 of the pdf} sure looks like "KA2" to my elderly eyes. Last edited by reh321; 04-09-2019 at 03:07 PM.

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04-09-2019, 12:47 PM	#3
reh321 retired sw engineer Join Date: Nov 2014 Location: South Bend, IN, USA Photos: Gallery \| Albums Posts: 15,175	Originally posted by Adam This is a very interesting point. Whether this is a new/different lens mount, or simply a KAF mount without the AF drive shaft, though, is something we should be very careful about. I'd be interested in hearing opinions on this. Calling it "KAF" would be misleading. Calling it "KAF mount without the AF drive shaft" takes lots of words. Using "KA2" makes as much sense as anything, as long as you explain what it means and how it differs from "KA".

04-09-2019, 02:02 PM	#4
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 34,415 Original Poster	Originally posted by Adam This is a very interesting point. Whether this is a new/different lens mount, or simply a KAF mount without the AF drive shaft, though, is something we should be very careful about. I'd be interested in hearing opinions on this. KMP and Wikipedia both list KA2, if that makes any difference. Were it not for current lens support, it would be a small footnote and hardly worth consideration. Steve

04-09-2019, 02:09 PM	#5
Ole Administrator Join Date: Sep 2006 Location: Copenhagen, Denmark Photos: Gallery \| Albums Posts: 4,154	Does anyone have a Pentax ZX-M manual. It would be interesting to see what they call the mount. Does anyone have confirmation that the camera body correctly reads the focal length from such third party lens?

04-09-2019, 02:58 PM - 1 Like	#6
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 34,415 Original Poster	Originally posted by Ole Does anyone have a Pentax ZX-M manual. It would be interesting to see what they call the mount. Does anyone have confirmation that the camera body correctly reads the focal length from such third party lens? I just looked it up in the manual from the Butkus site..."KA2" Steve

04-10-2019, 02:55 AM	#8
Ole Administrator Join Date: Sep 2006 Location: Copenhagen, Denmark Photos: Gallery \| Albums Posts: 4,154	Cool, so KA2 is the official name. I will update the article.

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