Pentax MZ-D

The Pentax MZ-D, also known by its internal code name of MR-52, was a prototype digital single-lens reflex camera from Pentax of Japan. It was announced at photokina in September 2000{{cite web |publisher=DPReview |url= https://www.dpreview.com/articles/8322647280/pentaxdigitalslr |title=Pentax Digital SLR - 6 megapixel |date=2000-09-05 |access-date=2018-03-09}} and was demonstrated to the press at the Photo Marketing Association (PMA) show in January 2001.{{cite web |publisher=DPReview |url=https://www.dpreview.com/articles/2734370763/pentaxdigitalslr |title=Pentax 6mp Digital SLR hands-on |date=2001-02-11 |access-date=2018-03-09}} In October 2001, Pentax cancelled the camera, stating "The cost of manufacturing the prototype SLR 6-megapixel digital camera meant it was not a viable product for our target market"{{cite web |publisher=DPReview |url= http://www.dpreview.com/news/0110/01102401pentaxdslrnomore.asp |title=Pentax cancel 6mp digital SLR |date=2001-10-24 |access-date=2018-03-09}}

The MZ-D was derived from the top-of-the-line Pentax film camera of the time, the MZ-S. To give space for the extra circuitry and battery power required for a digital camera, the MZ-D shape incorporated the size and shape of the MZ-S' optional battery booster and vertical grip. It also shared the Pentax K_AF2 lens mount.

The MZ-D was to use the same 6 megapixel (3072×2048) full 135 film frame sized (24×36 mm) CCD (model FTF3020-C{{cite web |date=2000 |url=http://www.semiconductors.com/pip/FTF3020-C |title=Product information on FTF3020-C, Full Frame CCD Image Sensor |publisher=Philips Semiconductors |access-date=2018-03-09 |url-status=bot: unknown |archiveurl=https://web.archive.org/web/20010727200655/http://www.semiconductors.com/pip/FTF3020-C |archivedate=2001-07-27 }}) from Philips that was used by the Contax N Digital. The lack of success of that camera and the image quality problems it displayed suggest to some that Pentax may have had other reasons than cost to cancel the MZ-D project.

Michael Reichmann of The Luminous Landscape stated, "For whatever their reasons Pentax decided that they couldn't build a camera with this chip, while Contax decided to forge ahead. To save face? Possibly. We'll likely never know for sure"{{cite web |author-last=Reichmann |author-first=Michael |author-link=Michael Reichmann |date=2005 |url=http://www.luminous-landscape.com/reviews/cameras/1n-non.shtml |publisher=Luminous Landscape |title=Contax N Digital: A Non-Review |access-date=2005-11-21 |archive-url=https://web.archive.org/web/20070310230738/http://www.luminous-landscape.com/reviews/cameras/1n-non.shtml |archive-date=2007-03-10 |url-status=dead }}

In 2003, Pentax released a different design 6 MP APS-C sensor size DSLR, the Pentax *istD.