Re: [APML] Pentax film plane to mount distance

[DnlMahoney@aol.com]

In a message dated 12/2/01 5:20:40 AM Central Standard Time, mtippett@ticons.com.au writes:


> Hello,
>
> I wonder if there are any Pentax AP people here?
>
> I have got a number of Pentax bits and pieces and I am looking at using
> these for AP.  So the main question that I have is is there any standard
> mount to film plane distance for pentax 35mm equipment?
>
> I have seen conflicting distances of 43 and 55 mm.  (And both my pentax
> bodies have film in them :).  I am not too worried about the absolute
> accuracy of the distance, I will fine tune later.
>
> (This distance is for building a knife edge focuser and adapting a
> webcam for guiding :).
>
> Regards,
>
> Matthew


Matthew,

Here is the information I found. It's taken from a list I found a couple of years ago on someones web page. If you want a copy of the complete list please email me privately.

Pentax K-mount, bayonet = 45.46mm (used by many other mfgrs. also)
Pentax 6x7,bayonet = 84.95mm (74.10?)
Pentax 645,bayonet = 70.87mm
Pentax/Practica,M42x1 thread = 45.46mm

Clear skies,
Dan Mahoney
http://members.aol.com/dnlmahoney