Vivitar K-mount *almost* compatible?

Archived from groups: rec.photo.digital (More info?)

Hey all. I just got my Pentax *ist-DS and of course tried all my old 35mm
glass on it. I've run across something rather intersting, however. An old 28-105mm
Vivitar lens I've got has a slightly larger ridge on the mount that physically hits
the inside of the *ist-DS. The older P-30T I'd used it with for 15 years has a
slightly different (and more cavernous) shape inside and was never a problem. Has
anyone ever seen this:

http://juneau.me.vt.edu/goodlens.jpg
http://juneau.me.vt.edu/badlens.jpg
http://juneau.me.vt.edu/badlens_top.jpg

It certainly looks like that larger ridge doesn't need to be there. The
smaller ride on the other lens is plent of protection for the aperture lever. I think
a quick removal of that piece and a bit of dremel action may be in order.

I was just curious if anyone else had ever seen something like this.

-Cory

--

*************************************************************************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
*************************************************************************

Archived from groups: rec.photo.digital (More info?)

papenfussDIESPAM@juneauDOTmeDOTvt.edu wrote:

> Hey all. I just got my Pentax *ist-DS and of course tried all my old 35mm
>glass on it. I've run across something rather intersting, however. An old 28-105mm
>Vivitar lens I've got has a slightly larger ridge on the mount that physically hits
>the inside of the *ist-DS. The older P-30T I'd used it with for 15 years has a
>slightly different (and more cavernous) shape inside and was never a problem. Has
>anyone ever seen this:
>
>http://juneau.me.vt.edu/goodlens.jpg
>http://juneau.me.vt.edu/badlens.jpg
>http://juneau.me.vt.edu/badlens_top.jpg
>
> It certainly looks like that larger ridge doesn't need to be there. The
>smaller ride on the other lens is plent of protection for the aperture lever. I think
>a quick removal of that piece and a bit of dremel action may be in order.
>
> I was just curious if anyone else had ever seen something like this.

Yes, this problem is well known with regards to some Vivitar lenses.
Many people have removed or altered this part on Vivitar lenses to get
them to fit on Pentax cameras. I don't know exactly which cameras have
problems with this aperture lever protector, having never owned one -of
the problematic Vivitar lenses myself, but it's been discussed many
times on the Pentax mailing list.

--
Mark Roberts
Photography and writing
www.robertstech.com