Is it possible to use my Sunpak MX122 flash with my K100

the lens in question is a Vivitar 75-205 1.38 58mm zoom with close focusing it as baynet fitting same as my new camera, I was wondering what I have to set to be able to use it.

I would like a step by step instruction on how to use my old zoom lens from my film camera on my K100D, I understand that it will be manuel mode only but would like to know what to set up to use it to its full potential, many thanks for your time if you should wish to enlighten me.

Many thanks for your advice, have taken lens to a repairer and await the outcome.

I have just got myself a Pentax K100D and I was hoping to use lens from my old Pentax KM, the standard lens of my KM fits all right, but I have a Vivitar 75-205 zoom that I use on my KM but it will not go on my K100, the problem seems to be a skirt at the camera end of the lens, where as the standard 50mm lens as only a small bit of this, the skirt on the zoom go's around about half way thus preventing the len from going into the mount, would it be possible to cut back this.