Many thanks to everyone who contributed to this thread, it never ceases to amaze me, the depth of knowlege of people who contribute to Rangefinder Forum. I am, unfortunately not that computer literate, so I apologize for not posting a link to the photo in question. The thing that strikes me about the space program, was that so much of it seemed to be suck it and see. We need a camera, oh just nip down to the local camera shop and buy one, and get the boffins in the back room to screw on a couple of extra large knobs. I realize that was far from the truth, but that`s what it seemed like to me. Thanks again everyone.