Thanks for the help karlssoni, Yes the third port is the photo tube, and that little black knob doesn't really seem to do anything... it screws in and out, but in or out i still can't see anything, i even tried looking down through the eyepiece (which i tested on one of the binocular part so i know it works) AS i unscrewed it and nothing changed.

But your comment made me think it must be something that holds a part in place, and if i loosen it i should be able to adjust something... but i took it out and have been pushing and pulling every little bit and nothing budges.

The thing that bugs me is i just can't see how an image is supposed to come up through that hole? there's no mirror and that black box you can see down in there (with the screws on it) doesn't budge.

And with the binocular parts just don't seem to line up into one picture... they only overlap slightly at the very closest point i can get them and it's virtually impossible to use both eyepieces at the same time without going cross-eyed and getting a headache. I presume from your comment that they should line up and it's not just me?

thanks for your help, any more ideas? i'll contact the distributor.