I currently own a Kowa TSN 824 w/ 20x60 zoom eyeypiece. I also have a Canon A95. I'm getting a machinist to custome build an adapter to mary the two together to complete my digiscoping gear.
The reason I'm getting the adapter done is to save $$ and build it to my provided specification. The adapter will cost me 150$ Cdn to build versus the Kowa model which, IMHO, is way to pricy.
The adapter will screw one to the body of the kowa and extend to the tip of the eyepice with a male 37mm thread ending the piece (it will also have cut outs to let me zoom in/out with the eyepiece. I have purchased an adapter from Lensmate which bayonets on the A95 and goes down to 37mm.
Knowing that my kowa has a focal lenght of 450mm, the eyepiece is a 20x60 zoom and the camera is a 35mm...How do I calculate the focal lenght once all pieced together??