I use a 2" coupling to mount my DSLR on the scope. However, I have an 90 degree mirror angle in the 1.25" size, and would like to use it sometimes for convenience getting my eye on the viewfinder/lcd screen. I was wondering what drawbacks, if any, there were in stepping down the diameter of the light path so close to the sensor might be. Am I going to 'clip' the light path with the smaller diameter and lose light? I've heard most modern scopes are designed for 1.25" so maybe it doesn't matter?