MK-67 focus queston

Hi
I'm hoping someone can answer a question for me, I just acquired a MK-67 150/1500 and when I put a 2" to 1.25" adapter and 1.25" diagonal in the focuser, I had to hold the eyepieces I tried several inches above the diagonal to achieve focus. If I switch to a 2" diagonal can I expect 1.25" eyepieces with an adapter and 2" eyepieces to achieve focus or will an extension tube be necessary?
Thanks, Mark

Not sure about "several inches," but my own MK67 does indeed require a 2-inch-long extension tube (plus 1.25-inch adapter) when using 1.25-inch diagonals. This is a common trait amongst many MK67s, it seems.

On the other hand, my 2-inch diagonal requires no extension -- just an adapter to accomodate 1.25-inch eyepieces.

If you can better estimate the distance from the top of the diagonal's eyepiece collar to the bottom of the eyepiece's lens housing (top of the eyepiece barrel), you'll have a fair idea as to how much extension you'll need to allow a 1.25-inch diagonal (& eyepiece) to reach focus. That's ballpark, anyway.

As a last resort, the primary *might* be "pulled" slightly rearward (just a few millimeters) via the collimation screws on the back plate. This would bring the image plane forward -- nearer to the focuser. HOWEVER, I would strongly advise getting a dealer's help before resorting to that sort of "fix" (shifting the primary rearward). Bit tricky, to say the least.

Best wishes and luck.
-Dan