Hi Folks. I was looking at some of the Twist-Lock 2" to 1.25" adapters...just as an example the Antares Twist-Lock Adapter 2" - 1.25" among others. Anyways...the description says that it will center your eyepiece or other 1.25" attached equipment and lock it in with a simple twist, since it does not use a thumb screw which would cause the eyepiece to lean to one side. This appears to be the selling point...ease of use and centering the eyepiece.
Thinking deeper as I do and which always gets me in trouble...I said to my self "wait a minute here" ...
These adapters correct half the problem. What I mean by that is, when you install the 2" barrel end into your focuser and or 2" Diagonal, you then have to tighten the adapter with the focuser or diagonal thumb screw (s) or compression ring! Doesn't this push the Twist -Lock adapter slightly to one side?! So now you put your eyepiece in the Twist-Lock adapter which centers the eyepiece but your still half tilted at the barrel end! Am I thinking stupid here? If so it's not the first time nor will it be the last!
I feel a better design would be to have a Twist - Lock at both ends. In other words the 2" barrel end has something like the Hotech Adapter end and the 1.25" end has the Twist-Lock. Of course ideal would be to have 2" Diagonal with both ends like this too. Now your diagonal is centered in the focuser and your eyepiece is centered in the diagonal. I understand about backfocus issues possibly arising, but I am sure this can be minimized somehow as well in the design of the barrel lengths. I think I have too much time on my hands!
Edited by emflocater, 11 January 2017 - 04:29 PM.