I placed it on the nose piece, however, I only noticed a modest level of correction.
The nose piece is ~27mm. So 124mm total light path.
I'm hoping some sort of extender will help, so I should aim for a 15mm extender to get close to the Baader others have used to great success.
Normally the nose piece is not included in the light path.
This is because if you are using it in a refractor, the nose is in the focuser, and you would not count that because it adds no path at all. The light path is from the rear of the focuser to the top of the eyepiece holder.
If it is an SCT, you use the path length of the visual back because this is usually longer than the nose of the diagonal, and if you counted the nose, you would be counting that light path twice.
Now in the very unusual instance where the visual back will not accommodate the full length of the nose, then you would use the lenght of the nose. Otherwise, you use the visual back and from the front face of the diagonal to the top of the eyepiece holder.
Most 2" diagonals have a light path of 98mm to 104mm, but I have seen one model that had 110mm. This is the longest I have ever seen.
So, the nose is not included in the light path.
Edited by Eddgie, 18 October 2019 - 03:26 PM.