I did the final modification by introducing a short back tube of 2" diameter, it was fitted exactly from the rear lens of the 328 and the 1.25" adapter. So, if that could not eliminate the internal reflection, it is then the intrinsic issue of the 328 optical chain, nothing to do with my modification. Therefore, I call it the final modification.
That tube looked really dark.....
The first test was conducted visually with a Canon 2x extender before a 1.25"diagonal, plus a 20mm eyepiece. The resultant focal length should lie between 600mm to 900mm. That is effective magnification of 30x to 45x.
The moon is very contrasty and sharp! Free of any false color, so I am encouraged.
Here is the first shot:
It seems okay, but the experienced eyes will know there is something wrong. Adding a 5x powermate confirms that it sucks:
The contrast is very low, a signature of internal reflection.
Later on the same night, when Jupiter reached my window, I tested and confirmed that internal reflection was reduced, but it still exists,virtually no detail could be detected.
That modified 328 should be reserved only for imaging of DSOs.