I believe that it's the V-PEC that's reduced to 2.8arc sec for the AXD2. The V-PEC is recorded @ the manufacturers and stored in non-volatile memory. The AXD is higher as mentioned. Now the older AXD can be further improved with user recorded PEC and therefore can be brought down to 2.8 arc sec too (or lower), however it cannot be stored (nor overwrite) the non-volatile memory. For some reason I thought I read somewhere that the user can store the user recorded PEC on an SD card in the optional Advanced Unit for the original AXD, however for some reason I can't seem to find that documentation -
so, maybe I dreamt that part up .
Edit: I'm not mad :-
"Saving and Reading out PEC Data
The recoded PEC data (PPEC data) on the STAR BOOK TEN can be saved on an SD card (sold separately). The stored data are available with the STAR BOOK TEN.
How to save and read out the PEC data"
Note that the AXD2 also has the newer polar alignment scope.
So far I've been happy sticking to my original AXD, although I nicked the paint a little today!!
Edited by AnakChan, 03 June 2020 - 08:24 AM.