I have an iStar 127mm f8 achromat doublet and a SW f9 ED100 and have had them out side by side many times and yes the ED100 is CA free compared to the iStar but there is a whole lot more to these 2 scopes than CA .
#1 , the ED100 and Vixen SP mount can be carried outside and be observing basically straight away as one unit , NOT ! the iStar on CI700 mount , 3 trips minimum ( and 3 after midnight ! ).
#2 , the ED100 is a good luna/planetary scope , the iStar is a GREAT !! luna/planetery scope . It just shows way more detail .
#3 , the ED100 is a good ( ish ) deep sky scope but the iStar is lots better , yes 27mm at this size level is a lot ! .
Overall the iStar shows all objects better if a little CA don't bother you but as #1 above says , be prepared to do a lot more work for the better views , but as you know ' Nothing is free in life '
I use them both about the same amount because of the ease of use the ED100 is used on work nights and nights of average seeing , but on weekends and holiday nights and nights of great seeing its the iStar 127mm that is used and with all the planets basically in the sky at this time , its the iStar that's getting used a lot more at the moment .
Both are good scopes that you are wanting , just be aware that CA can kill it for some people , it don't worry me much so please be aware of it , perhaps join a club and get a few views through scopes of the kind you are wanting before spending money and always wondering ,,,,,, have I made the right choice ? ,, what if ??? etc.
Oh yes , welcome to CN's .
Edited by beanerds, 14 August 2020 - 04:35 AM.