While the Tak showed no CA whatsoever on anything whether in or out of focus, the Vixen did pretty well and just showed a very small splash of CA around Vega. No CA around the lunar limb, and the planets at focus and the usual ed doublet CA traces showing in the intra and extra focal image.
The star test on the Tak was pretty much identical inside and outside focus and textbook at focus. The Vixen again does quite nicely but the 1st diffraction ring is a little brighter than ideal and certainly brighter than the Tak's. Tight, uneven brightness, double stars are easier to split with the Tak because of this I think.
Both scopes showed more or less similar detail and contrast on the planets but I was conscious of having to look harder to find it with the Vixen and, as the magnification exceeded 200x the image in the Tak remained sharp and well composed while the Vixen started to lag a little. The Tak handles 200x plus pretty much as well as my (rather good) ED120 does with just slightly dimmer images. 257x and even 300x make you forget sometimes that you just have 3.9" of aperture to play with !
So the Tak FC100DL outperformed the Vixen ED102SS by a small but noticeable margin on these nights at least. The Vixen is still a lovely little refractor IMHO and it's wide field capability combined with pretty decent high power viewing will keep it in my possession
The Tak FC100DL is my 1st Tak and my 1st refractor with a fluorite lens element and I can now understand what the owners of similar Tak models and the Vixen FL's are so enthusiastic about
Edited by John Huntley, 21 June 2016 - 04:10 AM.