Sorry for another 'VS' thread but specifically talking I haven't found a direct comparison thread with the similar title (I'm a bad searcher BTW.).
First of the two is a very popular ED FPL-53 doublet family while the second AFAIK is FK-61 equivalent of FPL51.
Both are out of my budget but I can start scrambling up some money to reach out for at least the Stellarvue 110 F7 (in the European TS version: https://www.teleskop...-Focuser.html).
Although I've read some reviews and know of noticeable CA in the 110 F7 My question is: How much of that CA is actually present and how badly will it affect the contrast and sharpness of the image compared to a comparatively "flawless" SW 120/100ED?
I'll be using the scope exclusively for visual and almost exclusively on planets. I need a narrow frac tube in the 4" to 5" range set at an angle for my tight balcony framing when the planets approach South (otherwise they are too low at our location while still raising and my larger aperture scope will not fit the framing).
Would it be wise to get instead of TS 110 F7 the TS 102 F7 FPL-53 version (https://www.teleskop...-Objective.html) ? They are the same price.
Otherwise I could still scramble up (with really hard effort) some more $$$ to reach out for Skywatcher 100 F9 ED.
Unfortunately I doubt I would be able to make one more step up to get the Skywatcher 120 F9 ED.
In terms of the aperture: the FK-61 110 mm scope is right in the middle of other two aperture options, 102 mm and 120 mm.
My initial logic is the following: since I cannot afford the 120 FPL-53 ED scope I first step down in aperture for a lower grade FK-61 glass in very close 110 mm aperture. That is, while downgrading I first think in terms of aperture (and overall brightness of the image).
Does my logic look flawed? - I can admit I feel it is in a way. Maybe it would be wiser to go down 20 mm in size and keep the FPL-53 glass in the equation? In which case I already lose 20 mm of the aperture but retain the better glass in the light path.