Yes, essentially. I was looking at my experience using a 100-400 with lots of glass elements, compared to what I've been seeing with the Svbony 102ED with the FR/FF. It seemed to me that the images were brighter, faster, with the scope vice the lens. I also think the refractor design is inherently better for DSO AP in a number of small ways. Enough to ditch the lens and spend money on a refractor that doesn't offer much improvement in resolution etc? I don't know but my gut feeling is, if I'm going to spend more money, I would rather move up than laterally if that makes sense.
The way I was looking at this, was to find a simple way for my nephew (13y/o) to enter DSO AP. The scope I had onhand that would work, was too big for him to handle. So the Svbony doublet made sense to me. Now, if my aim was to improve upon the results from either the Svbony doublet or Canon lens, I think I would be looking at 70-80mm triplets that are designed specifically for DSO AP. As it stands, the Svbony is a great scope and is useful to me as a visual "almost" GnG, so it was a no-brainer to get one. The rotating focuser is something I was skeptical of at first, but it proved itself as very useful and I'm glad to have it now.
As for the rotating focuser, that's actually one of my favorite features on that scope (without even owning one:) ). I am very used to the similar mechanism on my Sigma 150-600. Loosening the tripod collar allows for smooth rotation around the axis. So easy to adjust for the best composition.
Edited by gabebalazs, 08 March 2022 - 05:38 PM.