SV130EDT APO vs 7" LX-200 Mak vs 8" LX-90 SCT - Scope Design Comparison Review
By: Vlad Fedosov
I think that if you spend any time reading the equipment
forums on your favorite astro web site you will quickly find that
there are about as many opinions on what the best telescope design is as there
are stars in the sky! Even though I have used just about every scope design out
there when by chance I was in possession of a good sample of some of the
most popular contenders of the "top" scope class out there I was eager to
compare them all on the same night. The scopes that I had for this comparison where
a Maksutov(Mak) 7" LX-200, 8" LX-90 SCT, and an SV130EDT APO refractor. While these are not the
absolute premium offerings for the scope design they represent, these are a
very good sample of scopes that the average guy can afford. Let’s take a look
at what design ended up on top!
The comparison was done from my light-polluted mag 4 backyard. All the scopes were setup outside after sundown and allowed at least an hour to cool down. Since Jupiter and Saturn were still well-positioned in the evening sky I decided to start the shootout with the gas giants. First up was Jupiter. I took looks at the planet with the same Astro-Physics Maxbright diagonal and Badder 24-8 Zoom eyepiece so that I could easily match the magnification and make it as fair of a comparison as possible. After observing the king of the planets in each scope for a few minutes I zeroed in on a magnification around 150x as this is what this night was supporting well. Seeing was not great, but also not bad. The 5" APO showed the Great Red Spot with a much redder hew then ether the Mak or SCT. I also noted that detail is overall more apparent such as small swirl detail. Contrast is also better. The views from the 7” and 8” where very similar with a slight advantage to the 8" SCT.
I also noted that with the Mak you never knew when in focus. SCT was a bit better. Next up was Saturn. The disk does show a bit more shadings and the Cassini division was always better with 5" APO. The two compound scopes unfortunately never reached the same crispness of the APO on ether of the planets. Not sure if they where just not cooled down enough but this is also what I have found in the past. With a very few exceptions I always seem to get better images of the planets and stars with an APO.
I guess that I'm not super surprised that the APO did better on the planets than the SCT but I was surprised by the amount that the view was more contrasty and how much easier it was to pick up the finer detail especially when compared to the highly regarded 7” Mak. Now, in all honesty, I cannot say that I saw more in one scope than the others but I can very comfortably say that the 5" APO showed the detail that there was to be seen much easier. I could see myself missing some of the finer swirl structures in the SCT and the Mak.
Moving onto deep sky objects. Since I was observing under a
light-polluted sky it was a bit hard to do a good comparison but I did get a good feel
for the scopes. Here really the 7” Mak and the 8" SCT were almost
identical in performance with a slightly dimmer image in the APO. The view in the APO
was still more pleasing as far as the rendition of stars and is a lot more
universal in that you can still get a very wide FOV and effortlessly bump up
the magnification for a closer look. If you only had to have one scope and
where interested in seeing the dimmest possible detail then aperture is king
and I would go for the 8” scope. If you want a more universal instrument that
can do wide and deep then the APO is a better choice. If you are into open star
clusters the APO also does very, very well on these. Just about anything else
that can fit in the field of view of the larger scopes will look better though.
Conclusion:In conclusion, if I had to pick one scope out of the bunch it would certainly be the APO. Not really surprising, but I was a bit surprised that the Mak did not put up a better fight! In all honesty after the APO I would choose the 8" SCT simply because it's much lighter physically and cools faster than the Mak.