By: Vlad Fedosov
If you have read any number of my reviews you are likely catching onto the fact that I’m a bit of a sucker for a refractor. I enjoy them for the ultra high end, to the entry level achromat. When I saw a Revelation 80mm “ED APO” for sale that was priced as an achromat I had to jump at the opportunity to check it out. The scope is an F/6 480mm focal length optical tube assembly(OTA) that uses a single speed focuser and finished in a high gloss black.
Having received the scope in early winter of 2018 I was surprised to have a night of clear weather. I anxiously put the OTA on an LXD-75 mount with its built-in foot that is in the shape of a very small Vixen style dovetail. This was my first mistake as the OTA almost slipped out of the saddle! Luckily I was able to catch the OTA before it fell to the ground. I then attached the OTA with a larger vixen dovetail to prevent this issue(this issue was partly because of how the LXD-75 saddle is shaped, but the “dovetail” is so small it does seem dangerous to use it in that way). Finally having it securely mounted my first look through the scope was with the Baader 8-24 Zoom at low power. I was greeted with the familiar razor sharp stars that refractors are known for! I was curious to see what the color correction was on this “ED APO”. I pointed the scope at a random bright star and bumped up the power to the 8mm setting which produces a modest 60x. I, unfortunately, saw an amount of color that I would expect in an achromat. Bumping the power up even more with a 2.25x barlow only exaggerated the issue.
Moving on to the AP use of the scope, I have been thinking of adding a wide field refractor to my main EAA instrument a: 12” LX-850. I attached the Revolution on top of the 12” and matted the scope with an ASI 178MC. Attached is an image that I was able to capture of m45. As you can see the brighter stars show a significant amount of secondary color, and in fact, I feel like this actually detracted from the dim nebulosity being picked up that is around the stars. While I do love the very nice round stars that the scope produces, it does show a very significant amount of chromatic aberration.
Overall I feel that this little refractor would make a great low power Milky Way sweeper but really the performance of it as far as secondary color is not much better than an achromat. If you intend to use the scope at powers higher then 50x, or for astrophotography, I would really recommend you look at something that is a bit better color corrected.