Excellent....many functions and ease of use really make this kind of fun to use.....currently the fires and smoke keep me from using this with my scope but the few times i have been able it has been great .
This is a very good product. However having it and a camera mount + a finder scope on my LX90 12" provided only one screw hole to secure the base to my scope. That made it tricky to install, center properly and tighten down with just enough torque to not strip the threads on the screw/screw hole. The images are bright and clear, and once centered essentially makes the finder obsolete for ***** eye objects which is why I love it. All in all a good bit of kit.
Haven't tried it under the stars yet, but I can already tell that with the larger aperture and multiple reticles to choose from, this is a nice upgrade from the basic Celestron RDF included with my NexStar 6SE. I contacted OPT's customer service prior to purchasing to make sure that it would fit the existing mounting holes on my NexStar, and they (correctly) assured me it would. In my case, I had to purchase longer screws to mount the TPO RDF because the base is thicker than the stock RDF (plus I have the piggyback camera mount which mounts underneath the RDF), but the screws were not hard to find at our local hardware store. I'm sure I'll be much happier with this finder.
I replaced the stock red dot finder on my Celestron Nexstar 8SE and the difference is very noticeable. The coated window is nice and clear, much better light transmission than the stock finder or even a Telrad. I had no problem swapping the standard finder on my 8SE with this one. The build quality is really good, and the alignment stays locked in very well. As is, I really like this finder compared to the stock 8SE finder; I do have some suggestion for improvement for astronomy use though. 1.) The brightness settings could all be dimmed quite a bit; out at a dark site, even the dimmest setting is a bit overpowering. 2.) Change the reticle choices to suite astronomy, it would be much more useful if there was a two-degree circle with a center dot, instead of the circled cross hairs option. 3.) Include a metal stalk, the plastic one included flexes a lot, and does not match the build quality of the finder or dovetail. If you you really want to make this finder great, add a pulsed LED option and 5 min. auto off feature. I'd probably pay $100 for this finder if it included all these improvements!
This finder scope is about the best you can get. Everything about this is perfect. I have a Mead 10 inch Light Bridge. I was able to find Stevens Quintet so easily with this instument. I would recommend this to anyone with a large telescope.
The mounting provided is not interchangeable with standard finders on Celestron SCTs. It is necessary to make an interface to fit the screw spacings on the scope.