Back to forums

Esprit 80 with STarzonia Apex 0.65x reducer?

Sky-Watcher Esprit 80ED Reducer Refractors
3 replies•192 views
ScottF avatar
ScottF avatar
I am looking for a wide rig to get below 300mm with decent speed. I am considering the esprit 80 and the Starzonia Apex 0.65x reducer. This would give a 260mm focal length at f.325 which would be ideal. However, I am concerned about the optical quality and whether or. not an APS-C sensor will have good stars in the corners. Starzonias webpage suggests it would be. 
Does anyone have any experience with this combo?
thank you
Scott
Jan Erik Vallestad avatar
Jan Erik Vallestad avatar
I think you're onto something here. I spoke with TS Optics in Germany about this and they claimed that they didn't know of any APO that would be able to correct stars and color at these F-ratios with APS-C.

I was looking for the same thing for my 100ED, but I've tossed the entire idea now. All the images I've seen with these combos are showcasing exactly these issues; stars out of shape and weird colors in the corners especially. I've yet to see any compelling images with the Apex reducer tbh.

Getting a proper scope at that FL wouldn't necessarily cost that much more either. Have a look at the Redcat as an example. It's 50mm shorter and a bit slower, but I reckon it would perform way better across the frame.
Helpful Insightful Respectful Concise Engaging Supportive
Jan Erik Vallestad avatar
Jan Erik Vallestad avatar
ScottF avatar
ScottF avatar
I think you're on to something here. I spoke with TS Optics in Germany about this and they made the claimed that they didn't know of any APO that would be able to correct stars and color at these F-ratios with APS-C.

I was looking for the same thing for my 100ED, but I've tossed the entire idea now. All the images I've seen with these combos are showcasing exactly these issues; stars out of shape and weird colors in the corners especially. I've yet to see any compelling images with the Apex reducer tbh.

Getting a proper scope at that FL wouldn't necessarily cost that much more either. Have a look at the Redcat as an example. It's 50mm shorter and a bit slower, but I reckon it would perform way better across the frame.

Yes, it does seem like a physics-defying proposition. I was looking at the Williams optics Pleiades 68mm, but the discussion on Cloudy Nights didn't sound promising regarding image quality, possibly due to inconsistent back spacing issues.
Well Written