TheSkySearchers

Have had a lot of their threaded adapter rings. Finish is nice and they always threaded with other SV and other brands of rings. There are not many 8mm plossls or orthos to choose from so decided to try one. None available from US stores so ordered direct from China. Took 3 weeks to get here with the lesser shipping option.

On Jupiter against an older Brandon and Celestron plossls it was right in the middle. The Brandon was sharp to the edge as Jupiter slid off the field. The SV went out of focus right at the edge. Sharpness and contrast between light and dark areas was also right in the middle of these two eyepieces.

None of these have much eye relief, but Jupiter was kinda small at 200x in my 8" f5 dob with 1.6x Nikon Barlow, so you could pull back a little and see the whole planet and closest moons. China has made improvements since the Celestron came out in 2012.

Not that one need an excuse to get more EPs, but I was wondering if you already have a couple of 8mm Plossls why get another one?

It may have been better than the Brandon, which despite its price tag is not a superior optic.

Way back in 2006 when the 2nd red spot formed on Jupiter, my Brandon 6mm was the only eyepiece that could see it. Now they have been surpassed by numerous lenses.

Thanks for the review, I was looking for small eyepiece to fill a gap between my 10mm and 6mm Baader Ortho for my binoviewer, Is eye relief too tight for a binoviewer? I can use 6mm BCO, but it has eye relief at the limit

gul1337 wrote: ↑Thu Mar 17, 2022 9:39 pm Thanks for the review, I was looking for small eyepiece to fill a gap between my 10mm and 6mm Baader Ortho for my binoviewer, Is eye relief too tight for a binoviewer? I can use 6mm BCO, but it has eye relief at the limit

Hello gul1337 and welcome to the forums!

gul1337 wrote: ↑Thu Mar 17, 2022 9:39 pm Thanks for the review, I was looking for small eyepiece to fill a gap between my 10mm and 6mm Baader Ortho for my binoviewer, Is eye relief too tight for a binoviewer? I can use 6mm BCO, but it has eye relief at the limit

Eye relief for a 6mm Orthoscopic is typically 0.76 x the focal length so your 6mm should have 4mm eye relief.
Eye relief for an 8mm Plössl is typically 0.50 x the focal length so the 8mm should also have 4mm eye relief.

Design of the eyepiece top can make a difference, though.

Thanks, that would be tight, and with lens being recessed a little, maybe I should think about different design for binoviewer

I have an 8mm HR from TSOptics, 20mm eye relief, 58 degree field that would be much better for bino's. Think saw a Kasai 8MM on Ebay, that WA series that everyone brands as their own, but they don't have a lot of eye relief, but more than orthos.

My guess is that these are made by the same manufacturer.



I have no idea who actually manufacture the Expanse clones though.