Celestron 8se XLT with 6.3 focal reducer = serious coma?

[Pingster]

I did lots of reading and many members say they use the celestron FR6.3 as it gives a wider FOV due to reduced mag and reduce coma. I love wide low mag scanning so bought one

I connected the FR to the OTA visual back, then screwed on my 2in williams optics mirror diaginal then inserted my 31Nagler and then swapped to my 17ethos. In both eyepieces, the eyepieces is 'harder' with eyeplacement than without the FR. Also the coma is much worse! Even for stars directly in the centre of the FOV.

I thought the reducer was supposed to achieve a more pleasing visual experience? For me its made eye placement more difficult, the FOV appears more "sperical" and stars are flaring with coma.

What have i done wrong? Faulty FR?

[John]

I don't think the F/6.3 reducers are designed to be used with 2" eyepieces. When I had C5 and C8 SCT's I used one and it worked well but only with 1.25" eyepieces. Mine was the Celestron Japanese made F/6.3 focal reducer.

[sgazer]

as above, I think it was designed for imaging. It worked extremely well for me with a DSLR. Never tried it with a eyepiece.

[alan potts]

I don't think the F/6.3 reducers are designed to be used with 2" eyepieces. When I had C5 and C8 SCT's I used one and it worked well but only with 1.25" eyepieces. Mine was the Celestron Japanese made F/6.3 focal reducer.

I use my LX with the FR and I do get the slightly more difficult to look through problem, but no coma problems . I know it's a different scope. I also use my FR with 2 inch eyepieces and this will not cause a problem up to 28mm, beyond that expect Vignetting. I do not know how to provide a link to it but there is a good article on Cloudy Nights about such, worth a read!

Alan.

[Pingster]

Thanks for you help. I can confirm ithe FR works great when i switched back to the stock 1.25in diaginal. The views are sharper and the increase of FOV is fantastic. Its a shame, as i hoped it would work with my 2in eyepieces.

Even tho the FR improved my 1.25in views... When i removed the FR, popped back my 2in diaginal and popped in my 31nagler..... The view was much better. The nager gave a much bigger FOV and much sharper than my 1.25in eyepieces (17mm Hyperion, baader Zoom). I have taken my nager for granted over the year, its so much better than all my other eyepieces.

For those using 1.25in diaginal and eyepieces i highly recommend the FR.