26mm 2" Wide-View EP question.

[Pinwheel (Doug)]

With my new Bintel 12" Dob, I got a 2" 26mm wide view eyepiece. I think it's just awful, and I am wondering if it's just a cheap piece of junk thrown in with the deal. Has any-one else experienced problems with this particular eyepiece? My other EP's are sharp from center to edge however the 2" is not. Any comment welcome.

[JJDOBBER79 (Jas)]

Hey pinwheel. I just got a meade 12" lightbridge. With it came a meade qx 26mm 2". Rubbish. Maybe it's one of these rebranded or something. It rattles like the glass is going to fall out even though nothing is loose. Quality craftsmanship.

[Pinwheel (Doug)]

Originally Posted by JJDOBBER79

Hey pinwheel. I just got a meade 12" lightbridge. With it came a meade qx 26mm 2". Rubbish. Maybe it's one of these rebranded or something. It rattles like the glass is going to fall out even though nothing is loose. Quality craftsmanship.

You too eh! mine doesn't rattle but the focus falls off 360 deg from center to the edge progressively. Give you vertigo looking in. Real quality...

[barx1963 (Malcolm)]

Doug
The effect you are most likely seeing is coma. Widefield plossl style designs tend to show this aberration more than shorter ones in my experience. The good news is that coma is perfectly natural in any Newtonian design scope and at the f5 ratio of these it is always noticeable with wide views. So there is nothing wrong with either your scope or the eyepieces.
My GSO 12" came with a 32mm and a set of 25mm eps and the coma was very obvious in the 32 but not so in the 25mm 1.25" one that I initially used for most of my observing. If it reallty bothers you and you are wanting an inexpensive suggestion just get a 25mm 1.25" plossl and see how that goes.

Cheers

Malcolm

[Pinwheel (Doug)]

Originally Posted by barx1963

Doug
The effect you are most likely seeing is coma. Widefield plossl style designs tend to show this aberration more than shorter ones in my experience. The good news is that coma is perfectly natural in any Newtonian design scope and at the f5 ratio of these it is always noticeable with wide views. So there is nothing wrong with either your scope or the eyepieces.
My GSO 12" came with a 32mm and a set of 25mm eps and the coma was very obvious in the 32 but not so in the 25mm 1.25" one that I initially used for most of my observing. If it reallty bothers you and you are wanting an inexpensive suggestion just get a 25mm 1.25" plossl and see how that goes. Cheers Malcolm

Hi Malcolm,
I have 40,30,20,15,10,6.5 & 4mm plossl in 1.25mm already. Their sharp as a tack, it's just disappointing the 2" is so bad. I've heard from others these 2" EP's are just nastie.