What do people think of this eyepiece ?

[drummerp]

Orbinar 2? FMC Super Wide Angle Eyepiece 70° New 26mm on eBay, also, Telescopes, Binoculars Telescopes, Photography (end time 18-May-09 19:24:26 BST)

I'm after a planetary eyepiece what do you think of this one?

Cheers

Neil

[dweller25]

Never heard of Orbinar, however your telescope has a focal length of 650mm so this 26mm eyepiece would give x25 power, even with a good quality x4 barlow lens it will only give x100 power - a bit too low for planetary. You should aim for around x160 = approx 4mm eyepiece (or an 8mm eyepiece with a x2 Barlow)

[drummerp]

I was thinking of using this eyepiece with a 12" dob when I get one for the Mrs. They have 1500mm focal length ??

Cheers

Neil

[drummerp]

I just worked it out, even with a 1500mm focal length scope I would need about a 15mm lens for good planetary viewing.

Thanks for the help

Cheers

Neil

[John]

I find my 9mm and 7mm eyepieces give very nice planetary views with my 12" F/5 dob.

I've got the 32mm version of that eyepiece. It's not a bad eyepiece at all at focal ratio's of F/6 or longer but it's not so satisfactory at F/5. As you have spotted though they are not planetary eyepieces.

John

[albedo0.39]

but it's not so satisfactory at F/5

Hi John. How does this manifest itself ? I'd be interested in yours (and other) views.

Thanks

[drummerp]

Thanks John for your advise.

[M110]

I'd second what's been said - i was using a 6mm for saturn in my 12" at SGL4. Although sometimes seeing isn't good enough to go that high...

regards,

Alex

[The Warthog]

For planetary viewing, you don't really need a wide angle eyepiece, and one of the problems with WA eps is that the cheaper versions tend to work well only in high f/ratio scopes. You would do well to look into an orthoscopic or even a decent plossl for planetary viewing.

[dweller25]

John & WH are spot on.

For a 1200mm Dob something in the range of 7 to 9mm will be great for planetary.

Examples :-

9mm Baader Orthoscopic - £80 gives x133

8mm Televue plossl - £70 gives x150

7mm Baader Orthoscopic - £80 gives x171

All are excellent eyepieces for planetary viewing.

I use all three but do find I have to take my glasses off for a good view.

[drummerp]

So for planetary viewing is it best to have somthing in the range of about x150 or more.?

Cheers

Neil