New eyepiece advice.

[alfingido]

I am looking for a good 1.25" 15mm eyepiece and quite like the look of ( and price ) of the Skywatcher extraflat series. ( under £50 from FLO)

But, I want to use it in both my ED80 at F7.5 ( no problem here) but also in my Dob at F5.

Skywatcher blurb says it is best suited to F6 and above, will views suffer in the Dob and if so, how? Or can anyone offer a similar alternative for both scopes, about 15mm, about the same price?

Allan

[John]

For £50 it might be difficult to improve on the Extraflat - at F/5 it will work fine it's just that stars in the outer 15%- 20% of your field of view will show some distortion - that bothers some folks more than others.

One alternative would be to look out for a used 14mm Meade 5000 plossl. These are more than your budget new but used you could pick one up for around £50, maybe less. The Tele Vue 15mm Plossl is also excellent although it has a smaller FoV and shorter eye relief - that are going for £61.00 at Telescope House at the moment.

John

[stev74]

Hi Allan,

I agree with John about the 14mm Meade 5000 plossl, I was lucky and managed to pick one up on here in the 'for sale' section. It has a 60 degree FOV, comfortably eye relief and would say less than 10% distortion in my f5 Skywatcher. It has definitely become my favorite EP and I'm happy to recommend them. Also a good place to check for second-hand EP's is : U.K. Astronomy Buy & Sell (you probably already now about this website but just in case!!).

I've bought all my EP's second-hand and when you add up the cost for new I've saved more than half price.

Hope this helps, I'd probably say I'm being a bit conservative with the distortion it could be 5%. I'm just going on memory as it's been a few nights since I've been out due to weather. I can do a proper check the next time I'm out if you still haven't bought an EP.

Cheers

[alfingido]

Thanks for the advice. I've always been happy with Meade, are the 5000 series better than the Extraflat then?

Steve, I like secondhand too, I'll have to keep my eye out for a bargain or two, nothing on Astrobuysell at the moment. Or fleabay!

Allan

[stev74]

I can only advise on the Meade as I've not tried the extraflat the spec for both EP's seems quite similar. Cost wise the meade is about £25 more, you could always check with the guys at FLO. Sure they'd be able to give you the best informed info for both EP's.

Cheers

[steve_bham]

Ive got the extra flat series and they are great EP's. But i have only tried them in my F10 scope so cant comment on lower F ratings. For 50 quid you do get a lot for your money, sharp images good eye relief and quiet smal in size.

I orginally brought the 16mm and liked it that much brought the set. But i do find that one EP that works well for one person might not work for another even in the same scope.