Advice on next eye piece - 6mm or 8mm for f5 dob.

[andyb505]

Hi all,

I am looking to buy my next eye piece. I am happy with the wider eye pieces that I already have (see sig below) but I would like to get a better short one than the 10mm that came with the scope.

I am considering either a 6mm (possibly TMB planetary, William Optics or Baader classic ortho?) or an 8mm (possibly BST or Vixen?). I primarily want one for planetary viewing (Saturn, Jupiter etc.)

Given that I have an f5 scope what would others recommend?

I know I have a simple cheap scope at the moment but I am hoping to upgrade to maybe a Skywatcher Skyliner Dob at some point in the near future so I don't mind spending a bit on the eye pieces as I will probably keep them after the scope upgrade.

Grateful for any advice.

Andrew

[triton1]

You can,t go wrong with the 8mm Bst I still have mine works fine at f5 good contrast aswell.

[ronin]

I suspect either will be useable, the 6mm may be preferred for planets (WO 6mm planetary?), Staurn is about as high as it gets in about a month so that may be worth considering as you will get about 108x.

Almost equally the 8mm (BST?) will be a good all round eyepiece.

[Paul73]

It looks like you have already done a load of research.

I would go for the BST as a good a good all round eyepiece. It is comfortable to use, has a nice wide field of vision and performs well at f5. You will have to go for the Vixen SLV at double the price to get a significant improvement over the BST. However, you only get 50° vs 68° so you need to enjoy nudging.

The BCO is another 50° degree wonder with really splendid image quality, but very short eye relef. Personaly, I find this too uncomfortable for long sessions.

Hope that this helps.

Paul

[damnut]

All agreed above, but 8mm is very close to your 10mm. Have you thought about a 2* barlow?? as that would take your es16mm in effect  to the mag for an 8mm. Else I would go direct for BST 5mm or TMB 6mm.

[andyb505]

Thanks for the feedback so far.

Couple of point. I already have a 2x Barlow so I guess the 6mm might be better, but I wonder if it might be a bit much for the scope?

I also like a bit more eye relief (old eyes!) so anything with very short eye relief will probably not work for me.

Andrew.

[Dom1961]

I got the 8mm bst the other day, used it on Saturday even though there was a lot of high cloud but still got a clearer image than I got from the stock 10 mm on a clear night

[Dom1961]

And the bsts are really comfortable to use and the eye relief is great!

[Gentle]

The 8mm BST is the one I went for as my first EP upgrade and I am very happy with it. I find that I use it far more often than the 5mm BST which needs much better seeing conditions to perform well. 

Frank