Replace eyepieces or pad out range?

[Calculon]

Hello all,

I have recently acquired a 10" F/5 Dob and am curious about eyepieces. The scope (Revelation/GSO) came with a 1.25" 9mm Plossl and a 2" 'Superview' 30mm Plossl. Perhaps I am jumping the gun, but I also ordered a 6mm ortho to serve as a highish power (primarily planetary) option - couldn't help myself what with Jupiter being in opposition next month! I am wondering if I should pad out my selection of focal lengths before considering replacing the standard 9mm and 30mm? My current thinking is that whilst they're not perfect they will serve adequately until I have a good selection of eyepieces. I'm in no rush of course, just wanted to pick some brains.

Any advice appreciated!

[John]

Hi,

As I see it, the only real "gap" you have is around 15mm. If you filled that with, say, a 15mm plossl you would have:

40x, 80x, 133x and 200x.

Thats quite a good range to get you up and running with the scope and the eyepieces are plossls (plus the Superview) so better than some that come supplied with scopes.

You could then get a good feel for the scope while you save up for the next step up the eyepiece ladder (if you feel you need to take it) which would be to eyepieces that cost around £50 each and upwards.

You can get a decent 15mm plossl for around £20.

[Calculon]

What brands would you recommend at the low budget end? I've read that the GSOs/Revelations are fairly decent there. Should say I'm not opposed to paying a little more if I'm likely to keep hold of the eyepiece for a significant period of time.

[John]

The GSO / Revelation plossls are good as are the Vixen NPL plossls which sell for around £30 new. A used Tele Vue plossl can be had for £45 if you keep your eye out for them which would be a real "keeper" eyepiece, unless you develop a taste for wide fields of view.

[phoobar]

Hi Calculon If the 9mm you have is the gso/revelation I would keep it as I have the same and have been very impressed with it for the money, excellent views of jupiter, great red spot clearly seen in colour when viewing is good . It works fantastic in my barlow too giving the equivalent of a 4.5mm.

I would look at a 1.25" 2x revelation/gso barlow on astroboot or similar, this will give each ep 2x focal lengths, although you  wont be able to use it with your 30mm. This will also help with eye relief as the smaller focal lengths will require you to have your eye very close to the lens so barlowing longer focal lengths to shorter will maintain original eye relief .

A 15mm would be good as barlowed would give the equivalent of a 7.5mm ep.

I would stick with the revelation/gso range of ep's unless you want to spend £50+ per ep for other makes. Explore scientific Maxvision 68 fov are excellent value for money and relatively inexpensive.

Theres a thread in beginers equipment "should I buy a barlow" (or something like that) have a quick read through that.

Revelation/Gso Plossls http://www.telescopehouse.com/acatalog/Online_Catalogue_Revelation_Eyepieces_34.html

Explore Scientific Maxvision http://www.astroshop.eu/m,Explore-Scientific?q=maxvision

[phoobar]

Here is the barlow thread http://stargazerslounge.com/topic/235302-is-it-worth-buying-a-x2-barlow-definitely/  

Purists probably would advise to drop the barlow and get individual ep's but many people swear by them

[ronin]

The 2 plossl's (assuming they are Plossl's) will be pretty good, the ojnly reason to "replace" the 30mm is that being a 2" you have to change the adaptor at the same time. Is this the reason behind replacing the 30mm ?

If yes then I can understand it, a selection of 1.25" eyepiece is a bit easier to get along with.

Presuming that is the reason I will say that another 30mm plossl would be useful but in 1.25" format.

In the plossl selection the GSO/Revelations are good and as John says so are the Vixen NPL plossls, about £35 each.

The TV plossl's are good however even if one comes up used you have to be the person that gets it. They do not generally hang around long.

Next ones that people go for are the BST Starguiders at £49 and the Celestron X-Cel's at £59. I think 6 in each set (ignoring the shortest one in each, just too short) so it is not uncommon for a person to collect the 6. Either set would be something to collect and that would last for years with little need to upgrade. I have the BST's, actually one and a half set of BST's. The half set being for use at public shows with a small goto.

[jonathan]

I second the X-Cels, they are solid performers in an average scope and will do well in more expensive scopes too.  A lot of the time an eyepiece's performance depends a lot on the seeing conditions - I splashed out on a Pentax 3.5mm for use with my refractor, it gave superb views of Jupiter on the first time out with it (though a slight heat haze made the view a little wibbly), next time out it was half as good due to conditions, maybe there was some thin high cloud and wind that I couldn't otherwise see; in these cases the best view might be through that X-Cel 10mm.

[Calculon]

Thanks for all the input. To be clear I'm not replacing anything just yet, just wanted some confirmation that the best route is likely getting a good selection going before doing anything else.

Lovely clear night so just been out observing, Jupiter really did look excellent through the 9mm!