another eyepiece question

[nicks90]

hi folks, sorry for yet another eyepiece question - i am about to pick up my celestron 130/600 scope and it only has a 25mm plossl.

so before i add a bunch of ep's to my christmas wish list, thought i better ask some advice first. i dont like really small eps as i have long eye lashes. so would i be be better off with something like a 10mm super wide field with good eye relief and a decent x2 barlow to get the equivalent of a 5mm?

when i put the brlow in, does it halve the fov and eye relief also, or does that remain unchanged?

if it remains unchanged, then i am happy to spend some wonga on a really decent x2 barlow and 10mm ep, which should give me 24+48 mag and 60+120 mag out of the 2 ep's.

would this be a good starting point?

many thanks,

nick

[ronin]

As everything budget is a factor however the BST Starguiders are almost the universal recommendation for a budget eyepiece with reasonable eye relief and good performance.

As you want the eye relief that knocks the Vixen NPL's out and any other plossl.

The planetary eyepieces give a similar eye relief for much the same cost.

Sky's the Limit sell the BST's and a range of planetary's.

They also have a WA eyepiece that is the same WA as the BST's and planetarys, no idea on their performance.

Telescope Service/Express have a range of planetarys that are said to be good on performance. 59 Euro a piece +6 Euro postage.

After that are the Celestron X-Cel LX's at £69 the last time I looked at FLO. Seems that Celestron have been releasing some new eyepieces however no idea of the cost nor performance. They are I suspect above the BST's in cost.

[Qualia]

I'm really happy with the X-Cel LXs. They're well corrected at the edges, have excellent eye relief and have been tested down to about f4. In my own forgiving f/10 there is a pleasent field of view, they're well corrected, there is no distortion at the edges, there is wonderful contrast and colour, and the star image is sharp, pin point, throughout. The x2 barlow is also a cracking piece of kit. I was fortunate enough to have tried it along with Tele Vue's basic barlow and rightly or wrongly figured that in the future the latter might cause me problems due to its length. Performance wise, with my inexperienced eye, I could see no difference. It is also worth pointing out that some folk have had trouble with the twist up eye guard coming off with the LXs, I haven't had this problem but I think it is worth bearing in mind.

As Ronin has already said, the BST range also come highly recommended and I've read some positive things about Meade's 5000 series. I also feel that if you can get your hands on russian eyepieces this might also be a worth while avenue of investigation. The Tal's 25mm, for example, is a lovely plossl to have in your kit and does - to a given degree - have comfortable eye-relief in the form of its rubber eye guard.

[tjr]

To answer your first question, a barlow will divide the FOV by it's power. Your FOV os calculated by dividing the eyepieces apparent field of view by the magnification it is giving, so, assuming you use a x2 barlow the FOV will half too. The eye relief will remain unchanged as this is down purely to the EY you are looking through.

To answer your second, yes, I think this would be a good starting point but some people like using barrows and some don't. As Qualla and ronin have said, both the x-cells and BSTs are quality eyepieces with good eye relief.

[LukeSkywatcher]

So the scope is 130mm in aperture and a focal legth of 600mm.

The Skywatcher Heritage is of similar opics and i find that Vixen NPL eyepieces (about £30 each) work exceptionally well. They are on par (so many have said who have tried both) with e BST eyepieces and they cost about the same.

Very sharp views (almost to the edge) and amazingly contrasty.

So i say its very safe to buy either NPL's or BST's. The BST's i hear have better eye relief, so they may be the ones to go with.

Personally i say forget about buying a barlow and just buy better eyepieces that offer the same magnification.

Regarding the Celestron x-cels...............

Lately i am reading here more and more about them from people who have them and they seem to be very highly regarded. They cost a bit more then i care to pay for a single EP, but that is just me.

http://www.firstligh...x-eyepiece.html

[rwilkey]

For the eye-relief you describe, in my view the answer lies in the BST Explorers/Starguiders, Plossls would be a pain at the shorter focal lengths. I prefer not to use Barlows, as they usually double the eye-relief, to an uncomfortable extent in my view. However, they are useful for experimenting when you are first starting out. But as already said, some people love them, some don't. I am in-between.

[Moonshane]

I don't know much about the physics but barlow lenses will certainly affect the eye relief of eyepieces used with it. this is usually variable depending on the type of barlow, the type and focal length of eyepiece. this is one reason I would never use a barlow with e.g. a 32mm plossl. see e.g. http://stargazerslounge.com/topic/152557-eye-relief-with-a-barlow/

Televue powermates and similar don't change the eye relief etc but they are not barlows.

[breezy]

_{ooh thats an interesting thread moonshane, i was under the impression that the barlow didnt affect eye relief after watching a scopesnskies video on you tube ??}

[CSM]

A good starting point would be something like the Skywatcher 7-21mm zoom eyepiece. It's reasonably good quality and you have a range of eyepieces quite cheaply 7, 9, 11, 15 and 21 - when I compared the 15mm option with a single Televue 15mm it was probably better! Chances are that you will find that you will use the 15 and 21 most often as viewing conditions won't be good enough for anything better.

[LukeSkywatcher]

The eye relief of the NPL does not bother me, but if its a factor in your choice of EP's then the BST's offer better eye relief and they cost the same as the NPL.