Nagler but which one??

[John]

The Nagler / Nirvana are ultra-wide angle eyepieces with an 82 degree apparent field of view. The BST Explorer is what I'd call a semi-wide angle with a 60 degree apparent field of view. They all do the same job but the Nagler / Nirvanas show a wider patch of sky which can be helpful if you have an un-driven scope as objects stay in the field of view longer. They also all have the same size exit pupil, that is the diameter in mm of the bundle of light that comes out of the eye lens of the eyepiece. The exit pupil size is determined by the focal length of the eyepiece and the focal ratio of the scope it's being used in.

Some folks like the views through ultra-wide angle eyepieces and some are not so keen.

Eyepieces are more complex than scopes in many ways !

[mdhardy01]

Ok thanks John

So using a nagler/nirvana on say Saturn would give me the same mag and veiw of the planet but with a nagler/nirvana I would see more around the planet ?

Matt

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[spaceboy]

Some text on exit pupil http://www.singularsci.com/Accessories2.htm

[John]

Ok thanks John

So using a nagler/nirvana on say Saturn would give me the same mag and veiw of the planet but with a nagler/nirvana I would see more around the planet ?

Matt

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Broadly, yes. The optical performance will be a little better with Nagler / Nirvana over the BST Explorer as well. As the former cost 3x - 4x as much as the latter you would hope that would be the case !

It's worth noting that the performance gains as eyepieces get more expensive get proportionately smaller - neither the Nagler or Nirvana is anywhere near 3x - 4x "better" than a BST Explorer any more than a Tele Vue Ethos, which costs twice as much as a Nagler, is twice as good again. Small incremental gains in performance is what the extra £'s buy.

Astronomers tend to pursue small performance increases with some vigor though - and small improvements are sought after

[Ags]

My reference was to galaxies not globulars Ags. If I am wrong I will happily hold my hands up and admit I am.

I think for galaxies you're are broadly right, but the eye's ability to distinguish an object depends partly on relative contrast (influenced in a complex way by the exit pupil - more magnification can up to a point increase contrast) and partly on the size of the object - a small fuzzy patch is less visible than a larger fuzzy patch, even if they have the same surface brightness.

I used globs as an example as they came up earlier in the thread...

[spaceboy]

In one of my threads optimal exit pupils were explained by sixela (who seemed very much in the know) but for some reason she chose to leave the forum and all her posts were removed from the thread. I'm not sure but I think this was the thread in question http://stargazerslounge.com/showthread.php?t=119275&page=2 it may be beneficial to Matt regards understand exit pupil even though half the posts missing ?

[mdhardy01]

Spaceboy thanks for the thread link that was just what I needed

So do you think the addition of a 7mm 82 fov ep would be a good idea

The closest I have is the 8mm bst I also have a 6mm wo spl which is great on planets but i am really getting an interest in globs so thought the wider fov would be beneficial ? Is this correct thinking or am I just wanting a new ep lol

Matt

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[Ags]

It is a pity Sixela vanished... She was a he though.

I find M13 fits in nicely in a 60 degree EP at 150x - I don't know if that helps...

[Moonshane]

Spaceboy thanks for the thread link that was just what I needed

So do you think the addition of a 7mm 82 fov ep would be a good idea

The closest I have is the 8mm bst I also have a 6mm wo spl which is great on planets but i am really getting an interest in globs so thought the wider fov would be beneficial ? Is this correct thinking or am I just wanting a new ep lol

Matt

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you always need a new ep

[spaceboy]

It is a pity Sixela vanished... She was a he though.

Sixela - Alexis ?

Matt: Although the conditions this time of the year are not ideal I gave M13 a go last night in my Explorer with the 3-6 zoom and 7mm Nirvana. Although the 3-6 zoom only has 50° AFOV I gave it a go to get an idea what magnification worked better. I came to the conclusion the 7mm x142 offered the brighter more resolved view of the stars and the 82° of the nirvana offers plenty of room around the glob so that it didn't look claustrophobic. As I said before though the best all night glob session I ever had was with a 6mm radian x166. Obviously seeing and transparency may have been exceptional that night but the 60° AFOV of the radian still worked well.

I think the trouble is that when you mention a televue product in your opening thread most of us immediately get the impression that you are looking for a level of quality not every eye piece can achieve and so some more budget options are not offered in to the mix. I personally found that shorter focal length eyepieces do not seem to suffer as much as longer focal length EP's and so if you are prepared to make what I consider to be negligible compromises you will have more options open to you. As you mentioned you have a BST, have you not considered trying a TMB clone ? These offer 58° AFOV and a 7mm focal length that will sit between your 6mm Spl & 8mm BST. They are only £36 new and offer views similar to that of the BST. If anything you would get to see if the magnification and FOV works for you and sell at a minimal loss if not. If you feel the 7mm works fine and an upgrade is of worth at least you will know it is worth throwing some money at.

[mdhardy01]

Hi spaceboy

Thanks for the reply

I think the real problem I had was green envy

The idea of having a televue in my collection appealed more than what it would actually do for me

Rethinking the need for a nagler has now led me to the decision to get a nirvana.

The BST does offer great views but I do think I need just s little more the SPL gives just a little too much

Soma nirvana would hit the sweet spot with a wider FOV to boot

Also the BST I find doesn't quite give the contrast and I would hope the nirvana would give slightly better

Don't get me wrong I love my BST but feel I could just achieve more

So to conclude i will get a nirvana once FLO have them back in ( they had them yesterday but not now??)

I would like to thank everyone for their input SGL truly is a wonderful place to be a member

Many thanks

Matt

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[Codmate]

You don't have to spend 'Nagler money' to buy a Nagler.

I have an 11 and a 3.5 and saved £100 on each one...

One option you have mdhardy is to do what I did and set up a saved search on the bay.

It will mail you if anything comes up which matches the search. Then you can win the auction for a great saving

Also check the astro buy and sell!

BTW - I reckon the 7mm is what you need.

[John]

The "going rate" for a used but excellent T6 Nagler should be in the £130-£150 range although I've seen some folks asking more than that since the Tele Vue price rises earlier this year.

The Nirvana 4mm - 16mm's cost around the same new as a used T6 Nagler but can be bought for £80 or so, used. Occasionally much less....

Pentax XW's seem to fetch a little more than the T6's on the used market.

The good thing about buying all the above used is that you will be able to get most or all of your investment back if you decide to sell them on. There always seems to be a market for quality gear if it's in good condition

[mdhardy01]

Many thanks one and all

Have been looking on abs but nothing at the mo apart from a tv 9mm

Might just keep my eyes open and see what comes up

May even put up a wanted on abs

Matt

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[mdhardy01]

Don't suppose any of you have one going spare????????????

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[mdhardy01]

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[mdhardy01]

My wanted worked on abs

Will soon join the green brigade with a nice 7mm nagler

Happy days

Matt

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[John]

My wanted worked on abs

Will soon join the green brigade with a nice 7mm nagler

Happy days

Matt

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Congratulations

Is it one of the Type 6's or the earlier Type 1's ?

[mdhardy01]

Hi John

Type 6

What would the difference be ?

Haven't got it yet as away but been told its only 6 months old

What should I check for?

Thanks

Matt

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[John]

...Type 6

What would the difference be ?

Haven't got it yet as away but been told its only 6 months old

What should I check for? ....

The Type 6's have more eye relief and better quality lens coatings. A T6 will cost around £140-£150 used wheras a T1 should be around £100-ish.

If it's 6 months old it should be in really excellent shape. There may be a few light marks on the chrome barrel where it goes into the focuser but otherwise no marks / scratches, unless declared at time of sale. The optics should be unmarked of course, apart from few specs of dust which can be blown off with a bulb type blower.

You want both end caps (ideally originals) and if your are being picky the original box and paperwork will help re-sell it if you ever need to.

[mdhardy01]

Hi John

Getting it for £160 which I thought was ok

Have been told it comes with eye caps and box so I thought at about 6 months old not a bad deal but I will give it a good check over before I part with my hard earned

Matt

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[John]

That sounds fine. The Tele Vue price rise earlier this year has caused sellers to ask a bit more I reckon.

I still have a 3.5mm Type 6 which is my ultra-high power eyepiece

[mdhardy01]

Must say most of the nags I've seen in abs have been in the 150-190 price range so thought it was ok will post after I've seen it and had first light as to how I like it

Matt

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[mdhardy01]

Oh god done it now

Just bought a 9mm nagler from telescope service

And am still thinking of getting the 7mm but at the price TS are doing them is it worth just saving a bit longer and get a new one?only about £60 more for a new one

Thoughts welcome

Matt

[John]

I've bought all my eyepieces used and saved £hundreds in the process. If / when I ever decide to sell them on I can recover 90%-100% of the price I paid. So my recommendation would be to buy nice used ones as far as possible so you don't have to take the depreciation !