Good eyepiece for lunar with 130P?

[RobertI]

I'm off to Cornwall with the family for a hol in July and am hoping for a bit of astro while there. I am planning to take the Heritage 130P on the SkyProdigy mount and am expecting to do mainly lunar as it will be fairly prominent. I have a 5mm BST e/p but am looking at a low cost 4mm to give a bit more mag whilst keeping the exit pupil a reasonable size ( I find 1mm exit pupil on the moon is very comfortable but 0.5 mm is very uncomfortable, so I believe 0.8mm and 163x mag should be as far as I can go with this scope, open to other opinions though). Can anyone recommend a decent 4mm eyepiece that wont break the bank, and is appropriate to the capability of the scope? Eye relief shouldnt be a huge issue.

Shortlist so far:

• Skywatcher Planetary UWA 58 degree FOV, 5 element, £39
• Vixen NPL Plossl 50 degree FOV, 4 element, £34
• TS Optics High End Planetary HR, 58 degree FOV, 6 element, £61

Currently thinking that the Vixen might be the safest bet? Any help appreciated.

Thanks

Rob

 

 

[johninderby]

A bit above your budget but a great eyepiece that is nearly as good as the Nagler but only £75.00 at the moment

 https://www.harrisontelescopes.co.uk/acatalog/ovl4nirvana.html#SID=1677

[RobertI]

Thanks John, that is quite a recommendation, £75 for Nagler like performance! Very tempted. Any idea how heavy heavy/bulky it would be compared to say my 10mm Hyperion? On the Heritage the plastic platform holding the focuser ‘flexes’ if heavy and/or long eyepieces are used, not sure this affects the view in reality, but just wondering. I notice the literature says good for scopes under 1000mm FL, any idea why? I always thought the relevant factor was focal ratio?

[johninderby]

It’s 165g.

Don’t know why theey say 1000mm as that is not relevant. The 7mm works great in a 1900mm fl scope.

[RobertI]

Great thanks John. I shall weigh the Hyperion for comparison, but I think we may have a winner. 🙂

[RobertI]

It might also give my little 72mm frac a new lease of life too!

[Geoff Barnes]

50 minutes ago, RobertI said:

Skywatcher Planetary UWA 58 degree FOV, 5 element, £39

Hi Robert,

I've recently been using this EP in my 12 inch Dob and I have to say it has absolutely blown my socks off, stunning performance for such a low price. Obviously my scope has a much larger aperture than yours but I really think you should consider giving it a try.

[RobertI]

Thanks Geoff. Now it starts to get difficult! 😆

[johninderby]

LThe big dufference compared to the planetary eyepieces is that the Nirvana gives a brighter image.and is a bit sharper plus that wider fov.

The planetaries are a good buy though. 

Edited May 18, 2019 by johninderby

[RobertI]

7 minutes ago, johninderby said:

The big dufference between the planetary eyepieces is that the Nirvana gives a brighter image.and is a bit sharper plus that wider fov.

That would also be a big plus for viewing clusters and globs I guess. Just weighed the 10mm Hyperion, it’s 380 grams! More than twice the weight of the Nirvana! So weight not an issue. 👍

[johninderby]

I just tried the 4mm in my Bresser F15 mak. Works surprisingly well on the moon although with the full moon only good for looking at a few craters on the limb. A 23mm was better tonight but lots of clouds so gave up and came back in.

[RobertI]

8 minutes ago, johninderby said:

I just tried the 4mm in my Bresser F15 mak. Works surprisingly well on the moon although with the full moon only good for looking at a few craters on the limb. A 23mm was better tonight but lots of clouds so gave up and came back in.

Crikey, that's 425x and .25mm exit pupil by my reckoning! That it worked well was a testament to the eyepiece, and to your eyes.....and the scope...and the seeing. Perhaps I'm just a wimp with my low powers!  

[johninderby]

The 7mm Nirvana is better for observing the moon really but just wanted to try the 4mm. Might use it on nights of great seeing. 

[John]

I've owned one of the Nirvana 4mm's (the old style body) and it was a really good high power eyepiece

[RobertI]

7 hours ago, John said:

I've owned one of the Nirvana 4mm's (the old style body) and it was a really good high power eyepiece

Thanks John, good to get confirmation. 

[bingevader]

I have the 4mm Nirvana too.

It's great in my (slightly slower) 8" dob.

[mikeDnight]

I'm a big fan of the Nirvana, but if not breaking the bank is an issue, then a good barlow will allow high power and maintain good eye relief. I'm a big fan of B arlows too!