Eyepiece for 102ED Refractor

[Lews Therin]

Hi guys,

 

I’ve just purchased an Altair Astro 102ED refractor - 715mm focal length.   I’ve currently been using a Skywatcher 127 Mak, and some fairly cheap and cheerful 1.25” eps.

 

Over the coming months, I want to get some new much better quality eps - although having just bought the new scope, a new mount, and still needing a 2” diagonal…  I’m probably just going to purchase 1 new ep for now.

 

I currently have moderate quality eps of 5mm, 10mm, 20mm, 25mm - and a 2x barlow in 1.25”.   I am 34, wear glasses, and I’m also in a heavily light polluted area.

 

For my main primary lens, I’m looking for something to give a very nice wide view - but preferably not (much) above £100.    I’ve read quite a few reviews of different eps, although in many cases, the people involved had significantly different scopes.

 

The types I’ve been looking at are:

*Skywatcher Aero ED 2” (30mm or 35mm) - 68ºFOV

*Baader Hyperion 68 21mm/24mm (bit confused, but saw somewhere that if used as 2”, they are 30mm??) - and can be modded with rings to give several other focal lengths.

*Baader Hyperion Aspheric 31mm 72ºFOV - above what I want to pay, but appears to get amazing reviews.

*Explore Scientific 68º Maxvision 34mm

*William Optics SWAN 33mm 72ºFOV

 

I plan to purchase a 2” barlow as well, or at least very soon.

 

What are your suggestions please?   Is 30-35mm good?   20-25x magnification with a good FOV sounds promising - especially after “looking through a straw” with my 1500mm focal length Mak.      Also, for a planetary ep, what would be a good budget option?  My 5mm seems to have quite bad CA, and I was wondering if I could get away with something like Skywatcher’s UWA Planetary Eyepieces (around 4/5/6mm)?

 

Thanks for any advice and wisdom…

[John]

Hi,

One of my scopes is a very similar refractor - a Vixen ED102SS which is F/6.5.

Looking at the eyepieces you have listed, I'd say that the Baader's are not that well corrected in faster scopes so they would not be my 1st choice. The Hyperion is a 1.25" eyepiece but has a section of barrel that is 2" fitting - it's still a 1.25" optically though.

I've not been that impressed with the William Optics SWAN's in faster scopes either so that would leave the Aero ED which is a pretty good 2" eyepiece for the price and the ES Maxvision which is probably the best corrected of your list.

With regards to the barlow, barlowing an eyepiece such as the ones you list is not without it's problems because the already quite long eye relief is lengthened by the barlow so finding a comfortable eye position can be awkward. The Tele / Focal extender type amiplifiers are much better in this respect although the cost is higher I'm afraid.

The focal length range of 30-35mm is fine for the scope although you may well find that something at the lower end of that or even a 28mm does a better job of producing a darker background sky in your light polluted area.

For higher powers you don't need to worry about 2" eyepieces because they don't provide any benefits in shorter focal lengths. If the optics in the scope are decent than 200x should be a useful high power for which you need a 3.5mm focal length eyepiece.

What eyepieces do you use with your 12" GSO dob ? - obviously it would make sense if anything you do purchase will work well with that too.

There are so many choices these days !

[Ricochet]

From that list I would go for the 34mm Maxvision, although as John says, you may find the darker background sky in the 28mm version more useful if the light pollution is bad. I wouldn't bother with the 2" barlow though, because unless you go for more expensive wider AFoV eyepieces in the future, it will be your only 2" eyepiece and you could spend the barlow money on a 1.25" eyepiece instead.

[Lews Therin]

Hi John and Ricochet,

 

Thanks for the replies.   I'd forgotten to update the signature - unfortunately I had to sell the dob, and I also sold a decent 26mm 2" that I had used with it.   

 

I have seen the Hyperion 71º aspheric 2nd hand, and that is a proper 2"...     The ES Maxvision doesn't seem to be much different in price from the Aero.        That leaves me with a choice of 28 or 34mm.    As for the barlow, I've never had an issue with my standard 1.25x...  I've used it with each of my eps at some point, and other than a reduction in quality, I don't remember much of an eye relief issue.    

 

Maybe add a better planetary ep to list at the same time then.

[triton1]

I have the 28mm Maxvision and can thoroughly recommend them.

[John]

47 minutes ago, Lews Therin said:

Hi John and Ricochet,

 

Thanks for the replies.   I'd forgotten to update the signature - unfortunately I had to sell the dob, and I also sold a decent 26mm 2" that I had used with it.   

 

I have seen the Hyperion 71º aspheric 2nd hand, and that is a proper 2"...     The ES Maxvision doesn't seem to be much different in price from the Aero.        That leaves me with a choice of 28 or 34mm.    As for the barlow, I've never had an issue with my standard 1.25x...  I've used it with each of my eps at some point, and other than a reduction in quality, I don't remember much of an eye relief issue.    

 

Maybe add a better planetary ep to list at the same time then.

Barlows do extend the eye relief but thats not an issue until you use them with eyepieces that already have reasonably long eye relief !

In your heavily light polluted area (to use your words) I'd definitely go for the 28mm over the 34mm.

 

[mikeDnight]

The Baader 35mm Eudiascopic would give superb low power views in your ED. It's not a bulky eyepiece, which is a blessing, and it is very comfortable to use having long eye relief and a large eye lens, and superb optics. It is slightly over your prefered price but if you're interested its currently available from astroshop eu.

[Ricochet]

I just remembered there is a 28mm Nirvana in the classifieds for £100. I recently bought one myself and the quality is at least the equal of the ES eyepieces. 

 

 

[Lews Therin]

Thanks for the added replies.

 

The 28mm Nirvana looks good, and all of the reviews I've found have highly recommended it.   Couple of questions though...   It says the ep weighs 1kg, and it is clearly very large, so...    Is it going to fit and work well on my scope with a 2" diagonal (I'm planning to purchase the matching Altair Lightwave one - http://www.rothervalleyoptics.co.uk/altair-astro-lightwave-2-dielectric-diagonal-push-fit.html which appears to be a good quality one)?   I know some cheaper diagonals bend, or just can't support that kind of weight.    

Secondly, all of this will be mounted on a Vixen Porta 2 mount, which says it supports 6.5 or 8kg scopes (depending on which site you go on).   My tube weighs 3.9kg, so with the ep and diagonal will weigh about 5kg.   Is there going to be any kind of balance issue??   The Vixen can be tightened or loosened as necessary.

[John]

I used to use my Vixen on a Porta mount (the Porta I) and that included using the 28mm UWAN / Nivana and my own 31mm Nagler. If you mount the scope with the weight towards the front end it should be OK.