Eyepiece first major step forward

[TiTanecd]

Hey guys

I have a XT8G arriving in 2 weeks and thought of buying the first of my EPs that I wish to start getting in the next few months.

Many reason will be for DSO and Planetary viewing. The scope comes with an Orion 25mm (56fov).

I want to get a large fov DSO EP first.

Selection in SA isn't great. They have 3 ranges.

Celstron Ultima LX, Orion Stratus and the Orion Q70.

I am aiming for a Low, Med and High power range for DSO.

Low: Orion Q70 (either 32 or 38mm) - I know these have high coma and esp for a f/5 scope. How does this compare to other 70 deg EPs?

Med: LX17mm or Stratus 17mm

High: LX8mm or Stratus 8mm

Planet: I'll get a 5mm later on.

The scope is 1200mm.

Are these EPs good for this scope and DSO. I want them to last but can't afford anything more than these. Panaview / TV / etc are like an extra $150 here to ship...

[rwilkey]

Hi there, your selection and reasoning seem sound, the 8mm is probably the highest you need to go, giving you 150x on your scope.  Forget the 5mm, that will be too high in my opinion, giving 240x, good on Saturn when the skies are perfect, but not any other time.  150x on planets is the sweet spot in my view.  I would suggest the 32mm Q70 for low power use. The 17mm is a good medium power giving 70x, will be good clusters and planetary nebs.

[rowan46]

Would it be possible to import directly from the states?

[russ.will]

As the XT8g is F6, coma (which is scope generated) won't be too much of an issue, but astigmatism which is eyepiece generated is. The Q70, which is a 5 element Erfle (like the SW Panaviews and coincidentally have the same focal lengths) will have plenty of that, so stick to the 32mm which will be plenty wide enough without filling the view with seagulls.

I believe there's a common heritage between the Baader Hyperions and Orion Stratus - I could be wrong. The one Hyperion I tried left be a bit underwhelmed in my then F5 200mm Newt compared to my BST Explorers which were a much cheaper EP, but at F6 and longer there seem to be a lot of very happy owners.

This is a bit of a curved ball and only really helps you with the longer focal lengths, but Explore Scientific Europe do a de-badged Meade Series 5000 SWA under the Maxvision brand. There's a minor amount of discussion with respect to the exact similarities, but what is not in doubt is that there's a gnat's whisker in it. The Meades retailed for closer to 3x the the Maxvision prices and are very much more at the Televue end of the performance scale - They are very, very sharp and much better corrected towards the edge of the FOV than anything yet mentioned.

I've had a quick look and ES don't quote a price for shipping to SA, but as both China and Peru are quoted as 69 Euro, it would certainly be worth asking. Two EPs should ship for the same amount which suddenly makes them a very attractive proposition. The 16 & 28mm may be two of the sharpest EPs you ever look through and the only thing I would replace them with would be Televue.

Russell

[Reeny]

Maxvisions were recommended here when I was upgrading from Plossls.

My most used combination is the 16mm MaxVision with the GSO / Revelation 2.5 Barlow (the 3-element version)

It always delivers.

Sometimes 200x mag is too much for the 8" Dobsonian.

I calculate the Barlowed 16mm MV to be 165x on my 1200mm FL scope.

The Revelation Barlow is nearer to 2.2 or 2.3x.

A 28mm MV at 43x mag will work well with the 16mm at 75x, and a Barlow up to 150ish.

Eventually you will need a good 6 or 7mm to get you nearer to 200x magnification.

Maybe a Delos or similar when the funds allow.

In the meantime a low power EP with the 16mm Maxvision (and a Barlow) should fill the gap OK.

[Reeny]

The Explore Scientific 82 degree 6.7mm might be another one to look at for maximum attack.

A 1200mm scope will give 180x magnification.

[TiTanecd]

Very nice site, I'll take a look at them. 

Tx guys for your help and some clarification on the coma.