EPs to keep clear of or not buy for my scope

[dc240969]

Having just recieving a new SkyWatcher SkyMax127 'SynScan'AZ GoTo l wanted to ask a few questions on eye pieces. It came with 3 and a 2x barlow. I am still feeling my way round with the scope and have yet to set it up properly. I was only home a few days, missed the last full moon, so only viewed what was left of the moon when l could. I cant wait to get home to set it up properly outside. Regarding EPs, is there anything l should not consider for this scope and anything l should really look at getting. I dont want to throw money at EPs just to have a box of them l wont or cant use.

[heliumstar]

18mm BCO works really, really well in my 127 Mak. Decent eye relief and Luna is really nicely framed with it.

[John]

BCO = Baader Classic Orthoscopic, just in case you have not come across it

With the long focal length of the maksutov-cassegrain most eyepieces will work pretty well with it to be honest. Which 3 eyepieces came with the scope ?

[Cosmic Geoff]

21 minutes ago, dc240969 said:

Regarding EPs, is there anything l should not consider for this scope and anything l should really look at getting. I dont want to throw money at EPs just to have a box of them l wont or cant use.

Don't rush to spend money on eyepieces till you have tried out those that came with it.  That said, the 9 or 10mm original kit eyepiece that usually comes with such scopes is not much good and you should think about replacing it.  This scope has a relatively long focal ratio and will not be fussy about eyepieces, so most well-made types will be found to work, including the humble Plossls.

[bingevader]

Your budget per EP is always a good place to start, as you can spend as much as your pockets are deep!

But, as Cosmic Geoff has said, don't rush into it, and as you said yourself, feel your way round first.

You'll probably be able to live with the ones you have for a bit, so filling gaps like Heliumstar has suggested would be better than starting off by replacing eye pieces.

I actually prefer viewing what is left of the moon rather than the full moon.

The full moon tends to be a bit bright and washed out, whereas a crescent has a bit more relief and shadow, allowing you to pick out detail more easily.

[dc240969]

I think the EP that came with it was 8,10 and 25, and barlow. I picked up a set of Aspheric eyepieces 4,10 and 23 with 62 degree for a few pounds and they are clearly better, well the 10 and 23 are but l havent had a chance to use the 4. But as said, once lve got the scope outside and not just pointed out my top window all should be more noticable what one is better than others. 

[John]

I think the 4mm is going to be pushing things (375x) whatever it's quality is. The others should be useful though.

BST Starguiders are nice for their price, easy to observe with and have wider fields than standard plossls etc:

https://www.firstlightoptics.com/bst-starguider-eyepieces.html

 

[bingevader]

Me too! 4mm would be a bit much.

As a basic rule of thumb, you won't get more magnification than provided by double the aperture of your 'scope in mm.

So 127 x2 = 254x would be a (1500/254=5.9mm) 5.9mm EP.

[Louis D]

Given the long focal length and slow f-ratio, there won't be much need for the 2x or 3x barlow.  The limit for eyepiece power is generally a function of exit pupil which is calculated by dividing the eyepiece focal length by the telescope f-ratio.  The limit for exit pupil tends to be between 0.5mm and 0.7mm.  Some folks with fewer floaters in their eyes than me can make use of even smaller exit pupils, but the telescope optics might not support it.

Thus, for a 0.5mm exit pupil, that would be a 6mm eyepiece (6mm/11.8=0.51mm).  That, or a 2x barlowed 12mm would yield roughly the same exit pupil.  I find in my 127mm Mak that I don't like to go below about a 9mm eyepiece yielding a 0.7mm exit pupil.  Try the 8mm and 10mm eyepieces both natively and barlowed to see for yourself the effects of diminishing exit pupil for yourself.  You could even try the 25mm with the 2x and 3x barlows to see which combinations work best for you.  Be aware that barlows tend to extend the eye relief on longer focal length eyepieces, so you may find yourself struggling to hold the field of view in the barlowed 25mm due to this.

The 23mm Aspheric works pretty well at longer focal ratios and tends to max out the true field of view in the 1.25" eyepiece format.  You could try barlowing it as well.  Only you can decide what combinations work best for you.

[Geoff Lister]

I have the same Skymax 127, and usually start observing with my 32mm Plossl. As I understand it, the 32mm Plossl gives the widest field of view that can be achieved at a reasonable price with a 1.25" eyepiece, and has good eye relief for glasses wearers. The Mak. also works well with the Celestron 8-24mm zoom; particularly to find the best magnification / visual clarity compromise on the planets. The zoom will also work well with the x2 Barlow, if the seeing conditions permit higher magnification.

Geoff

[dc240969]

Thanks for the information. I have picked up a William Optics zoom and look forward to trying it out when l get home in April.

[Steve Clay]

I have the same scope.on the AZGTI. I've bought the following EP's

SW 32mm plossl 

BST Starguider 12 & 8 mm

SW 25 came with scope the 10mm was dreadful. 

[LukeSkywatcher]

All I can say has been said already.

Don't rush to upgrade your eyepieces. Get to know them and the scope.

The full Moon isn't really worth observing. It's brightness washes out detail. Observe it either side of full.

The 4mm eyepiece really is pushing the limits of the scope. It would have to be an exceptionally clear night with amazing "seeing" and transparency to get use out of it.

The 127 scope is a popular choice. Enjoy it.

[Louis D]

2 hours ago, LukeSkywatcher said:

The full Moon isn't really worth observing. It's brightness washes out detail.

Surprisingly not with binoviewers, though.  I think the fact that both eyes see the same brightness allows them to see detail that gets washed away in monoviewing because your brain is trying to integrate a pure black image with a very bright and detailed image and fails miserably in the process.  For most astro views, your brain is integrating a dim view with an all black view and does an admirable job in the process.

[Greymouser]

1 hour ago, Louis D said:

Surprisingly not with binoviewers, though.  I think the fact that both eyes see the same brightness allows them to see detail that gets washed away in monoviewing because your brain is trying to integrate a pure black image with a very bright and detailed image and fails miserably in the process. 

For you maybe, but not me. My eyes/brain struggle with that bino view, it is just not fun. To the point that I am going to have to sell my 20 x 100 binoculars! Which is annoying.