Need Advice on EP.

[Limey21]

Hello all, hopefully this is in the right place, i recently bought a 10" Skywatcher 250px Flextube, now i've had it a while i am looking to get some better quality eyepieces and now have my heart set on the Celestron X-Cel LX series as they seem good for the money and i really like the look of them,  so anyway my question is what would be the best choice if i could buy 2 of them from the whole set for my scope, i am getting the Celestron X-Cel x2 Barlow aswell at the same time.

Link with the sizes below.

https://www.firstlightoptics.com/celestron-eyepieces/celestron-x-cel-lx-eyepiece.html

 

i will get them all in time but for now 2 and the barlow would be fine.

 

any help would be great, as i have read about the lenth of scope being a factor etc, but i do not truley understand it yet

Thanks

Limey21.

[andyboy1970]

Have you tried them?

Not all eyepieces suit everyone, I for one don't get on with Celestron X-cel lx eyepieces and get kidney beaning (Black spots) in my vision.

If you can try other peoples.....

[Charic]

I love my eyepieces, especially the Starguiders, I think most of my  eyepieces may even work on the 250PX but your scope with its f/4.7 focal ratio may require some premium optics in order  to get the best out of the scope.
Its the reason I bought some  Tele Vue Delos eyepieces!

[Louis D]

At f4.7, I recommend you invest in a coma corrector for that dob to help any eyepiece better deal with the steep light cone.  I have the GSO 2" Photo-Visual Coma Corrector for Newtonian Telescopes and have parfocalized my eyepieces to negate the need for adding or removing spacers.  I can't believe I observed for 15 years without one.  It really cleans up the outer field by suppressing coma and flattening the field.

[Charic]

I forgot the sizes? I would have the 7mm and 18mm for starters if you went for the X-CEL LX.

I have  the BST  3.2mm and a 5mm and they get used the least, I use them on the Moon,  but their just too powerful for my scope for anything else, powerful degrades the image?  in comparison to say an 8 -12mm. Their also part of the 'set' so I have to have them! I think the 2.3mm and 5mm X-CEL LX may be too much for your scope ( unless like me, you like to collect in sets?)
I have a 6mm  EP to match my focal ratio f/6.  Your ratio is f/4.7 - f/4.8  depending on how you formulate?  A-250mm or A-254mm  so your ratio   rounded up  would suggest a 5mm give you 250x power to match the scopes capability, but the UK weather wont allow you this freedom, without some visual issues affecting your enjoyment. I  can push to 375x on the Moon, but anything else  at 375x is a laugh!

 

[Putaendo Patrick]

The magnifications which eyepieces will give for a specific telescope depend on its focal length. In the case of your scope, this is 1200mm. Divide this number by the focal length of the eyepiece to give the magnification. For example a 12mm eyepiece: 1200 divided by 12 gives a magnification of x100.

You probably have a 25mm eyepiece which came in the box with your telescope. Whilst not fantastic, these are generally good enough - so I'd make do with this for the moment. Later you may decide you want a low magnification 2" eyepiece - although more expensive, these can give really breathtaking views!

Considering two X-Cel LXs with the x2 Barlow, I'd go with the 18mm and the 12mm (effectively adding 9mm and 6mm through using the Barlow). This would give the following range of magnifications:

Old 25mm - x48

18mm - x66

12mm - x100

9mm - x133

6mm - x200

Magnifications of x100 and x133 would be useful for targets such as the planets. x200 is pushing towards the upper limit, but with good atmospheric conditions, would show tremendous detail on the Moon.

[laudropb]

I have a set of X-Cels and I like them very much, but I do not have a scope as fast as yours. I would buy a single eyepiece, say the 9mm X-Cel and try it in your scope before committing to any more.

[Limey21]

Thank you kindly all for the advice, it has helped me quite a bit, this forum is a valuable resource.