Better eye pieces

[JohnC260]

Hi with regards to better eyepieces, what would be a decent upgrade from what I have?

I was given an Explore Scientific 10mm 70° EP I quite like this and find it easy to use, the view seems crisp what are peoples opinions on this?

The others I use are what came with the scope Bresser 10mm and 26mm Plossl these are the main ones I would look to improve.

My other EP's are: Antares 2 x Barlows, and an Antares 90° Erecting diagonal, these I both like and seem and improvement upon the Bresser ones I received as standard are these ok EP's? 

I know the more you spend the better, are there any particular brands I need to look for when searching for EP's?  are there any I should avoid?

I'm liking the Antares stuff so far, is there are better brand in a close price bracket?

Edit: sorry using a Bresser Messier AR-90/900 Refractor. 

[rwilkey]

Hi John, that's a nice scope you have there, which I have had experience of recently when I recommended a friend to get it.  Now, eyepieces, it depends on how much you want to spend, my favourites are the ExSc 82 series, however the 62 series look pretty good and I would recommend going for these, you will never regret buying quality from the outset.  If budget is limited then you cannot go wrong with BST StarGuiders, very comfortable to use, items found here

https://www.firstlightoptics.com/explore-scientific-eyepieces/explore-scientific-62-series-ler-eyepieces.html

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

Good luck with your choices!

[JohnC260]

Thanks rwilkey I have an explore scientific EP and quite like it, thanks for the info I will go and have a gander! 

[Ruud]

Many people like the BST Starguider eyepieces. I have limited experience with them, but I know the 8mm is surprisingly good for what it costs.

Here's a list of some flaws that eyepieces can suffer from. To an extent, all eyepieces have them, but in really good eyepieces, they are controlled to the level of being unnoticeable. 

• Field curvature.
  If the focal plane of the eyepiece isn’t flat so that the centre and the edge of the view will cannot be in focus at the same time. As a remedy you can try is to focus halfway between the centre and the edge of the field, hoping that your eye can accommodate enough to get the rest sharp. Eyepieces without focal plane curvature are called “flat field eyepieces”
• Astigmatism.
  At the edge of the field stars won’t focus into points, but as lines. These lines will be either radial or tangential, depending on if you are inside or outside of best focus. In between, the stars there may look like crosses or ellipses.
• Chromatic aberration (CA).
  You can easily detect this as a coloured edge to the Moon. When the colour changes with the focus setting, you have longitudinal CA. If it is independent of focus, you have lateral CA. You can also have both.
• Spherical aberration.
  A spherical lens surface is the easiest to make to high and exacting tolerances, but won’t bring all the light to the same focus. Clever designs still use spherical lenses with different kinds of lens curvatures, lens thicknesses, refractive indexes and lens spacings, so the the errors caused by the various surfaces cancel each other out. Some designs have one or more aspherical surfaces, but others achieve better results without.
• Scatter.
  When the edges of lenses are milky white, light may scatter off of them and end up across the whole field. When lens surfaces aren’t sufficiently smooth halos of scattered light may show around objects. In both cases contrast is reduced and the image looks less crisp.
• Ghost images.
  When lens surfaces aren’t all properly coated, rays may reflect between them and cause ghost images.
• Angular magnification distortion (AMD):
  This is a geometrical distortion that does not affect sharpness. With AMD, the magnification differs across the view. Usually it increases toward the edge. This stretches out objects and makes circles at the edge of the field look elongated.
• Kidney Bean shadows.
  This too has no effect how sharp the image appears. A bean shaped shadow, which comes and goes and moves around as your head moves, causes part of the image to go dark. This happens somewhere between the centre and the edge of the view. If an eyepiece has this problem, you will notice it much more during daytime observations and observations of the Moon, than when you observe stars or deep space objects, as the problem gets worse when your pupil gets smaller.

The more experienced an observer becomes, the more he will notice any shortcomings in his eyepieces. Some choose the strategy of replacing bad eyepieces with the best eyepieces they can afford at the time, only to discover the need to replace those too, and maybe their successors as well, until years later they finally find an eyepiece worth keeping.

You can avoid buying eyepieces that in the long run won't be good enough. Give yourself time to discover what you need and while you're doing that, put some money aside for the purpose of buying a new eyepiece. 

Don't buy eyepiece+filter kits, btw, unless you think the case is by itself worth the money. Also, join a local club and visit s few star parties to discover how sharp sharp can be.