Will Better Eyepieces Enhance My Small Telescope's Sharpness?
I’m going to be contrarian here and offer a qualified 'No not really.' Here’s why.
Most eyepieces today, even very inexpensive ones, are made from good glass and usually have reasonably decent anti-reflection coatings, even if it's a single coating. I’ve looked through some of the Huygens and Ramsden eyepieces that have come with recent telescopes and some very old ones from a telescope I own that was built in the late 1950s. All of them provide sharp views in longer focal length telescopes.
However, there’s a qualifier: many telescopes today are shorter focal lengths. Think of a telescope as an entire optical system. While you can change eyepieces to alter magnification, it remains a system of lenses and sometimes mirrors. Shorter focal lengths are more challenging to focus across the entire field of view. The central area of the field of view is usually not an issue; it will be plenty sharp even with cheap eyepieces, though with a narrower apparent field of view. Higher quality, more expensive eyepieces help manage the shorter focal length's focused light and contribute to a wider field of view that's sharper from edge to edge. Sometimes, the focal length is so short that a corrector lens is needed to help the light be more 'flat' before it reaches the eyepiece, even if the eyepiece is pricey.
Understanding the whole system, considering the focal length/focal ratio, and the eyepieces you’re using is crucial to determining what will give you the best overall view.
Can Better Eyepieces Make a Difference?
The answer is "almost certainly yes" with some caveats. If you have a low-quality scope, better eyepieces won’t help. However, the combination of a wider field of view, a flatter field, sharpness to the edges, and better eye-relief will certainly improve your observing experience. The degree of improvement depends on these other factors.
My advice is to join a club, go to a club observing session with your telescope, and then ask other members if you can borrow some eyepieces to look through them in your scope. Everyone I’ve met in a club is happy to share eyepieces because they want you to have the best experience possible with your scope, stay enthusiastic about Astronomy, and keep contributing to the club. You’ll be sharing your upgraded eyepieces with new members before you know it.
In conclusion, while better eyepieces can indeed enhance your small telescope's sharpness, understanding the entire optical system and the specific needs of your telescope is key. Joining clubs and trying out different eyepieces can be a great way to find the best setup for your astronomy observations.