How To Choose Telescope Eyepieces

For those who are just getting into learning about telescopes, you may feel a little overwhelmed by all of the choices you have available concerning telescope eyepieces. With a little background knowledge and deciding what exactly you are interested in using your telescope for, you can confidently choose a telescope eyepiece to fit all of your scoping needs.

It is important to understand how telescope eyepieces actually work so you can be sure to select ones appropriate to the activity you will be using your telescope for. Every telescope utilizes a lens or a mirror and some even use both. They are used to collect incoming light and in turn outline a figure from that light. A telescope takes the figure formed by the mirror or lens (or both) and enlarges it so you can see more details in said figure.

When shopping for telescope eyepieces, you will notice in most cases that there are particular markings on each lens. Generally these markings consist of numbers and some even incorporate letters as well. These serve the purpose of identifying what is known as the focal length. For instance, an eyepiece marked “25mm” lets you know that this particular lens carries a focal length of 25 millimeters and in turn allows you to calculate the amount of magnification that particular eyepiece will supply. Some eyepieces have other markings on them like “H”, “PI” or “SR”. These identify the kind of eyepiece it is. This refers to the optical design of the lens and usually classifies how much glass is used in each piece.

By knowing what the markings on telescope eyepieces mean, you will able to choose lenses that meet not only your telescope’s design but your particular viewing aims as well. There are simple formulas you can find online to determine the exact magnification particular eyepieces will provide. Generally you will need a couple of pieces of information (like your telescope’s focal length) to determine the answer to the formula. You may even be able to find an online calculator for an automated answer to your particular lens search.

When looking for eyepieces for your first telescope, there are a few tips you can follow that may help you invest in the best lenses. You want to be sure your telescope accepts 1.25″ eyepieces. Telescopes that accept two inch lenses are fine as you can find adapters relatively easily that will take the 1.25″ size. Another tip is that if your scope comes with two different lenses, you are looking for one of them to generate a good low  power magnification while the other generates a higher level. Generally, the best entry level eyepieces will include a 25mm focal length and a lens within the 10m to 7mm array.

Today’s technology can be very confusing, creating some challenges for consumers trying to find the best technology at affordable prices.