How to Clean a Telescope Lens

As with any piece of equipment, a telescope will get dusty for use or lack thereof. This might affect the quality of the image, as well as its performance in general.

But of course, this doesn’t mean that it will be the end of the world since it’s possible to clean it up.

This has been a major concern for both experienced and new astronomers, and rightfully so.

Fret not, this article will help with the process so the observer can go stargazing faster than they can say “Eclipse”. With that being said, let’s jump right in.

First things first…

Before delving into the main subject of this article, it is important to know that the mirrors in a reflector telescope shall not be cleaned under any circumstance.

This might sound far fetched and some might even object by saying that they’re careful enough, but there is a reason behind it. Mirrors inside a telescope operate differently, which is why the experts at Love the Night Sky recommend to have them professionally cleaned.

While it’s true that it would be more expensive in comparison, the price to pay will be worth it. It might seem evident, but the chances of placing them in the wrong order, or damaging them on the process, are high, so it is important to have them treated by someone who would take good care of them, such as a professional.

The Cleaning Process

Now, when it comes to cleaning lenses, this is a delicate process. However, good results can be achieved with a decent and affordable kit.

There are plenty of options in the market, so it cannot be stressed enough how important it is to choose wisely.

One great idea is to check for reviews on which one provides the best results before investing in the “weapon of choice”.

Keeping this in mind, cleaning lenses can be done safely and thoroughly at home, especially during current times.

Following the steps below is a must to achieve good results while being careful enough not to overdo it.

What does this mean? Simple: If the telescope is clean enough, there’s no need to apply the others, mainly because this could damage the artifact.

Prevention is the first step

The first stage is to protect them from getting dirty. Extremely evident, yes, but this should not be overlooked.

It is advisable to use a cap, although this can be replaced by saran wrap if the observer doesn’t own one at the moment.

The same thing goes for the lenses at the eyepiece, although it’s best to keep in either a protective case or a ziplock bag while they’re not being used.

Why does it get dirty, one might wonder? Well, direct contact with eyelashes can be enough to do so since they carry oil that can get on its surface.

If this is a common occurrence, getting an eyepiece that allows the user to look through it from a longer distance should do the trick.

With that out of the way, how does one remove the dust that accumulates in the lens?

The answer is simple: covering the end of the telescope above the lens while sucking the air from the other side.

However, this is not the only method for dusting them off, thankfully. Another option, and a better one, is to use an air blower.

They’re often included in cleaning kits, sucking in and blowing out clean air. An alternative to this is compressed air, but it is considered to be trickier than a regular air bulb, so proceed with caution.

The next step is using a brush to remove the dust, although it’s not mandatory if the user considers that the lenses are clean enough.

Brush your way clean…

However, if the owner wants to go through with it, it is recommended to use a very soft brush, which should be kept in a bag if they’re not cleaning lenses.

This will prevent it from gathering dust, something that would be counter-productive for the task at hand, cleaning it with an air blower once done.

The brush’s purpose? Flicking off the dust with gentle strokes from the center to the outside of the lens.

Once done with the brushing, cleaning the scope with a microfibre cloth follows, while softly rubbing it on the surface, without adding the fluid for this stage, since it’s better to do it while dry.

For remaining oil and water spots after using a microfibre cloth, it is advisable to use a clean rag while fogging the lens with one’s breath and rubbing it gently once again.

If the grease won’t come off the lens, then the cleaning fluid gets in the picture, pun not intended.

This is considered the final stage of the cleaning process unless the other steps were enough to return it to its former glory.

For this step, one or two drops of fluid will suffice, without dropping it directly on the lens. It is important to avoid this at all costs, mainly because it could pull grime inside the telescope and the eyepiece.

Perfect technique…

The next thing in line for this process is a gentle, circular motion from the center to the edge of the glass, similar to what one would do while using the microfiber cloth without the cleaning fluid.

Once finished, doing the same thing with its dry part to remove any excess.

If this doesn’t work and there are still visible spots, I personally recommend putting a drop of the cleaning fluid onto the end of a Q-tip and using it to remove any grime that might have slipped.

Being firm yet gentle is a must, considering that extra pressure can be damaging and would result in having to replace it.

Keep your lens clean…

Cleaning the telescope lenses regularly can be crucial to a telescope’s performance, mainly because they rely on them, among other things, to help the user navigate through the cosmos in the comfort of their own home.

Those who wish to indulge in astronomy not only need to know which planets and constellations they’re going to see or the best models to start stargazing with, but also how to take proper care of them.

After all, what would be the point of having a powerful tool if one doesn’t make it last? Make every cleanse count!