Cleaning Telescope Optics Quickly And Safely

Cleaning telescope optics is a question that gets thrown about a lot. In truth cleaning our optics isn’t something that needs doing all that often. In fact over-cleaning them could be detrimental to their health. So clean the telescope lenses or mirrors only when they begin to get really bad, or begin to affect image quality. In this article I’ll share my workflow for how I treat my telescope lenses, filters, camera sensors and camera lenses.

What You’ll Need

It makes sense to begin with what’s required. I use 4 items to clean my optics:

  • Camera Lens Rocket Blower
  • Lenspen
  • Baader Wonderfluid
  • Microfibre Cloth

With these, I can quickly and efficiently clean my equipment and be sure of its quality and confident that it won’t degrade the coatings. It isn’t by accident either that the list above is the same order I use in my cleaning process. Cleaning telescope optics has never been easier. It is very important to be sure that any products you use on the telescope optics are of high quality and rated for camera lenses at minimum. If you use products that aren’t suitable, there could be a high risk of damaging the multi-coatings on the lenses or mirrors. If in doubt about a specific product contact the manufacturer.

I hate to say it, but I can’t accept any responsibility if your optics get damaged by following this guide. Sorry, it’s a disclaimer thing. With this out of the way let’s begin!

Rocket Blower

A rocket blower is simply a rubbery ball with a nozzle on it. You squeeze it and air comes out. The beauty of this is in the fine point of the nozzle. A gust of air comes out and removes the larger bits of dust or debris off from the optics before wiping. We want to do this as any small particles could get trapped and then could scratch our lenses up. So blowing them away is an essential part of cleaning telescope optics quickly and safely.

When using the blower, be sure to angle it about 45 degrees where possible to the glass/mirror. Squeeze it firmly and watch the dust blow away. For best results tilt the telescope or camera lens downwards if possible – or put it on your mount to hold it downwards. This lets the dust blow out of any dew shields rather than resting on the lens cell again or getting caught on the shield.

You can get a rocket blower easily from Amazon.

Once you’ve given the optics a good blow over and are sure all the bigger particles are gone, we can move onto the lens pen.

Angle the air blower in relation to the optics

Lens Pen

Lens Pen is a brand name. But the Lens Pen is essentially an ultra-soft brush on one end and a cleaning solution chamois on the other. We don’t use the chamois end for this purpose but I find the brush to be perfect for cleaning telescopes as its so soft and gentle on optics.

After brushing the bigger dirt and dust particles away, go in with the Lens Pen to gently brush any stubborn bits away. Sometimes particles get trapped in joins between lenses and the lens cell. In order to remove them a soft brushing does the job quite nicely. I go over the whole optic from the centre outwards, and then around the cell itself. Flicking away any dirt I come across. Once you’ve brushed the last bits away, I go back in again and hit it with the air blower one final time – with the optics pointing downwards.

Lightly brush any stubborn dirt with the Lens Pen

Next we go onto the actual cleaning itself with the cleaning fluid.

Baader WonderFluid

Baader Wonderfluid is a lens cleaning solution that is absolutely suitable for use with telescope optics. I wish I could tell you exactly what’s in it but I don’t know. If I did I’d probably manufacture my own since it’s absolutely amazing.

Use the Wonderfluid with a nice clean microfibre cloth. Be sure the microfibre cloth is a lint-free version or else you’ll fight a losing battle with lint on your optics!

When using the cloth and fluid be sure to spray the solution onto the cloth. Do not spray directly onto the optics as  speckles could appear and the solution get trapped in joints.

Don’t spray the solution directly onto the optics

After spraying onto the cloth, wipe gently in a circular motion. Do not scrub in any way at all. If there’s stubborn stains or marks on the optics then send it to a professional. When you’ve cleaned the middle move to the outer parts. Cleaning telescope optics this way makes sure the centre is the cleanest. This is the best bit of glass in refractors after all. Then wipe around the lens cell. Repeat this step if needed. After the cleaning, I take a dry part of the cloth and give it a gentle dry wipe down to remove excess cleaner.

Gently wipe and don’t scrub the optics when cleaning

You can find Baader Wonderfluid at First Light Optics.

That’s it! Your optics should now be clean and ready for more astrophotography. I have a video demonstrating each step on YouTube that can be found below.

Before Cleaning
After cleaning

Clear skies everyone. Keep looking up and keep them cameras clicking. I’ll see you in the next one.

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