PHONE: (02) 9436 4360


Astro Optical Supplies has available to its customers a coating service for primary and secondary telescope mirrors.

Astro utilises its unique High Fidelity Alloy coating to give the sharpest, brightest images. This coating is designed and applied in a way that allows you to get the most out of your telescope.


Coating/Recoating Prices
Secondary Mirrors (major axis)    
Up to 66mm $55
67mm to 90mm $77
Primary Mirrors (diameter)  
Up to 115mm (4.5") $99
116mm - 150mm (6") $115
151mm - 200mm (8") $165
201mm - 250mm (10") $220
251mm - 318mm (12.5") $295
All prices are in $AUD and include GST and removal of old coatings.

Under normal circumstances the coatings will give excellent results for up to 10 years. Nearly all reflecting telescope sytems will require a recoat after this amount of time.

How can I tell if my mirror requires a recoat?

Sometimes it can be difficult to tell whether a mirror needs a recoat without another telescope mirror to compare it with. Try testing your telescope alongside another new or recently recoated telescope with the same eyepiece.

If you notice a yellowing of the image or loss of definition as compared to the other similar sized telescope then the mirror most likely needs to be cleaned and/or recoated.

A good indoor test that can be easily performed is to hold the mirror (be careful with large mirrors) up to a clear 60-100W light globe and look through it from behind. If you can see the filament of the globe through the coating then the mirror definitely needs a recoat.

Cleaning of mirrors should be done with extreme caution, otherwise removal of the coating can occur. If there is only a small amount of dust on the mirror then it is best left uncleaned. A little bit of dust will do less damage than a poorly executed clean.

How do I send my mirror for recoating?

The best way to transport a mirror is in a sturdy solid box, a few millimeters larger than the mirror (see image 1). Do not wrap the mirror in fabric or similar material.

Securely affix a piece of tapered wood in each corner, and place the mirror face down on the wedges (see image 2).

Screw the lid down with some cardboard or foam between the lid and the back of the mirror to ensure the mirror does not move (see image 3).

Commercially available boxes, ie cake tins, toolboxes, etc can and have been used. Cardboard boxes are not ideal for transporting heavy mirrors.

Call or email Astro if you would like to book your blank or coated mirror in for a clean/recoat.

For mechanical and optical repairs, see our repairs page.

Astro Optical Supplies