Optics

Mirror is the most important part of the telescope. Even the best construction made with perfect accuracy will not give satisfactory images if the optics are poor. It’s the heart and soul of the telescope. At Taurus, we know this very well, so we equip our telescopes with the highest quality, precision, hand-figured mirrors. Our experienced staff repeatedly examine and correct the optical surface of each mirror during the entire production process until it reaches the perfect parabola shape with an accuracy of 0.00005 mm. Creating the perfect mirror requires a suitable substrate. For the production of the Standard series mirrors, we use borosilicate glass substrates. The reflecting layers form aluminum protected with SiO2 which guarantees the highest durability and efficiency of 93%.

For the most demanding observers, we offer a series of Professional mirrors manufactured from carefully annealed SUPERMAX®33 glass (equivalent to the popular Pyrex glass) manufactured by SCHOTT in Germany. This material has a very low factor of thermal expansion of 3.25 x 10-6 K-1 (like pyrex), and high rigidity. As a result, surface deformations are minimal and allow observation to be started 2 times faster compared to BK7 mass-produced mirrors. All Professional mirrors have advanced metallic-dielectric coatings with increased efficiency of up to 96% in the visible spectrum. They have a unique serial number and quality certificate confirmed by test results.

Main mirror parameters:

Focal length
(mm)
Diameter
(mm ±2)
Glass type Reflectivity Quality
(P-V)
12″ F/5
Standard
1500 302 borosilicate 93% 1/4
12″ F/5
Professional
1500 302 Supremax 96% 1/8
Certificate
14″ F/4.8
Standard
1700 353 borosilicate 93% 1/4
14″ 4.8
Professional
1700 353 Supremax 96% 1/8
Certificate
16″ F/4.5
Standard
1800 404 borosilicate 93% 1/4
16″ F/4.5
Professional
1800 404 Supremax 96% 1/8
Certificate
20″ F/4.2
Standard
2150 506 borosilicate 93% 1/4
20″ F/4.2
Professional
2150 506 Supremax 96% 1/8
Certificate

All parabolic mirrors have a centrally located marker that makes collimation easier. The edges are finished at 45º angle. In addition, the center with the offset is marked on the secondary mirror.

On request, we manufacture Professional 1/8 P-V mirrors from FLOAT glass. This is an attractive alternative to Supremax. Glass production process is more complex and time-consuming which discourages many manufacturers, however the low price of ingredients make float glass much cheaper and worth attention. The float glass is less resistant to change of temperatures which results in more extensive deformations. When the mirror reaches temperature of its surroundings it provides images identical to those provided by supremax type glass.

Our mirrors have top quality metalic-dielectric coatings made of aluminium secured with SiO2. Applied in vacuum chamber with an electron gun. Physical vapour deposition (PVD) method allows material to be distributed evenly and very precisely over the mirror’s surface. Thanks to the above the real surface performance is as high as 96% which is confirmed by spectrometer measurements. As a comparison: a typical mirror protected with silicon oxide has reflectivity index at level of 88-89%.

We also offer services of professional steaming of new mirrors and renewal of old mirror coatings. Maximum mirror’s diameter possible for the above is 1100 mm. See Coating page for more info


You have not found in our offer the mirror of your interest? Please contact us. We fulfil individual commencements. Mirrors with diameters 10” – 25”.