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Products We Provide
We have developed a breakthrough patent pending lightweight sandwich mirrors, which
are a cost effective alternative, not just to other lightweight mirrors, but also to all solid
mirrors available on the market.
Currently, our lightweight sandwich mirrors are available from 8” to 40” in diameter.
Please contact us for larger mirrors.
You are welcome to visit our eBay store:
http://stores.ebay.com/hubbleoptics
Why Lightweight Sandwich Mirrors?
Telescope mirrors are manufactured in a strictly controlled temperature and humidity
environment. In particular, each mirror is carefully measured after it has reached
equilibrium in our laboratory. This is not the environment that your mirror will be used in.
While cooling, gradients in the mirror will cause deformation of the surface, and the
aberrations induced by these gradients will be proportional to the CTE of the substrate.
These gradient-induced aberrations die out as the mirror cools and equilibrates.
We have developed a breakthrough patent pending lightweight sandwich mirrors, which
are a cost effective alternative, not just to other lightweight mirrors, but also to all solid
mirrors available on the market.
Currently, our lightweight sandwich mirrors are available from 8” to 40” in diameter.
Please contact us for larger mirrors.
You are welcome to visit our eBay store:
http://stores.ebay.com/hubbleoptics
Why Lightweight Sandwich Mirrors?
Telescope mirrors are manufactured in a strictly controlled temperature and humidity
environment. In particular, each mirror is carefully measured after it has reached
equilibrium in our laboratory. This is not the environment that your mirror will be used in.
While cooling, gradients in the mirror will cause deformation of the surface, and the
aberrations induced by these gradients will be proportional to the CTE of the substrate.
These gradient-induced aberrations die out as the mirror cools and equilibrates.
After years of research, ASTS concluded that "thinner substrates dramatically reduce the
thermal time lag", Technical Note #0028 by Nathan Dalrymple. For any mirror, cross
sectional thickness of the glass is the primary factor in determining the thermal time
constant. As a rule of thumb, the magnitude of the thermal time constant is roughly
proportional to the square of the thickness of the glass. So, with ever-changing
temperatures during observing or imaging, your full thickness mirror may never reach
equilibrium, and never reach its full optical potential. This is one of the major reasons
why our lightweight-sandwich mirror has superior optical performance in real world
situations, even without an active cooling system. (Active cooling systems, such as fans,
introduce their own serious problems, such as micro vibration, which can seriously
degrade the image quality if not done correctly.) Our mirrors reach equilibrium extremely
fast, and without aid.
So, with our lightweight-sandwich mirror, what is measured in the laboratory is observed
in the field.
Hubble Optics Lightweight Sandwich Key Features:
The Hubble Optics Plate Glass Lightweight Sandwich Mirror Price:
OD Thickness (mm) Price (Plate Glass, F/5)
14.0" ~49 $1,100
16.0" ~53 $1,500
18.0" ~53 $1,900
20.0" ~53 $2,400
22.0" ~57 $3,000
23.0" ~57 $3,350
24.0" ~79 $3,750
28.0" ~79 $5,800
30.0" ~79 $7,250
32.0" ~87 $9,100
36.0" ~87 $14,000
Strehl Ratio >= 0.95
thermal time lag", Technical Note #0028 by Nathan Dalrymple. For any mirror, cross
sectional thickness of the glass is the primary factor in determining the thermal time
constant. As a rule of thumb, the magnitude of the thermal time constant is roughly
proportional to the square of the thickness of the glass. So, with ever-changing
temperatures during observing or imaging, your full thickness mirror may never reach
equilibrium, and never reach its full optical potential. This is one of the major reasons
why our lightweight-sandwich mirror has superior optical performance in real world
situations, even without an active cooling system. (Active cooling systems, such as fans,
introduce their own serious problems, such as micro vibration, which can seriously
degrade the image quality if not done correctly.) Our mirrors reach equilibrium extremely
fast, and without aid.
So, with our lightweight-sandwich mirror, what is measured in the laboratory is observed
in the field.
Hubble Optics Lightweight Sandwich Key Features:
 | Thermal and Structural optimized open core, and dynamically stable closed back | |
| design | ||
| Rapid Thermal Response: cools down about 10 times faster for mirrors up to | |
| 23", and about 20 times faster for mirrors between 24"-36",f than a solid mirror of equal thickness. | ||
| Outperform both conventional solid and closed cell lightweight mirrors in term of | |
| image quality in the real world observation | ||
| Simple Floatation Mounting | |
| Lighter than the solid mirrors (with weight saving about 20% for mirrors up to | |
| 23", and about 40% for mirror larger than 23" comparing with the solid mirrors of equal thickness) | ||
| Cost competitive and unprecedented price/performance ratio |
The Hubble Optics Plate Glass Lightweight Sandwich Mirror Price:
OD Thickness (mm) Price (Plate Glass, F/5)
14.0" ~49 $1,100
16.0" ~53 $1,500
18.0" ~53 $1,900
20.0" ~53 $2,400
22.0" ~57 $3,000
23.0" ~57 $3,350
24.0" ~79 $3,750
28.0" ~79 $5,800
30.0" ~79 $7,250
32.0" ~87 $9,100
36.0" ~87 $14,000
Strehl Ratio >= 0.95
The main problem is not the aberrations
due to deformation, but the layer of warm
air in front of the primary mirror. This layer
of warm air is the main cause of the
image distortion called "mirror seeing",
which is caused by the non-uniform index
of diffraction in the cooler air over the
warm mirror surface. No mirror,
regardless of the type of glass used, will
perform adequately until the mirror is
close to the temperature of the ambient
air. This occurs when the temperature
difference between glass and air is less
than one degree centigrade (°C), and best
performance is achieved when this
difference is less than 0.2 °C.
due to deformation, but the layer of warm
air in front of the primary mirror. This layer
of warm air is the main cause of the
image distortion called "mirror seeing",
which is caused by the non-uniform index
of diffraction in the cooler air over the
warm mirror surface. No mirror,
regardless of the type of glass used, will
perform adequately until the mirror is
close to the temperature of the ambient
air. This occurs when the temperature
difference between glass and air is less
than one degree centigrade (°C), and best
performance is achieved when this
difference is less than 0.2 °C.
Therefore, the goal is to bring the
temperature of the mirror to within 0.2 °C
of the ambient air temperature as quickly
as possible. This will greatly reduce
image distortion due to mirror seeing.
This is why all large professional mirrors,
regardless of the type of glass used,
employ complicated cooling systems to
cool the primary mirror. For example, the
Advanced Technology Solar Telescope
(ATST) 4.24-meter primary mirror uses a
jet cooling system.
temperature of the mirror to within 0.2 °C
of the ambient air temperature as quickly
as possible. This will greatly reduce
image distortion due to mirror seeing.
This is why all large professional mirrors,
regardless of the type of glass used,
employ complicated cooling systems to
cool the primary mirror. For example, the
Advanced Technology Solar Telescope
(ATST) 4.24-meter primary mirror uses a
jet cooling system.