Select your language


    It took a long time to improve the production of my optics to offer a broad range of different mirrors now. My main interest is on parabolic primary mirrors for Newtonian telescopes. I also work on flats, spherical, ellipsoid mirrors (e.g. for Dall-Kirkham-telescopes), or hyperbolic optics (e.g. for Ritchey-Chrétien-telescopes). Since the latter could only be realized in close coordination with the customer, please contact me to express your expectations and the purpose of the mirror.

    Please find a table with my usual and standard sizes of common primary mirrors for Newtonian telescopes below. In addition to my standard sizes I can realize any other size from 12’’ to 32’’, any focal ratio from f/2.7 to f/∞, any substrate thickness from 21 to 47 mm. As focal lengths of more than 3200 mm require a larger effort, please ask explicitly for conditions.

    Usually I use Schott Borofloat 33 or a substrate with equal physical properties. Borofloat 33 is established as best substrate for the sizes listed above. Any other kind of glass should be provided by the client.
    If you would like to use glass ceramics instead of borosilicate glass because of its low thermal expansion coefficient, please bear in mind: Small and medium size mirrors are not limited by deformation of the surface under changing temperature, but by turbulence immediately in front of the mirror’s surface. This turbulence is fanned by the great thermal mass of the primary mirror and is maintained by the falling temperature during the night. Actually Zerodur has this turbulence in the same degree as any other glass of this dimension. What initially sounds advantageous – no thermal expansion of Zerodur – is done to naught in practice by the far more harmful releasing heat in form of turbulences because of the primary mirror as heat reservoir. As top priority, a mirror as thin as possible should be chosen. Only then you should think about employing a better substrate  quality than borosilicate glass provides.

    Please note: Details of focal lengths and focal ratios are approximate figures! Usually my optics have a scattering in the focal length of up to +-3%. A mirror having a desired focal length of 2000mm actually receives a focal length between 1940mm and 2060mm. Of course a lower tolerance (down to +-1%) is possible, but this must necessarily be settled in advance. The average surcharge on the prices listed below for smaller focal length tolerances will be between 5% and 15%.

    Which quality can be expected?

      f/5 f/4,5 f/4 f/3,5 f/3
    Ø355mm 0,9 0,9 0,9 0,9 0,85
    Ø400mm 0,9 0,9 0,9 0,9 0,85
    Ø460mm 0,9 0,9 0,9 0,85 0,85
    Ø535mm 0,9 0,9 0,9 0,85 0,8
    Ø600mm 0,9 0,85 0,85 0,8 0,8
    Ø710mm 0,9 0,8 0,8 0,8 on demand
    Ø810mm 0,9 0,8 0,8 0,75 on demand

     

     

     

     

     

     

     


    The table above gives an overview of the minimum Strehl value guaranteed by me, depending on the diameter and the aperture ratio. Basically, this is the minimum accuracy which is usually significantly exceeded. In this context please note my Examples-page and here I describe the measurement method in more detail.
    If you have
    specific requirements, please do not hesitate to contact me.

    You are looking for the greatest possible transparency when buying your telescope optics?

           

    I enclose a CD to every mirror I deliver, containing the complete interferometric final evaluation. This CD contains every used interferogram of all measurement positions, and all software evaluations. You can also find a Quick Start Guide, which allows you to self-evaluate the interferograms.
    A serial number is engraved on the back side of every mirror. This serial number
    can be found as watermark on all enclosed interferometric single shots, so an unambiguous assignment of evaluation and the optics delivered is guaranteed.

                

         Standard price list for Newton-parabolic mirrors of Schott Borofloat or Supremax

    Diameter

    focal ratio

    edge thickness

    price (€)

    355mm / approx. 14"

    f/3.0

    25mm

    3325

    355mm / approx. 14"

    f/3.5

    25mm

    2850

    355mm / approx. 14"

    f/4

    25mm

    2450

    355mm / approx. 14"

    f/4.5

    25mm

    2350

    355mm / approx. 14"

    f/5

    25mm

    2200


    400mm / approx. 16"


    f/3.0


    25mm


    4300

    400mm / approx. 16"

    f/3.5

    25mm

    3675

    400mm / approx. 16"

    f/4

    25mm

    3150

    400mm / approx. 16"

    f/4.5

    25mm

    2875

    400mm / approx. 16"

    f/5

    25mm

    2700


    460mm / approx. 18"


    f/3.0


    25mm


    5900

    460mm / approx. 18"

    f/3.5

    25mm

    5100

    460mm / approx. 18"

    f/4

    25mm

    4450

    460mm / approx. 18"

    f/4.5

    25mm

    4100

    460mm / approx. 18"

    f/5

    25mm

    3950


    535mm / approx. 21"


    f/3.0


    31mm


    on demand

    535mm / approx. 21"

    f/3.5

    31mm

    6600

    535mm / approx. 21"

    f/4

    31mm

    5700

    535mm / approx. 21"

    f/4.5

    31mm

    5100

    535mm / approx. 21"

    f/5

    31mm

    4800


    600mm / approx. 23.5"

     
    f/3.0


    34mm


    on demand

    600mm / approx. 23.5"

    f/3.5

    34mm

    on demand

    600mm / approx. 23.5"

    f/4

    34mm

    7950

    600mm / approx. 23.5"

    f/4.5

    34mm

    7550


    710mm / approx. 28"

     
    on demand


    on demand

     
    on demand


    810mm / approx. 32"

     
    on demand


    on demand


    on demand

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

    The prices are final prices for private customers including 19% VAT. They include further

    • 92% or better aluminum coating with protection layer
    • center mark for laser adjustment
    • interferometric evaluation on CD
    • stable packaging
    • shipping (only valid for shipping in Germany. The carriage charges for overseas will be calculated and added upon receipt of order; charges depend on weight, size of parcel and delivery location).

    Please ask for current delivery times. For precise information please add details regarding the desired diameter, focal ratio and material thickness to your request.
    Please note: The ordering procedure of both the glass substrate and the mirror coating will vary by several weeks. My primary goal is to provide a mirror which you will enjoy for many years. The manufacture of precision optics is a complex process. Thus you cannot predict the exact labor input nor quantify precisely the time necessary. This is why any information about delivery time will be estimated to the best of my knowledge and is not binding. For general information about ordering, purchase, and delivery please check my Terms & Conditions.

    We use cookies on our website. Some of them are essential for the operation of the site, while others help us to improve this site and the user experience (tracking cookies). You can decide for yourself whether you want to allow cookies or not. Please note that if you reject them, you may not be able to use all the functionalities of the site.