It is all about Glass: Lens Coating and Optical Design

Lens Coating and Optical Design

One of the reasons to purchase a Schmidt & Bender riflescope is because of its outstanding optical quality. This is often harder to recognize and it often takes an eye-opening experience to be able to distinguish between good and a poor image quality. The greatest disadvantage is you are negatively affected by poor image quality even if you are not consciously aware of it. Discover what should not remain a secret: the essentials of high quality Schmidt & Bender optics.


Lens Coating

Schmidt & Bender lens coatings adhere to the highest technical standards. Nothing less is appropriate in order to fulfill our demands on image quality and light transmission. Our lens coating is a well composed combination of thin layers of dielectric and metallic oxides. These are mandatory in order to enhance the optical performance since every single lens surface within the riflescope reflects and refracts light. All reflections will cause false-light and less light transmission which will result in an imperfect image quality. Poor image quality has many negative effects such as: eye exhaustion, poor low-light transmission and reduced target recognition and identification. Schmidt & Bender riflescopes distinguish themselves from others through the careful selection of high-quality glass material, combinations of highly refractive glass and SCHOTT HT glass. Schmidt & Bender carefully inspects every lens and optical assembly at each production step to ensure they fulfill our requirements. Since our tolerances are very tight we must measure and handpick every single lens. By doing so, we achieve a minimum amount of variation from scope to scope in regard to optical performance.

Lens Coating


Proof of our optical capabilities: Polar T96

4-16x56 Polar T96 checked in a spectrometer

4-16x56 Polar T96 checked in a spectrometer

A good example of our optical capabilities is found in our Polar T96 Series. Schmidt & Bender optimizes the lens coating procedure by using our unique and patented “Smart Coating”. This causes less reflection – even compared to other high transmissive riflescopes – at the interfaces and the light passes “smarter” through the lens system. As a result, more detail recognition and a sharper image is provided by day and night. Schmidt & Bender guarantees that every Polar T96 riflescope has at least 96 % light transmission. We ensure this by measuring every single Polar T96 riflescope during the final inspection on a spectrometer. The Polar T96 is only approved and delivered to our customers if this value is reached or exceeded.


Optical Design

Optical adjustment via a collimator

Optical adjustment via a collimator

With our “True Color” optic design our engineers have developed and patented a crystal clear image quality having its emphasis on transmitting a true color image to the human eye. This is extremely important to hunters and shooters who need to exactly identify their target. Even in our challenging and complex 8x and 9x zoom ratio riflescopes we have achieved a brilliant image quality due to our patented erector tube lens system. Also, we are using special temperature-stable lenses in our objective in order to secure a precise parallax adjustment and to minimize temperature shift. All this is also accompanied by the use of ED (Extra Low Dispersion) glass. The systematic use of this high-performing glass, eliminates chromatic aberrations which results in color fringing. You might have experienced this in other riflescopes when looking at high-contrast edges as it is the case when looking at a target with black colored rings on white background.

Chromatic aberration

The “Made in Germany” manufacturing ensures a tension-free assembly of the lens also taking the tight tolerances and strict quality control into account which makes our riflescopes reliable under harsh recoil in any kind of environmental condition. In the end, every single riflescope is optically adjusted and checked by our well experienced technicians. Seeing is believing!


The twilight factor does not always represent a meaningful information

Beam path through a 3-21x50 Exos

Beam path through a 3-21x50 Exos

Every technical data sheet mentions the so called “twilight factor”. The Twilight factor is a mathematical formula showing how much detail can be theoretically seen in low-light. It is calculated by first multiplying the magnification by the objective lens diameter, and then taking the square root of that product (e. g. for the 8x56 Klassik: √(8x56) = 21.16). The twilight factor improves with an increase of either magnification and objective lens diameter or both. In theory, the higher the twilight number value the better. However, this mathematical formula is not directly related to the quality of the lenses, their coating or the entire optical design. Therefore, it is possible that a mathematical smaller twilight factor optically outperforms a bigger twilight factor due to a superior overall optical design. With this in mind, the twilight factor can only be compared to optical systems of the same quality. It does not represent meaningful information about the optical performance as such.


A Schmidt & Bender 3-12x42 Klassik will most likely have a better low-light performance than a lower quality 3-12x56 although the mathematical twilight factor speaks against it:

Example calculation of twilight factor for 3-12x42 and 3-12x56

The 56 mm objective is superior according to the mathematical twilight factor. But this does not take the special and patented Schmidt & Bender lens coating and optics design into account which provides a superior optical performance.


Find out more about our riflescopes

Hunting Image PM II and Competition Image
Hunting PM II and Competition


Protect your riflescope

Tactical bag with riflescope

High quality optics from Schmidt & Bender deserve special protection. Whether Protective Lens Covers, Tactical Bags or Cleaning Kits: find everything for protection, cleaning and other useful accessories here.




Clean your riflescope

Clean your riflescope

Now you know what is so special about Schmidt & Bender optics. It is very important to keep your high quality optics in good shape. Therefore, we recommend to check out our information of how to clean your riflescope properly.


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