Prisms and prism types for binoculars
LensesThe use of aspherical lenses leads to a reduction in the overall length of the binoculars and in some cases to a significant reduction in weight. " More info have the property of displaying objects upside down and inverted - therefore the image must be rotated again.
The image generated in this way is PrismsThe different types of DDoptics binoculars Binoculars can be divided into two main types according to their basic construction: Construction with roof prism (different types of construction) or with Porro prism. Both designs have their unique advantages and disadvantages. In principle, Porro and roof prism binoculars can offer the same performance depending on the type of glass (BAK 4, crown glass, etc.), the amount of coating required and the manufacturing quality. The details decide whether they are good binoculars or not. " More info first of all, be straightened up again and displayed on the correct side.
For this purpose, either so-called Porro prisms or Roof prisms used. Porro prisms give the entire binoculars the characteristic Angled shapewhile Roof prisms the binoculars Slim design enable.

Nowadays, for reasons of space, roof edge glazing in modern designs is predominantly Schmidt-Pechan inverted prisms (on the right of the photo) used.
With the DDoptics Nachtfalke binoculars of the HDX series and with the binoculars Pirschler HDX 8×56 For performance reasons, DDoptics relies on Abbe-König prisms (left on the photo). These consist of two parts, which can be cemented together or kept at a small air gap.
In the past, when there were no ultra-modern Prism compensation prisms were available, these prisms always had to be cemented in order to Transmission losses ( approx. 9% ), which result from reflections, must be avoided. In particular, these reflections can enter the image as stray light or ghost images.
Today we work with highest quality multilayer coatings. Thanks to this coating technology, it is possible to optimise the Reflection reduced to below 0.2% can be used. This makes it possible to dispense with the cementing of the prisms, so that an air gap is created between the two glass surfaces, in which DDoptics, for example, inserts a shading diaphragm. The shutter reduces stray light effects and false light.