The main difference between the roof edge and the Porro system is the roof edge, where one of the reflective surfaces resembles a house roof (see picture below).
In order to be able to recognise details over long distances even in twilight, binoculars with high magnification and corresponding twilight performance (e.g. 10×56 or 8×56) are recommended.
When the reticle is in the 1st focal plane, the reticle simply enlarges with the magnification adjustment.
The reticle in the 2nd focal plane does not simply magnify when looking through the optical sight.
Unfortunately, fine details such as the light unit are often skimped on. And this has far-reaching consequences! Not so with DDoptics.
The dioptre correction on the eyepiece is used to compensate for different visual acuities of the eyes.
