product description
Reducers are used to shorten the focal length.
In their simplest form, they are also known as Shapley lenses. The optical performance is very limited and always depends on the telescope used.
Universal reducers, such as the Barlow lens, are not possible and limit the achievable image quality enormously. This means that a reducer is only useful if it has been calculated 100% for the same optics!
So-called universal reducers are always a compromise and do not always bring an improvement. Sometimes a ‘good’ quality is feigned on the basis of a black/white image in order to conceal imaging errors (e.g. colour errors).
