What is a mirror lens?
The mirror lens or catadioptric lens is a telephoto lens that consists of both a lens and a mirror. This combines the refraction of light and reflection, making them particularly suitable for astrophotography. Originally this type of lens was designed 200 years ago for use in lighthouses and microscopes. The curved mirror that this lens has ensures that the mirror lens is much shorter in size than the standard telephoto lens, but also has a number of disadvantages compared to the more expensive telephoto lenses.
The advantages and disadvantages of a mirror lens
When the mirror lenses appeared on the market in the fifties on a large scale, they immediately became famous for their compactness and light construction in comparison with the large and very heavy telephoto lens. Of course, in recent years the telephoto lens has also improved much with regard to weight and size, but the mirror lens still has an advantage in this regard. In addition, they are very handy to use and can therefore be well stabilised by hand. With sufficient light and optimal conditions, manual focusing can produce impressive results. However, with a fixed aperture of 6.3 or 8.0, under dark conditions they lose a considerable amount in quality and have a limited depth of field. Contrast reduction soon occurs due to the mirror system and soon also results in the background looking more blurry. Another limitation of the mirror lens is that it does not have image stabilisation, but it also does not weigh much.
The dominant position of Samyang
The market of the mirror lens has been very limited for years. Whereas in the past it were the large brands Nikon and Canon which sold various lenses of this type, nowadays this is limited to just one brand, the Korean Samyang. This brand offers mirror lenses which are suitable for cameras of various brands.
