Lens Converters page 4

What is a front lens?

A front lens consists of a lens that can increase or reduce the focal length to an object. This lens is attached to the front of a lens via the thread. In addition to the option to buy a separate macro- of wide-angle lens, for example, you can also use a front lens. The available front lenses indicate which lenses they are suitable for. Providers such as Fujifilm, Zeiss and Sony offer models for different possibilities.

Changing the focal distance

Depending on the type of attachment lens, the focal distance is reduced or extended. Macro or telephoto photography reduces the focal distance so you can bring objects closer. To achieve the best results, it is important to focus manually, since the autofocus function makes the object less likely to be sharply displayed with a front lens. In photography with a wide-angle or fisheye lens, the focal distance is extended with a front lens. This allows wider images to be captured and maintains the high resolution of your lens. The indication used for front lenses is just like with glasses in + and – (dioptre). The higher the number, the shorter the focal distance, a minus number indicates a longer focal distance.

Stabilise the image

It is important to use a tripod to promote the image stabilisation of front lenses. A tripod or monopod ensures that the influence of vibrations is minimal and also increases the sharpness of the shot. With macro and telephoto photography you have to deal with heavier lenses quite quickly, and it is therefore necessary to have the necessary support.

Combining front lenses

Front lenses can be combined to increase the effect of the intake. However, you run the risk of vignetting. This greatly reduces the brightness in the corners of the shot. The image quality also deteriorates when using multiple front lenses. So always make sure the front lenses work well together, and that there is not too much loss of quality in combination.

Achromatic front lens

An achromatic front lens consists of several layers of glass with which the deviations are colour corrected. With a normal preposition lens, chromatic aberration sometimes occurs. This creates striking colour differences because the light with different wavelengths is not broken in the same way. The achromatic preposition lenses offer higher quality film recordings where colour sifting is kept to a minimum.