What kinds of filters do astronomical telescopes have and what are their functions?

At present, there are mainly the following filters:

(1) gradient filter

Gradient filters have many colors. If you think the sky is not blue enough, you can use a blue gradient lens to deepen the color of the sky without affecting other parts of the picture. You can also use yellow, orange or red gradient lenses to shoot special colors at sunset. The color change between the colored area and the colorless area of the gradient lens can transition suddenly or gradually, and different color change effects can be obtained. The gradient mirror also includes a medium gray gradient mirror that is not biased to any color. Its main function is to weaken the image brightness of the shot scene without changing the brightness contrast and color contrast of the shot image, and will not affect the color balance of the color sensitive film.

(2) Starlight mirror

This is an interesting filter. Simply put, it is a glass filter with a net-shaped shallow groove on the surface. The starlight mirror will soften the image slightly, and can turn the light source in the picture into many stars, creating a romantic and childlike artistic conception. The spectrum is also decomposed into a laser beam with a flickering central point ray image. There are many types of starlight mirrors according to the different starlight effects, such as four lights and six lights.

(3) Infrared filter

Infrared photography is a relatively different way of shooting, and the images it takes give people a strong shock and make people fondle it. It also plays an important role in public security, archaeology, medicine and other fields. This is also the reason why infrared filters are sought after by camera enthusiasts.

In recent years, with the popularity of home digital cameras, especially after Sony first introduced the night vision function, people began to be interested in infrared and its photography, because CMOS/CCD photosensitive elements used in digital cameras can receive infrared wavelengths. Now we can take infrared photos and dynamic scenes only with infrared filters, and it is more convenient to understand and observe the strange infrared world in a WYSIWYG way! For example, the 58 mm gold combination of IR infrared filters includes an 850NM infrared filter and a 950NM infrared filter. 850NM is suitable for indoor and low light shooting, and 950NM is suitable for outdoor and strong light shooting. Suitable for all 58MM digital cameras, Sony and Panasonic digital cameras have the best effect.

(4) color compensation filter

Color compensation filter is another filter commonly used outdoors, and outdoor photographers often use it to shoot color slides. It finely adjusts and controls the color reproduction of color film, so as to make proper color compensation for the shot picture. Although the color compensation filter is not as attractive as other filters, it is very important.

(5) Color temperature filter

The color temperature correction filter can adjust the color temperature in the light source. Everyone knows that the color temperature of indoor lighting is different from that of outdoor sunlight, and even the color temperature of morning and evening light and the color temperature of noon light in a day are different. If the color temperature can be corrected by a suitable color temperature correction filter, the ideal effect can be obtained.

(6) Soft lens

Sometimes, soft images can create an atmosphere and give people a sense of beauty better than clear images. Soft lens is suitable for portrait shooting and landscape shooting, which can inhibit and beautify the skin, wrinkles or facial defects of the elderly. Soft light mirror can bring you a soft and romantic atmosphere and interpret a gentle theme for you.

(7) Enhanced filter

If you want to enhance the color of the scene, the enhancement filter can help you achieve your goal. Enhanced filters do not produce eye-catching effects like other filters. Generally, it is only used to improve the visual effect and color saturation of warm objects such as red, light red, brownish red and brown in the scene, making them more vivid, rich and intense. Different brands of enhancement filters can highlight different colors.