Five principles of using the zoom telescope lens

Five principles of using the zoom telescope lens

1. familiar with the zoom lens of the zoom telescope lens, zoom and focus are adjusted by two rings. Now most of the zoom lenses have been changed to single loop control, which is characterized by changing the focal length by pushing and pulling the lens before and after the lens. Therefore, for the photographers who have just bought a new mirror, we should be familiar with and remember the direction of the zoom and the left and right position of the focus, so as to avoid the slight rotation of the adjusting ring when the focus is focused. This is why many more conservative photographers prefer to use the old double ring zoom lens.

2. when using the zoom lens with the long focus distance, the correct focus method is to use the long focal distance to the focus first, then choose the right focal length, because the image of the subject is the largest and the depth of field is the smallest at the long focal distance, which facilitates accurate focusing. In case of backlight or light complexity, it also helps to select the appropriate local photometry without having to approach the subject to measure the light. In regular shooting, a zoom lens with a medium focal length or a long focal length is often used as a focus, focusing and measuring with the longest focal length, and choosing the ideal focal length after the exposure is locked, so that there is no need to move back and forth.

3. make more attempts at each focal length

Although most photographers are very concerned about the zoom problem of zoom lenses, they are often used most often when they are used in specific use, and some even treat them as a fixed focus lens. In fact, when you try to use the other focal length to get a very different picture, you will find the zoom lens as a variable scene tool, with a considerable potential.

4. properly use the support when using a zoom lens with a focal length of 200mm or longer focal length, the lens should be fixed on the support such as the three foot frame to ensure the stability of the shooting.

5. add a distance mirror to use a very long focal length, and spend very little money on a 2 doubling lens, and you can immediately turn your 70 - 210mm lens into a 140-420mm ultra - focus zoom lens, a 3 doubling lens that can reach 210--630mm, making your lens into the ranks of the astronomical telescope immediately. The cost, however, will be the loss of aperture progression and the clarity of photographs. For example, the zoom lens of a F4 plus 2 multiplier mirrors will lose 2 level to F8, and the maximum aperture will become F11 after adding 3 multiplier lenses. As you know, the best solution to the lens should be to choose the aperture which is 2 degrees smaller than the maximum aperture. Therefore, when adding the distance mirror, we must consider the use of high-speed film and three tripod, and at the same time, the subject is still at rest.