What are the skills of underwater macro photography?

Lead: Underwater macro photography is not difficult from a technical point of view. Fortunately, with TTL technology, photometry is as easy as eating pie. Moreover, the macro photography technology accumulated, practiced and mastered on land can also be applied to water. Let's talk about the skills of underwater macro photography.

The magnification of macro photography mentioned here is generally from 1: 3 to 1: 1. 1: 3 means that the exposed image on the negative is 3 times smaller than the actual object; And 1: 1 means that the image on the negative is the same size as the actual object. (That is to say, the proportional formula given on the macro lens, the number to the left of the colon represents the image size of the negative, and the number to the right represents the size of the actual subject. For example, when the insect with the actual length of 10mm is photographed with the maximum magnification of 1: 3, the image size formed by the insect on the camera negative or digital photosensitive chip is 3 mm ... when photographed with the macro lens of 1: 1, the negative image size is 10mm).

In order to shoot in a macro range, a special lens and a waterproof lens barrel are used. Generally speaking, a macro lens can focus from infinity to the maximum magnification. In addition, the head (about 50mm lens) can also be combined with the close-up lens. But this kind of connecting ring can't be taken off when diving, so the focus of the lens will be limited to a certain range.

The focal length of the traditional macro lens is generally 50-60 mm, and the macro lens with the focal length of100105 mm or 180/200mm can't give you a larger magnification, but it can shoot a longer distance. Tracking and photographing those swaying fish has obvious advantages, and sometimes it is even a prerequisite.

skill

There is a significant difference between macro and other shooting, that is, the extended lens barrel increases the distance between the lens and the basement membrane, thus greatly weakening the propagation of light. People with TTL function now have an advantage because they don't have to calculate the exposure compensation problem. The sensor installed in front of the film can automatically calculate the loss of light and compensate. It is much more difficult to shoot macro manually. If someone has such enthusiasm to try, they should be prepared for underexposure and take the time to study how to compensate. Focusing is also a problem of macro photography. Entering the macro shooting range, the depth of field will decrease geometrically. Focusing something only a few millimeters at the right distance by manual focusing is really a big challenge, and the result is often very small out of focus, especially in dim light. Practice shows that for beginners of underwater macro photography, relying on autofocus will make better films, because autofocus is faster and more accurate than any human eye. Set the camera at? Servo autofocus? (s file). In this mode, you can ensure that the selected focus is always clear when composing, and press the shutter at the right time! If necessary, gently move the camera back and forth to adjust the focal length.

Exposure; expose

Try to narrow the aperture to make up for the lack of macro depth of field. Macro lenses produced by big factories are almost all f32 apertures. In addition, because the long lens barrel of the macro lens increases the distance between the lens and the negative film and increases the loss of light, it is obviously necessary to compensate a lot of light to achieve correct exposure. Shorter shooting distance can make up for this. It is more suitable to use 100ASA(ISO 100) film, 50/60mm macro lens and flash with flash index of 1 1. When shooting with 100mm/ 105mm macro head, the flash output should be doubled. This can be achieved by using two lamps. When shooting with a lens with a longer focal length, you should even consider using the first Three Lamps District. The same method applies to people who use it? Range finder? Situation. The rangefinder can double the focal length and magnification of the lens to 2: 1. In actual shooting, using two or three small macro flash lamps is far better than using an industrial-grade strong flash lamp. The special macro flash can provide a suitable color temperature of 5600K, so the color reproduction is good and easy to carry and control. Wide-angle flash is used for long-distance lighting, its color temperature is relatively low, and its color tone will be orange or red.

Flash and its position

The traditional macro lighting method is front lighting. Putting the flash directly above the camera can ensure that the subject can have good lighting in most cases. In some cases, front lighting and side lighting are combined to emphasize some specific functions. For example, the side light can emphasize the gills of sea rabbits, and the front top light can highlight the spikes on the back of stone fish. In order to make the position of the lamp convenient and flexible, the flash should be as small as possible and installed on the lamp arm composed of two short arms. Just as important as flash lighting is to highlight the main body. What a terrible thing if a macro photo keeps the audience from finding out which one is the subject for a long time. Therefore, it is very important to separate the main features from the foreground and background. You will take a photo of an anemone growing in the embrace of the blue sea with a unique keen eye, which is independent of the rock (in order to make the background appear blue, aim the lens at the water surface and use a slow shutter speed of115 to 1/8 seconds).

Matters needing attention

Even when shooting macro shots, environmentally conscious underwater photographers should avoid touching coral reefs or rocks. Pinch a corner of the coral gently with two fingertips, and the rest of the body hovers in the water, which should be enough to support and control the camera. Therefore, good diving technology and neutral control are prerequisites. Good underwater behavior is not only good for the environment, but also makes submarine guides like you. Remember, diving guides have their own secret locations. Those diving spots are not abused places. Diving guides only show people they trust.