How to choose a movie

When you buy film for your camera, you have many choices. Products with the word "color" in their names are usually used to take color photos, which you can hold in your hand and watch through reflected light. The negative obtained by photos is exposed in the camera; Those products with the word "chrome" in their names are used to shoot color transparent films (slides) that need to be watched by some kind of projector. In this case, the resulting slide is the actual film exposed in the camera. Film sensitivity A film with ASA (American Standards Institute) or ISO (International Organization for Standardization) rating will indicate its sensitivity. ISO and ASA grades are the same. The following are some of the most commonly used film sensitivities: ISO 100: Suitable for outdoor photography under bright sunlight ISO 200: Suitable for outdoor photography or indoor photography under bright lights ISO 400: Suitable for indoor photography ISO 1000 or 1600: Suitable for indoor photography without flashlights. Once you decide to choose photos or slides, the next factor to decide is film sensitivity. Generally speaking, the relative sensitivity level of the film will be indicated in its name (for example, MYColor Film 200). ISO and ASA sensitivity are usually printed on the box. The higher the number, the faster the film is sensitized, and "faster" means the stronger the sensitivity. When you take pictures of fast moving objects and focus on them, or when you take pictures in a dim environment without additional lighting (such as flash), you need to use fast sensitive film. The disadvantage of using fast photographic film is that larger silver halide particles are needed to enhance the sensitivity. These larger particles can cause spots or "wood grains" on photos, especially when enlarging 35 mm film negatives. Professional photographers can also use a larger negative to reduce the magnification and reduce the wood grain in the photo. The balance between photographic sensitivity and wood grain shape is an inherent feature of traditional photography. Photographic film manufacturers are also constantly improving to achieve high sensitivity and less wood grain. Low-sensitivity film is suitable for portraits. At this time, the target is still, you can control the lighting of the target, and you may want to develop a larger photo from the negative. The finer silver halide particles in these films can produce the best results. Advanced amateur photographers may encounter more film names, such as tungsten balance or sun balance. Tungsten balance film is used for indoor photography, and the main indoor light source comes from the light emitted by tungsten filament bulbs. Because the visible light emitted by electric light bulb is different from sunlight, it is necessary to correct the spectral sensitivity of film to obtain satisfactory photos. This is most important when a transparent film is used.