Frame
A frame is each of the images chemically printed on the celluloid strip of the cinematograph or on photographic film.
When a sequence of frames is displayed according to a certain frequency of images per second, it is possible to generate the sensation of movement in the viewer. The formula for this frequency is as follows:
f(fortorgramas)=1/T(s){displaystyle f(pictures)=1/T(s)}
The result of the formula is expressed in frames per second (with abbreviation FPS). The frame rates of some of the more popular systems are as follows:
- Mude cinema: 16-18 frames per second.
- Cinema: 24 FPS.
- Digital cinema: 30 FPS or more.
But these amounts refer to professional environments, because different domestic teams offered and offer the same or other ratios.
In cinema
To see a motion picture requires that the frames be projected at a cadence of 24 per second; thus they produce the illusion of movement. This is because the rapid succession of images blocks the brain's ability to see them as separate photographs. This persistence in vision causes the brain to mix these images giving the sensation of natural movement.
Types of filming
There are two print formats on film and they are known as flat and scope. The difference between the two is easy to appreciate. The two formats are recorded on the tapes themselves, which are thirty-five millimeters. Within each tape, when dividing the 24 frames of a second of filming, it must be measured by leap's, which are the small holes that the tape has on the sides. The leap's are used so that the projector can drag the tape with the image and movement occurs.
The flat format is recorded on the tape but in the time that corresponds to four leaps the image covers two, so that a black space is shown between image and image, allowing that when viewed the frame without movement the image appears clear and of proportionate size, but when it is projected it appears on the screen as a square image.
The scope format is more distorted in the non-motion frame, since the image that is recorded in the frame has less space between one and the other. The image of this type of format is very close together and looks elongated, and when projected the image is seen in a rectangular shape in movie theaters.
Size of a frame
The size of a film retis frame varies depending on the format of the film. In the smaller 8mm hobbyist format, it is roughly 4.8 × 3.5mm. Whereas in the IMAX format it is as big as 69.6 × 48.5 mm. The larger the frame, the sharper the image appears on the projection screen.
In photography
The frames are each of the impressions made on a film by light entering a camera, regulated with a shutter. When the film is developed, the frames can be projected onto paper to obtain a photograph or photo. A photographic image obtained without the use of a camera by placing objects on a photosensitive surface such as photographic film or paper and then exposing them to direct light is also called a frame.
"Frame" versus "picture"
On many occasions the term film frame is confused with the term video frame. Both terms are equivalent, but they are not the same for four reasons:
- The frame is a visible emulsion, either positive or negative, which allows them to identify and even know where to cut with a scissor or similar. For its part, a picture is an electrical signal that can be recorded or not.
- A Table It has no divisions, a Table consists of two fields, the upper and the lower.
- The frames were identified with a number at the foot of it. The paintings tried to do something similar by using metal particles, but with the entrance of the helical tracks their numbering was obtained using a track with time code and not a physical division.
- The number of frames per second was adopted for logistic reasons mainly, when the number of tables per second was for compatibility with the different electrical frequencies. For this reason some duration should be lost when a 24 FPS film was passed on to a video tape in PAL system of 25 frames per second or one of NTSC of almost 30.