Cyberstalking - what to do?

Above all, keep all emails and messages - this is a necessary proof, if you choose to report the matter to the police. Do not react. Do not reply to messages even if you are very nervous. Your reaction to persecutors will encourage them to maintain contact with you. It does not matter what you write - it is important that you write at all. More information: cyberstalking - next steps.

Autofocus tracking

Autofocus tracking, tracking it in English autofocus, autofocus and provides a predictiveautofocus. The action of this type of focus in the model Canon EOS-1D Mark IV is a verycomplicated description can be postudiować in this document called the White Paper,of course, English. In our FOTOPORADNIKU let us quote a simplified description of how such a system. That track is a continuous course focusing on a moving object, which is approaching ormoving away from the lens. The points can describe it anyway.

- Camera control program forograficznym "fishes out from the frame a distinctive objectwhich" nacelowaliśmy "our camera. Let this object changes the distance from the camera, which is approaching or moving away from us.
- The program sets the lens so that the image of the object was sharp. This takes about 1 / 100 sec lens settings are stored.
- After a short time as possible (say, 0.05 s) the program re-focusing. The new settingsare stored lens too. The program compares both the lens settings and their values ​​are determined direction of movement of the object and its speed to the camera.
- Press the shutter button to take a picture. The program knows the time of pressing theshutter button until it opened and already knowing the speed and direction of thephotographed object, the program sets the lens so that the image of the object when theshutter speed was sharp.

Multi-point AF

Image produced by the lens is projected, through the arrangement of mirrors, an additional sensor (or several dies) dedicated to focusing. On this matrix are separate areas are arranged so as to cover the entire frame "seen" to postpone the lens.Depending on the sophistication of a digital camera model, these areas can be from several to several dozen. Canon EOS-1D Mark IV is the 45 Each of these areas, popularly known as the point, though this is an area of ​​specific dimensions, serves to focus on him for a portion of the projected image.Focusing is based on such a draw position of the moving lens in the lens to get the greatest contrast. In contrast, a simple apparatus is selected relative vertical edges visible in the frame. Hence, known fault CDs that can not set the focus to the boat on the water, where lines of different areas of the frame are horizontal contrast. In the case of the EOS-1D Mark IV, but many other SLR cameras and the contrast is determined by the vertical and horizontal lines. Called a "cross" area. Of the 45 areas the designation field 39 is a cross areas. Focus is on
capturing an image incident on a point (area) measurementsetting the contrast for the image, which is part of the whole frame projected on the main matrixadjustment of moving lens elementsdetermine whether the contrast has improved or deterioratedwhere the contrast has improved, rules, setting the lens is repeated in the same directionif the contrast worsened, adjust the lens is "the opposite" direction.this method, step by step, we select the greatest contrast, namely setting the lens gives the best focus for the objects seen in the measuring area.Such wyzaczenie focus requires intensive computation and high-speed transfers of lenses in the lens. Calculation of designating a separate processor performs the focus, in case of the EOS-1D Mark IV is 40 MHz, 32-bit RISC on the structure. These calculations are spomagane by the main camera processor - 40 MHz, 32-bit RISC too.

Describing the role of the pentaprism in the DSLR mentioned a total internal reflection of light. We explain this phenomenon accessibly as possible. Let shown here is a cross sectional drawing of an aquarium filled with water. From the bottom of the aquariumthrow a beam of light toward the surface. The direction of the beam determines the angle between the normal (perpendicular) to the water surface and the radius. This angle is called the angle of incidence at the border facilities (water and air).

For small angles of incidence, such as the angle marked in blue, light comes out of thewater and continues through the air.
For a certain angle, called for the border (marked in red), the beam will not go out of the water and "slides" over the surface,
For angles of incidence greater than the critical angle the light reflected from the surface of the water and returns to it. Reflection is completely lossless, ie there is no loss of energy. Hence the name of total internal reflection

This phenomenon occurs whenever the light goes from the center of the denser (with higher refractive index) to the rarer and therefore such

- from water to air

- glass into the air

The phenomenon of internal reflection całkowitegoo is the basis for the construction of fiber optics. In a thin rod of glass or transparent plastic light can travel without any loss of energy very long distance, bouncing off the walls in succession from the bar.

In each SLR, a camera with interchangeable lenses and a mirror directing light rays to the optical viewfinder, there is a pentagonal prism. The prism is used to direct light raysreflected from the mirror to the eye of the photographer. Schematic of light rays in theSLR, is shown in the accompanying drawings.

Structure and elements of an SLR

The SLR camera with a specific structure, so it will devote a separate chapter. Canon has released a document describing very precisely DSLR EOS-1D Mark IV. This is a pdf document larger than 7 MB, so when the first download should be saved to disk for looking into it does not require multiple downloads from the network. This is called the white paper, this term means an official document that explains very accurately describing a problem or a product. In other words, this is a very accurate description of the parameters and rules of operation of the camera. The document has 123 pages and contains many photos, diagrams and charts explaining the operation of the different elements of this camera. Since the Canon EOS-1D Mark IV is currently one of the most advanced models of digital photography apartów SLR class, we use the information contained in this "White Paper" for explanations of the workings of many elements of this type of camera. The best solution is studying the original document, but it is in English and not everyone can handle and understand some subtleties of language. We will not explain it dokmentu, because you must have permission from the copyright holder and only on the basis of the principles we describe the basic elements of an advanced SLR, popularly called as cameras with interchangeable lenses and a movable mirror directing the image from the lens to the viewfinder. Studying the various paragraphs of this chapter should have opened the original document that you can quickly look at the drawing, or diagram illustrating the described problem.

How does a three-dimensional display work?

Built-in screen works in a similar way as already known in the nineteenth centuryfotoplastykony. Each eye receives slightly shifted image that the brain is connected to athree-dimensional object. The problem was, however, the separation of the two versions of a photo or video. Applied to the sets of lenses, or two-color or polarized glasses. All solutions have the same drawback: the use of additional equipment required for viewingthree-dimensional images.

The three-dimensional camera for photography presented by Fujifilm is not necessary.The display is designed so that if you look in front of him, the two eyes may be routeddifferently image. The same works for digital photo frame, you can buy the kit. There is also provided to enjoy the 3D image viewing photos at the right angle and fixeddistance.