How to maintain the SLR camera?

1, lens maintenance and cleaning

The lens is the most critical and fragile part of the camera, so when using the camera at ordinary times, we should pay great attention to the protection of the camera lens, and don't get contaminated with dust easily, and don't let the lens be "dirty" by dirty hands. Only when it is absolutely necessary should we clean the lens. When cleaning, it is best to blow off the dust with a balloon or gently brush it off with a soft brush;

If you encounter stubborn dust, you must gently wipe it with special lens cloth or lens paper. Remember not to use paper that looks soft, such as paper towels, to clean the lens, because these papers all contain wood pulp that is easy to scratch the coating, which will seriously damage the key coating on the camera lens.

2. Protection of LCD screen

Color LCD screen is easily scratched by hard objects, especially the color LCD screen without protective film is more fragile. Any scratch will leave a permanent mark. So when using it, you can consider sticking a protective film on your PDA or mobile phone, which has a very good effect on protecting the color LCD screen.

In addition to preventing scratches, special attention should be paid to avoid the damage of high temperature to color LCD screen. As the temperature rises, the color LCD screen will turn black. After reaching a certain temperature, even if the temperature drops to a normal state, the color LCD screen cannot be restored, causing irreparable losses.

3. Use and maintenance of batteries

Digital cameras are different from traditional cameras. Digital cameras have a great demand for electricity, so SLR cameras generally use nickel-hydrogen batteries or lithium batteries as power sources.

Ni-MH battery will produce memory effect, reducing the total capacity and service life of the battery. As time goes on, the stored charge will be less and less. Therefore, try to use up the power before charging. The memory effect of special lithium battery is almost negligible, so special attention is not needed.

In addition, attention should be paid to maintaining the integrity of the battery insulation. Once the damage is found, stick it with transparent tape. Always check whether the electrode of the battery is oxidized, and wipe it clean if it is slightly oxidized. When serious oxidation or falling off is found, the battery should be replaced immediately to avoid damage to the single-lens reflex camera caused by battery leakage and other faults.

In addition, when the digital camera is not used for a long time, the battery must be removed from the digital camera or charger, completely discharged, and then stored in a dry and cool environment.

4. Travel guarantee

Protect the lens with the lens cover, put small equipment and accessories in the bag and hand, and separate them with certain soft objects to ensure that they will not collide with each other. Especially those easily damaged equipment, should be wrapped in a soft layer.

When flying, the damage degree of metal detector is slightly less than that of baggage detector. If necessary, manual inspection can be required to minimize X-ray damage.

5. Long-term preservation of digital cameras

When the digital camera is not used for a long time, we should pay attention to the maintenance of other parts and accessories besides the important parts such as the body and lens. The camera and holster should be placed separately to prevent the moldy holster from affecting the camera. Parts such as shutter and self-timer that have been tightened in the camera should be loosened to avoid damage caused by fatigue of these parts for a long time.

The lens aperture should be set at the maximum gear and the focusing distance should be set at infinity. If it is a camera with a dual focal length lens or a zoom lens, the extended lens should be retracted to its original position and then put into a storage container that can be kept dry.

Description of extended data camera

1. Coke section

People often ask how many times the lens of a DSLR camera is. Please note that this is an extremely amateur question. When the digital camera was just born, because the focal length of the lens was pitifully small, in order to distinguish it from the focal length of the traditional 135 lens, we only talked about the zoom multiple and didn't talk about the actual focal length, which would make people forget that the focal length was small and the photosensitive area was small, which was actually a distraction.

But DSLR uses the lens of 135 camera, which is usually based on the actual focal length, such as 17-85mm, which means that the zoom range of this lens is17 mm ~ 85 mm.

If you insist on asking how many times the lens is, then this lens is 5 times zoom. The reason why it is unscientific to convert a single-lens reflex camera like this is that since the DSLR can replace the lens, if it is replaced with a lens of 70-200, the zoom factor is less than 3 times, but the base starts from 70mm, which is actually farther than the previous lens with 5 times zoom.

Even for consumer cameras, the final result brought by optical zoom magnification is related to the starting base, and not all the fields of view with the same magnification are the same, so the magnification of consumer cameras is also a vague concept.

2. Original lens and sub-factory lens

Camera manufacturers such as Canon, Nikon and Pentax, which produce DSLR fuselage, are called original lenses in order to correspond to the lenses produced by their DSLR systems. And some professional lens manufacturers provide lenses with different camera interfaces, so that consumers have more choices, such as lenses with interfaces such as Canon, Nikon and Pentax produced by manufacturers such as sigma, tamron and tokina, commonly known as sub-factory lenses.

Of course, it seems inappropriate to refer to these professional lens manufacturers as sub-factories, because many lenses produced by these professional lens manufacturers have the same quality as the original lenses, but the prices are much less than the original lenses, making them the first choice for many photographers who are not well off.

3. The focal length conversion rate

By 20 16, although the photoreceptor size of mainstream DSLR is much larger than that of consumer cameras, it still can't meet the specifications of 135 film (unless it is a full-frame camera). Therefore, if the lens of 135 camera is installed, the imaging range will be different from that of 135 camera, which usually needs to be multiplied by 65438.

For example, Nikon DSLR is equipped with a 50mm lens, and its viewing angle is equivalent to the viewing angle when the focal length is 50 mm×1.5 = 75 mm. However, the optical characteristics of a certain focal length will not change because of the same viewing angle. Even the "equivalent to ××mm~××mm of 135 camera" declared by consumer cameras in the publicity only means that the viewing angle is equivalent, and the optical effect cannot be "equivalent".

Imaging principle

In this system, the unique design of the mirror and prism enables the photographer to directly observe the image passing through the lens from the viewfinder. It can be seen from the structural diagram of a single-lens reflex camera that the light reaches the reflector through the lens and is reflected to the focusing screen above to form an image. Through the eyepiece and pentaprism, we can see the scenery outside in the observation window.

The light passes through the lens and is reflected by the reflector to the frosted viewfinder. Through the convex lens and reflected in the pentaprism, the final image appears in the viewfinder. When the shutter is pressed, the mirror moves in the direction shown by the arrow, and the mirror is lifted, and the image is taken on CCD or CMOS, which is consistent with what is seen on the viewfinder screen.

Compared with paraxial cameras, SLR cameras have the advantage that what you see is what you get, and the imaging angle in the viewfinder is the same as the final film. However, compared with paraxial camera, the back focus of SLR camera lens should be able to image at the focal plane of reflector and photosensitive element at the same time, and false focus must be generated before imaging at the focal plane, which makes the structure of SLR camera optical lens more complicated and larger, and the imaging effect is not as direct and transparent as paraxial camera. At the same time, the volume of the "reflector" should be large.

References:

SLR camera-Baidu Encyclopedia