Digital camera literacy dictionary has recently been a lot of new buying machines asked a lot about how to use digital cameras, and some problems are generally existed, and some problems seem to have a certain representation, especially for buying parallel The color friends who move immediately may have more problems, so they want to make a solution set for a common problem. Some of the contents from the "Digital Imaging FAQ" book.
How do I test the bad point and noise of digital cameras?
If the image forming element of the digital camera CCD is corrupted, it is not possible to imaging (photosensitive), that is, a dead pixel. The photosensitive elements have thermal stability, and the temperature is increased, and the noise signal is too strong, and a variegated spot is formed on the screen, which is the noise (HOT PIEL). You can use specialized tool software deadpixeltest to test bad points and noise, usually take a few photos with different shutter speeds (such as 1/30 seconds, 1 second, etc.). Theoretically, the image should be pure black. If there is a spot, it is a bad point and noise. If each shoot appears in the fixed position of the photo, no matter how the exposure combination and how the sensitivity (ISO) always exists, then Bad point. Noise generally increases with the extension of the exposure time, the increase in sensitivity, an increase in the temperature of the camera temperature, and the general position is not fixed. Millions of pixel digital cameras have one or two bad points, and the impact on imaging is not big. It should be noted that the LCD of a digital camera may also have a bad point.
~ Does the digital camera imaging element CCD have bad points?
At present, some advanced digital cameras have a function, such as Nikon5700, similar to formatting the CCD, can mark the bad point mark out to remoster. In fact, the camera manufacturer's factory and repaired high-pixel cameras are also using such software algorithms to block bad, from this perspective, some bad cameras can be repaired, unless the bad point is too serious. Replace the hardware.
~ What does A, S, M, P on the turntable do?
P-program automatic exposure, as the name suggests that DC automatically determines the corresponding aperture and shutter speed according to the test light to achieve the correct exposure. There is often a "scenario mode" or "simple mode" and P-files, which are automatically exposed. It is generally automatic exposure, and you can also adjust white balance, exposure compensation, etc.
A-aperture priority automatic exposure, that is, you can first determine a aperture, then DC automatically adjusts the corresponding shutter speed according to the measurement to achieve the correct exposure. For example, commonly used is a fixed F2.0 large aperture, and then use the big zoom to blurred the background.
The S-shutter is prioritized automatically, that is, you first determine a shutter speed, then DC automatically adjusts the corresponding aperture according to the metering to achieve the correct exposure. Many cameras to use the slow door to be used when the camera is shooting, such as 1 to 30 seconds, etc., the exposure, which needs to be transferred to this mode.
M- all manual mode, the aperture and shutter need you to set it yourself. It is usually necessary to use when shooting scenes and darkness differences are huge, such as snow, night scenes, etc., because automatic testing may be invalid at this time.
~ Where is the difference between optical zoom and digital zoom?
Simply put, the former is hardware, the latter is the software interpolation simulation. When the DC is zoomed, the general graph show two sections, the previous paragraph is optical zoom, when the zoom entry is used, the digital zoom is used, and the image effect obtained by the general digital zoom is significantly higher than the optical zoom. However, when there is not enough zoom, you can try to use the following method to increase the quality of the picture, one is to use digital zoom when the sunny day and the air quality is better, one is for some machines. You can try to use a smaller photo size, such as S602 maximum photo size is 6 million pixels, you can use 3 million pixels and then use digital zoom, more images you get directly with 6 million pixels to digital zoom. . There are also some of the quality of its digital zoom itself, which is of course better. ~ Why is the minimum aperture of the digital camera is not small enough, very little conventional camera F11, F16 or even F22 aperture value?
Most non-professional digital camera lens is short (the lens is very close to the CCD), the physical diameter is small, and the physical aperture of the photoelectric in F8 has been small. Continue to reduce the optical phenomenon such as diffraction, severely affected Photo quality. Therefore, the smallest aperture of general non-professional DC is around F8, and a few machines such as A1, S602 have made F11, but there is no time.
~ Some digital cameras are displayed in the practice of shooting? how to use?
The histogram shows the grayscale distribution curve of the scene in the shooting range, and the color order distribution in Photoshop is the same. If the chart is continuous, it means that the grayscale distribution is uniform, and the hierarchy is rich. If the curve is undulating in the figure, it indicates that the contrast is large, and it is necessary to pay attention to the control. If there is a blank segment on the left, it means a high light portion. The level is too small (excessive exposure), can consider reducing exposure; if there is a blank segment on the right, it means that the dark level level is too small (the exposure is insufficient), and it can be considered appropriately increased exposure.
~ JPEG, TIFF, RAW photo storage format What is the difference?
JPEG is loss of compression, and the wake two is non-destructive compression, especially the RAW format is getting more and more popular. Since JPEG is damaged, it also needs to set the compression ratio to determine the quality of the final photo. Some DCs are used in the word "standard / fine / optimization" to represent different compression ratios, you may find that the image quality difference between "standard" and "fine" in most cases is not very large. If so you can save photos with "normal" file while saving the storage space of DC. It should be noted that when the JPEG photo is opened again, the loss will accumulate, and the image quality will further decline, so it is recommended to select "Save As ..." or turn the JPEG photo to TIFF format and then process again.
TIFF format is not owned by business organizations, nor is it dedicated to a software, compatible, and a variable compression. It is very common in printing and playing software.
The RAW format can be said to be a photo storage format specifically designed for digital photography. Although its file is large, it can be used in conjunction with a special RAW post-processing software. It can be very powerful and free to adjust photos of white balance, hue, etc., in some In case, you can quickly shoot without adjusting parameters such as white balance, providing a guarantee for easy shooting photos and final output ideals.
~ CF and SD card high speed, how is the low speed?
The CF card has a word of 16X 40X, 1X = 150KB per second, however this high speed generally refers to the speed of the CF card read, and its real write speed is generally less than that high speed, and the CF card High-speed writing also requires the cooperation of digital cameras, so high-speed CF card also has a compatibility problem. The CF high-speed card recommended in the general evaluation has PQI F1 (40x), Eagle's Turbo (fast number of writes), ScanDisk Ultra II, etc. SD card also has a high-speed low speed, but more than the CF card is simple, 2M per second and 10M per second, the outer packaging of the Panasonic SD card is indicated. In addition, the red SD card of Kingmax's PIP package is also a high speed card 10m per second. ~ Which digital cameras have the color better?
In fact, it can make photo color performance vary widely by setting up the color of the machine, but there are still some differences between different machines: Sight: Fuji, Kodak, Sony. The representative model has Fuji 6900, Sony F707, rich color, generally strengthened red and green, suitable for scenery photography, some colors feel that color performance is too fake. Realistic: USA, Olympus. Representative models have energy D7, Olympus C4040. The color restore is true, Olympus is light, it is convenient for later production, but some color friends feel that too much, don't like it. Warm type: Casio, Canon. The representative model has Casio QV3000, Canon G1. Casio weakened in non-scenic modes to weaken blue, G1 will be slightly biased, and the east is good. Of course, this is just the general effect of the default state, and many times can get the color performance you want by later processing.
~ Why is it for some time to see some red light (erythema) from the LCD halfway, and the photos taken are not red, how is it?
Two possibilities: 1. When shooting the subject in front of the bright window, there will be red vertical stripes, which is because the LCD has a "drawn" phenomenon on the light light, which belongs to the normal condition; When shooting a dark black object, the camera cannot focus, some cameras, such as the Sony F717 automatically open the auxiliary focus lamp, half-pressing the infrared transmitter before the lens, the infrared transmitter before the lens will emit a bunch of red light (which is composed of lines in different directions), After the completion, the red light disappears, does not affect the photo effect.
~ When you take a photo with a digital camera, I feel that it is difficult for the background. Why?
The virtualization background is to obtain the general shallow depth of the traditional camera, because the digital camera's imaging component CCD area is less than the area of the conventional camera film, so there is a "XX mm of the 35mm camera", but here is equivalent to "It's just a perspective, not all shooting effects are" equivalent ", such as digital cameras around 30mm physics, calculates, the depth of field is substantially equivalent to the depth of 70mm, and far from the perspective of the perspective. "The depth of field of 200mm traditional cameras. Basically digital cameras should use large aperture large zoom, perhaps to achieve a better shallow depth of field.
~ What is the best aperture?
The best aperture refers to a aperture value that is the best in camera imaging. The best aperture of the conventional camera lens is generally about two gears of the maximum aperture, that is, the maximum aperture is F2.8 lens, and its optimum aperture range is between F4 - 8. This is just the general rules analyzed from many lens assess data, and the lens of digital cameras can basically use this law. For example, when the Fuji camera is the maximum aperture of the maximum six-fold optical zoom, the edge imaging quality is significantly reduced, and the aperture is improved after the aperture; F11, the edge imaging quality is preferably, but the center imaging quality is not ideal; F8, the entire picture quality is more average, When the aperture F5.6, the center quality of the picture is best. ~ What is the lag when the shutter?
A common error is to shoot the scene box when shooting, see the shooting timing to press the shutter, this time the camera needs auto focus, light, calculate the exposure, select the appropriate exposure combination. . . . . All this requires time. If you count all the time as a "shutter time delay", then the traditional camera of auto-focus automatic metering is alive. The correct understanding should be, first press the shutter first, let the camera complete the autofocus, automatic exposure, etc., shoot the time, then press the shutter to the end, this time is the real shutter time. It is recommended to use digital camera to shoot more focus with manual focus, lock the exposure combination with manual exposure, so it is easy to obtain a short shutter time. Another problem is the interval of shooting, because the digital camera is different from the traditional camera has a process of storing photos, and it takes a certain amount of time. It is only a built-in super-cache individual camera to connect more. It is recommended to use a lower photo size when shooting quickly.
~ When shooting indoor or night view, I hope that people and backgrounds are clear, how do you operate?
The camera needs to support the slow synchronization of the flash, which is a high-level feature implemented by the camera and the flash. There are generally two modes: the front curtain synchronization and rear curtain synchronization. The forefront of the forefront will flash immediately after the shutter is fully opened, which is suitable for the general situation, easy to capture the character's appearance; rear curtain synchronization means flashing when the shutter will turn off, suitable for shooting moving objects, can pull out the movement trajectory of the object, Form a strong dynamic effect. It should be noted that when using slow synchronization, it is best to use a tripod because the shutter is turned out.
~ Photographs taken by digital cameras Sometimes it is prone to purple side, can you avoid? Can you eliminate software?
Purple Bide is a phenomenon in which purple (or other color) is present in the highlight portion and the low-light part of the highlight portion and the low-light portion. It is generally believed that the purple side is related to the camera CCD area, the internal signal processing algorithm, and the like. Different cameras have different severity of purple side, and it is not possible to avoid it. When shooting: 1. Try to avoid screen with high light and low light mutation; 2. Use average metering or partitioning, rather than point measurement to reduce contrast; 3. For important photos, if possible, try to use the RAW format record. There is currently not eliminated a special software for purple edge effects, which is more troublesome in Photoshop, you can try to use the "elimination of purple" action collected in PAA action, which is relatively simple.
The photo taken by the digital camera is always asks, not clear enough, color is not very bright, what should I do?
There are many reasons for this phenomenon, and one is different from different cameras. For example, Sony's camera F707 color is bright, the contrast is large, compares the favorite (but sometimes the distortion) Olympus machine color performance is very elegant, relatively elegant. If your camera has parameters like "Image Sharpness and Color Saturation Saturation", it is recommended to tighten these two values. In addition, external environmental factors such as light is not very good, poor air quality, low visibility, etc. may cause image darkness. A relatively simple method, you can use the post-processing action in the PAA action to improve, especially sharpening to improve the effect of such photos. It is recommended to download Focalblade to the PAA FTP site (a very powerful professional image sharpening tool). ~ Why do I have to press two shutters at the time of shooting, once a focus, one shot?
This friend is definitely not very well known to the two-stage shutters of the digital camera, and see the schematic of S5000 below. The shutter is more focus and metering, if everything is normal, press to complete the shoot, otherwise you can loosen your finger and then press the shutter to perform another test and focus.
