digital camera

1. Main performance indicators of digital cameras:

1. Pixels of digital camera:

In the process of shooting with a digital camera, because the photosensitive element that receives the signal is the digital camera CCD, manufacturers often use the pixels of CCD as the specifications of the digital camera.

A digital camera that only judges how many pixels it needs can be judged according to the formula, which is: image quality, image size × the square of resolution. ——

If it is generally only used for daily photography, that is, the output of 6-inch photos in the development library (generally 150DPI), 6x5x150x150 = 700,000, it can be seen that a digital camera with 800,000 pixels should be enough; If it is used to print 12 inch photos (the area is four times larger), you need to use a digital camera with12x150x150 = 2.7 million pixels.

2. The lens of a digital camera

The zoom multiple of digital camera lens is directly related to the level of digital camera grasping the original object. The larger the zoom of a digital camera, the clearer the photos of distant objects will be, and vice versa. Therefore, choosing a digital camera with large zoom can also effectively shoot distant scenery when you are away from home.

Digital camera zoom can be divided into optical zoom (physical zoom) and digital zoom. What really works is the optical zoom of the digital camera, which only allows the dual-camera object to be displayed in the viewfinder and has no effect on the clarity of the object. Pay attention to the difference.

The lens caliber of digital cameras also needs attention. If the aperture of a digital camera is small, no matter how large the pixel is, it will not shoot well in the dark.

3. LCD viewfinder of digital camera

There is nothing profound about the LCD viewfinder of a digital camera, mainly that the brightness should be high enough, the pixels should be large enough, and the larger the area, the better. At present, 1.5 inch to 1.8 inch are popular, as long as you pay a little attention when buying.

2. Other performance indicators of digital camera:

The performance selection mentioned above should be enough for us to generally choose digital cameras. But if you care about details, you should also look at the following aspects:

1. Control mode of digital camera flash

Because most indoor photography needs to use flash, most digital cameras can't connect flash, so the control method of digital camera flash is very important. Digital cameras with good functions can support various lighting control modes. If you often take pictures of people, you should choose a digital camera with the function of eliminating red eyes.

2. Digital camera aperture and shutter

The aperture and shutter of a digital camera are very important indicators when purchasing a digital camera. A good digital camera can take clear and beautiful photos at hand, but some digital cameras need to use a tripod, otherwise the image will be blurred or weak and cannot be used.

Three, the size and shape of the digital camera

In people's minds, the smaller the digital camera, the better. In fact, the small size of digital camera often means that the lens size is reduced, which means that it does not have the function of optical zoom, and the corresponding shooting and imaging quality will also bring some attenuation. This is where the digital camera is not satisfactory.

Fourthly, the compatibility of digital cameras.

The compatibility of a digital camera depends on its battery and memory card.

At present, all kinds of digital cameras on the market use batteries and memory cards with different shapes and full personality, so compatibility has become a big problem. The mainstream models are mainly SD and MMC cards, such as BenQ digital camera 24 10. In addition to Sony's special memory chips for digital cameras, a few digital cameras are still using CF cards that were commonly used before. This kind of camera is usually too big to be used at home.

Digital cameras in Japan have always been stingy, and many 5-megapixel products are only equipped with 32M memory cards. So it's best to buy a large-capacity matching memory card. Of course, if you have the strength, you can choose the popular digital camera companion. At present, 20G and 15G products sell well.

In terms of batteries, lithium batteries are the mainstream of digital cameras, but some brands of cameras use their own special batteries, which are incompatible and expensive.

When traveling, you must consider the battery life of the digital camera, otherwise the battery will run out and you won't remember the splendid scenery, which is a pity. Therefore, if the funds are sufficient, you can buy large-capacity batteries or ultra-large-capacity digital camera batteries from third-party manufacturers.

Of course, there are also many digital cameras that use the No.5 Ni-MH rechargeable battery with very good compatibility, and generally there will be no battery failure. For example, Samsung V3, V4 and other digital cameras are compatible with 6 or 7 kinds of batteries, which is very convenient for consumers.

Digital Camera-How to Choose a Digital Camera (2)

Digital cameras have entered the field of mass consumption. Many friends want to own a digital camera, but they don't know how to choose. As a digital product with high technical integration, there will be a problem of how to choose it in the purchase process. Now everyone pays great attention to the number of pixels of CCD when buying digital cameras. In addition to resolution, other performance indicators of digital cameras are more worthy of consumers' attention. I will tell you how to choose the "best digital camera" with real price and practical function from different angles.

First of all, know about digital cameras.

1. Digital camera pixels and resolution pixels are the most basic units of digital images, each pixel is a small point, and points (pixels) of different colors get together to become a moving photo. Digital cameras often use pixels as the basis for classification, but many people think that the number of pixels is the number of photosensitive points on the CCD photosensitive unit. In fact, this statement is not entirely correct. At present, many manufacturers adopt special technology. Digital photos with higher resolution can be made under the CCD photosensitive unit of the same photosensitive point, such as SuperCCD of Fuji digital camera and HyPic technology of Epson digital camera. What is the relationship between pixels and resolution? How to interpret these two figures when purchasing?

★ The higher the picture resolution, the more pixels are needed. For example, a picture with a resolution of 640×480 needs about 3 10000 pixels, and a picture with a resolution of 2084× 1536 needs at most 3 14000 pixels.

★ The resolution can have multiple values. The higher the resolution provided by a digital camera, the more flexible it is to take and save photos.

★ The resolution of the picture is related to the imaging size and magnification at the time of output. The higher the resolution, the larger the imaging size and the higher the magnification.

The total number of pixels in a digital camera refers to the total number of pixels contained in a CCD. However, due to the lack of light at the edge of CCD, some of them do not need to be photographed. Subtracting this part of pixels from the total number of pixels is the effective number of pixels. Therefore, when reading the product manual, remember to pay attention to the effective number of pixels that can be used in actual shooting, not the total number of pixels.

2. The quality of digital camera lens and shutter lens directly affects the quality of the camera. Under normal circumstances, manufacturers with deep traditional camera background will also have better lenses for their digital cameras.

★ The larger the aperture range of a digital camera, the more it can adapt to the lack of light. If there are more than two aperture values, the application flexibility of the camera will be greater. Aperture is one of the important mechanisms that affect exposure. It usually refers to the control device composed of about 5 to 9 pieces of metal in the lens group, which can form circles with different sizes to control the amount of light entering the lens. The larger the aperture, the more light per unit time. The size of the aperture is expressed by numbers. The larger the number, the smaller the aperture, that is, the less light enters. All the marks on the lens refer to the maximum aperture of the lens, that is, the value in the fully open state, such as 1: 3.2, but on the zoom lens, you will see the marks of 9.2-28mm 1: 2.8-F3.9, indicating that the maximum aperture is F2.8 when the focal length is 9.2mm and the maximum aperture when the focal length is 28mm.

★ Shutter The shutter of a digital camera can support 2 ~11000 seconds, which can meet the general requirements. Of course, if you have a wider shutter range, you can better meet all kinds of harsh shooting conditions, such as shooting high-speed moving objects or starry nights. The shutter is used to adjust the exposure time of the camera. The unit is seconds, expressed in reciprocal. For example, 30 and 250 represent 1/30 seconds and 1/250 seconds respectively, so the smaller the number, the slower the shutter speed. The faster the shutter speed, the easier it is to capture high-speed moving images. Generally, it is not easy to blur the image due to jitter when shooting, but high speed may lead to insufficient light input. Usually, when the light is strong, you must use a high-speed shutter or increase the aperture. When the light is insufficient, a slow shutter is more suitable, but a tripod may be needed for assistance.

3. Digital camera macro shooting macro is to zoom in and out the subject to be shot. The point is to shoot tiny objects to the size you want. In macro mode, all kinds of digital cameras have different abilities, and some of them can even be close to 0. 1 cm for close-up shooting.

4. Other functions of the digital camera, such as eliminating red-eye flash, white balance and exposure compensation, will have greater flexibility for shooting in various environments.

★ Automatic white balance correction The photosensitive part of a digital camera is equivalent to the negative of a traditional camera, and the photosensitive element of the digital camera is fixed, so it is necessary to use the white balance correction ability to reflect the change of the light source. It is mainly designed for photosensitivity in different environments. Different light sources will produce different degrees of chromatic aberration, which may make the color blue and yellow, and the white balance correction can be corrected.

★ Exposure compensation Because the automatic exposure function of digital camera is based on the amount of light reflected by medium gray, if there is too much white in the shooting picture (too much reflected light), the amount of light will be higher than the photometric standard value, so the camera will be misled into thinking that the light is very strong and the aperture will be reduced, resulting in underexposure of the photo and the white part will become not white enough. Exposure compensation is aimed at this situation. Only when the exposure is increased by 1 or 2 frames can a bright and correct image be obtained. On the other hand, in most cases of black, it is necessary to reduce the exposure of 1 or 2 squares.

1, digital camera lens. A well-designed high-end camera lens consists of multiple groups of lenses, including aspherical lenses, which can significantly reduce color shift and minimize graphic distortion and distortion. Expensive fluorite or glass is used as a lens. In order to reduce weight and cost, the lenses of household and semi-professional cameras are made of resin.

2. Image value of CCD of digital camera. CCD is the heart of digital camera, and it is also one of the main factors that affect the manufacturing cost of digital camera. Therefore, the classification of digital cameras has become an important standard. At present, entry-level products are all 3-5 million pixels, and commercial and semi-professional users prefer products with more than 5-/kloc-0.0 million pixels.

3. Zoom of digital camera. Optical zoom is a real zoom, which will not affect the imaging quality of photos; Digital zoom is electronic zoom, which is a local enlargement at the expense of photo clarity.

4. Battery and power consumption of digital camera. Digital cameras have LCD display and built-in flash, so the battery consumption is larger than that of traditional cameras. It's cheap to use the No.5 battery, and you can buy it anytime and anywhere, but it won't take long for the battery to die. Therefore, it is best to choose the model equipped with rechargeable lithium battery. At present, mainstream digital products have been designed as lithium batteries, and complete charging equipment is provided as accessories.

5. Additional functions of digital camera. The more functions, the more fun and uses it means to use a digital camera. For example, many digital cameras have video output function, which can be connected to TV to browse photos; Some can set their own startup screen and shutter sound like mobile phones; Some can have short-term digital video recording function. The driver installation of digital camera should be very simple, and it should be able to download pictures quickly and preview them. For example, the software function attached to Canon digital camera is perfect, which can classify and manage pictures, and the settings when printing are more diverse, and pictures can also be simply modified.

Image sensor is the decisive factor of digital camera performance. Generally speaking, the pixel value of the image sensor should be greater than the maximum pixel value of the real shot image. In order to make up for the pixel shortage of image sensors, some manufacturers use software interpolation to improve the pixel value of images. In fact, this interpolation method can be realized in almost all image processing software, so it is of little practical significance. The purchase must be based on the hardware pixel value of the image sensor, not the maximum pixel value of the output image.

Digital cameras record photo information in a semiconductor element called CCD (Charge Coupled Device), instead of the film of a silver salt camera. The size of CCD, like TV, refers to the diagonal length, expressed in inches, such as "1.27 inch (note)". The larger the CCD, the more pixels and the higher the sensitivity. Therefore, with the same number of pixels, the larger the CCD, the better the image quality. CCD size 1/2.7 inches (4.0mm×5.3mm) 1/2 inches (4.8 mm× 6.4 mm)1/0.8 inches (5.19 mm× 6.9/.

Second, the four principles of digital camera purchase

● For ordinary home users, if they are limited to family entertainment, they pay great attention to practicality. Powerful functions and high cost performance brought by durability are the first choice factors. At present, more than 5 million digital cameras that dominate the market can meet the imaging requirements. A variety of shooting modes, a wide range of ISO values and high-speed and accurate focusing are necessary functional characteristics, and a metal shell that ensures durability is also an essential consideration.

● For those consumers who pursue fashion avant-garde, the close combination of digital camera shape design and highlight function is the preferred standard. Small shape, bright colors and comfortable hand feel are essential, and some highlight functions, such as macro shooting, are icing on the cake for this kind of products.

● If you are a professional user, the most important thing is the ultimate pursuit of imaging quality by digital cameras. Manual operation function is necessary. Replaceable lens, CMOS image sensor with more than 6 million pixels and various image recording modes are the guarantee of high image quality. If we have an explosion of less than ten thousand yuan, more professional photographers will flock to us.

The last thing to consider is where to buy a digital camera. A regular digital camera sales counter will ensure that your camera is "born". Brand effect should be considered when purchasing, because it is the main guarantee for the overall quality and after-sales service of digital cameras.

Third, the preparation steps for buying a digital camera

Step 1: Make clear the purpose and purpose of buying a digital camera.

It is very important to determine the purpose and purpose of buying digital cameras. Only by knowing your own needs can you choose to buy the digital camera you really need through mergers and acquisitions. Otherwise, you may spend a lot of money on the camera, and it turns out that the functions can't meet your own requirements, or there are too many functions to use at all. We can think about what we buy digital cameras for. For example, some friends buy digital cameras to travel; Some friends want to learn photography; Some friends want to take macro photos; Of course, some people want to take close-ups or take pictures of their newborn children as a souvenir. In short, we must clearly understand consumption.

The output of photos also needs to be considered in advance, whether it is necessary to develop large photos or just watch them on the screen. Through this consideration, we can decide how many pixels we need to buy a digital camera. If you just look at it on the screen, then a 3 megapixel machine is enough. If we want to print, and print to more than 10 inch, then we need to buy a camera with pixels as high as possible.

Step 2: Decide the psychological price.

After deciding the purpose and use of buying a digital camera, you should decide an affordable psychological price according to your own economic ability, such as 3000 ~ 4000 yuan or 6000 ~ 7000 yuan. This can help us save a lot of time and be more purposeful when choosing. Digital cameras are still luxury goods, so we must do what we can. There is no point in comparing with others, just enough.

Step 3: Collect information through various channels.

It is very important to collect information in advance, so as to have a certain understanding of the digital camera to be purchased. There are many ways to collect product information. First of all, many manufacturers will have certain publicity pictorial when they launch digital cameras. We can go to the vendor and have a look. Secondly, media advertising is also a very important way. There are many advertisements for digital cameras in IT newspapers now, so we should pay attention to them. Thirdly, many digital magazines or some newspapers now have a certain space to introduce or evaluate digital cameras, and we can also buy some to read.

If possible, you can download the manual of the corresponding camera and have a look. This is very good for buying a machine: on the one hand, it can make you more familiar with the machine, on the other hand, it can make you ready for basic operation when buying a machine. I like reading instructions myself.

Technical data can let us know the appearance, function and other information of digital cameras. We should look at the actual photos. In this way, you can know the characteristics of DC you are concerned about, such as color, image quality and so on. We can go to the digital photography website to learn about this.

Step 4: roughly determine the model of the digital camera.

The collection of product information is very important, which allows us to fully understand the characteristics of digital cameras. But just looking at these materials, we can only have a perceptual understanding. Only by actually looking at the machine or even trying it out can we have a rational understanding of the machine. This requires us to go to the mall. We can look at the samples in the window or counter. A real digital camera may look different from the one in the photo, or it may look better. We can also watch others buy machines and listen to what others say. Of course, we can also let the merchants take out the machine, actually touch it and operate it. Depending on the machine, you should also ask the price. When asking about the price, you should pay attention to the fact that the quotation of the merchant usually leaves room for counter-offer. Also, ask them if the price they quoted is licensed or parallel.

Step 5: Choose the right time to buy.

After deciding which digital camera to buy, you should choose "auspicious day" to buy it back. When I say "auspicious day", I actually want to seize the opportunity myself. The price of digital products changes rapidly, so it is very important to judge the market. However, obviously, you should avoid buying before the festival as much as possible. There must be a lot of people buying machines before the holiday, and the price will not be cheap.

Buying a digital camera is a must-read on the spot.

When buying a camera, you need to check it carefully to avoid buying defective products or being cheated by JS (profiteer). Here we give a detailed inspection step, as long as you follow the following instructions, there will be no problem:

1. Never pay JS first, and then pay after inspection;

2. See if the packaging is old. If so, it may be replaced by others, or a product that JS has stored for a long time;

3. After unpacking, check whether the accessories in the box have been used or obviously disassembled; Pay special attention to whether there are scratches on the battery pins;

4. Check the appearance of the digital camera. Look for scratches on the fuselage, including lens, LCD, EVF and shell.

5. Try to shoot, and zoom to see if you can shoot clearly. If you are not familiar with the digital camera you are going to buy, you can use automatic shooting during the trial. In addition, the flash has to be tried;

6. Then take a closer look at the LCD and EVF of the digital camera. You can block the lens a little with your hand, so that you can see a solid color image, or face the black and white paper.

7.CCD is the key component of digital camera. If there are bad spots on it, it will affect the shooting. Because it is difficult to see the bad point of CCD directly on digital camera, it is necessary to import the picture into PC and watch it again. If there is no computer in the business, it is recommended to talk with the business about a certain replacement cycle, and then go home and feel at ease to test;

How to test the bad points of digital cameras

Before discussing how to test the bad points of digital cameras, we have to explain what bad points are. Simply put, it is a point on the CCD that will never be sensitive, or this point will always be on. Usually always at the top, rarely not. So why is there a bad point? This is related to the manufacture of CCD. Although the technology is very developed now, it still can't guarantee the high output of CCD. Just like LCD, it may be defective. So we need to test the machine after we buy it.

In fact, it is relatively simple to test the bad points of digital cameras. We can test it in two ways: one is to look at the original picture with our eyes. In fact, this method is more intuitive, but be careful, otherwise it is easy to miss points. The second is to test with software. The most popular bad point testing software is DEADPIXEL. Usually, if there is a computer in the place where DC is sold, this software can be bought there.

Before the test, we should take some all-black photos first. Ordinary photos can't be tested. This is very important. For the machine with lens cover, we only need to cover the lens cover to shoot. If there is no lens cover, such as Casio, then we can put a thick piece of paper on the flat panel, put down the DC lens and buckle the lens on the paper to shoot. It should be noted that the light must not enter the lens, and at the same time, don't use too much force, which will easily damage the machine.

The shooting parameters can be set to the maximum aperture and ISO 100. As for the shutter, we need to choose 1/60 and the slowest shutter. That is, take a photo with different shutter speeds.

After shooting, we can import the photos into the computer and open DEADPIXEL for testing. After opening this software, we can see the interface as shown below. We click the "Browse" button and select the photos that need to be tested. Then we press the test button and the results will appear. If the photo of 1/60 is more noisy than 10, try to change it, otherwise it may affect the shooting.

Check that all accessories are there. Usually there is a list in the box, which explains in detail how many accessories are included, and we can compare them.

Skills of distinguishing parallel goods from licensed goods with digital camera

Guests often ask me how to judge licensed goods. Generally, licensed goods are clearly marked. Let me briefly say:

1. Canon digital camera: there is an anti-counterfeiting mark on the licensed packaging box, and you can check it by phone after scraping off the coating; The serial numbers on the packaging box, warranty card and fuselage should be consistent; Canon's triple warranty card has a laser anti-counterfeiting label in the upper right corner, and the warranty card is in Chinese; The instruction manual is a simplified Chinese version.

2. Fuji digital camera: At present, all authorized Fuji have Chinese menus. If the menu is found in English, it can basically be regarded as parallel imports; The outer packaging of the licensed goods is in Chinese; Licensed goods have a simplified manual; As for the warranty card, Fuji Licensed Products provides a simplified version of Fuji China warranty card in triplicate.

3. Minolta digital camera: You can call Shanghai Minolta's toll-free hotline: 8008200077, and ask it to verify the body number.

4. Nikon digital camera: Since Nikon has no company in China, its sales are handled by several agents, namely Quantum, Lida, Liangchi and New Kang Hua. Each agent's licensed goods identification method is not exactly the same, but there are still some ways to identify them. First, we need to see the warranty card. The authorized warranty card is in English with the agent's seal on it. Licensed goods are described in simplified Chinese. Some agents, such as Quantum, put anti-counterfeiting labels on boxes.

5. Olympus digital camera: Olympus machines now use simplified Chinese menus, but there are still few products with English menus; Secondly, the manual and warranty card are also simplified Chinese versions; In terms of outer packaging, Olympus is a simplified Chinese version.

6. Sony digital camera: the label of Shanghai Suoguang or Wuxi Sony can be found on the licensed packaging box; The warranty card has the words Shanghai Suoguang; There are simplified instructions. Sony DC or DV sold in China market are only made in China, and all imported products are parallel imports. You can see the words CN 1 on the bar code of the outer package. If it is CN5, it is parallel imports.

7. Casio digital camera: After purchasing, customers can scrape off the coating on the anti-counterfeiting label attached to the package to obtain the password under the coating, and make inquiries in three ways:

1. Call 8008 1083 15 for free telephone consultation or 0 10-642 19000 for consultation.

2. Send short messages to 800283 15 (mobile) and 900283 15 (Unicom) for inquiry. "

Note: Now many good digital camera brands have their own websites. As long as you log on to the corresponding website and enter the body number, you will know in a few seconds whether the DC or DV you bought is licensed or not. If you bring DV or DC from abroad or Hong Kong and Macao, you'd better ask if there is a warranty in China. As far as I know, except Panasonic, other brands have no warranty in China, and not all Panasonic products have warranty in China. At present, most maintenance departments in China are contracted, and if there is no formal warranty, the maintenance fee is surprisingly high.

Pay attention to buying digital cameras

Is a digital camera equal to a high-quality photo with high pixels?

Many users who buy digital cameras for the first time will take pixels as the primary consideration. In their view, pixels are the basis for judging the quality of digital cameras. It seems that a high-pixel digital camera is bound to get high-quality shooting results. In fact, the relationship between pixels and image quality is far from simple.

One thing is certain, the pixel height does not determine the quality. There are many factors that affect the quality of digital cameras, among which the lens can directly affect the imaging quality. Whether it is an optical camera or a digital camera, the lens is one of the most important factors. Ordinary digital cameras use CCD to sense light, the area is much smaller than that of traditional film, and the resolution of the lens is more stringent, otherwise, even if the pixels are higher, the imaging quality will deteriorate because of the lens. In other words, the resolution of optical lens used in digital camera must be better than CCD, so choosing a digital camera with high quality lens is much more important than simply looking at pixels.

Low noise and clean pictures of digital cameras are always accompanied by high resolution?

Noise is the enemy of digital camera imaging quality. General users will think that a clean picture with low noise always means a high-resolution effect of photos. In fact, for digital cameras, the situation is not that simple. Because the image sensor of digital camera is very single, it is nothing more than CCD or CMOS, that is to say, the image engine signals of each other are close. The post-processing of image data has created the style differences of different brands and different series models, which is the embodiment of the core technologies of various manufacturers, especially the research and development degree of noise reduction technology has a great influence on the resolution.

The higher the ISO of digital cameras, the louder the noise?

Slightly experienced digital camera users sometimes use high sensitivity settings when shooting moving objects or in dark environments. When shooting with high ISO value, the shutter speed is faster and shooting is easier, but one problem brought by high sensitivity is that the picture noise will increase. In fact, this is a headache for many digital camera users, with low sensitivity, difficult shooting, less noise, high sensitivity, easy shooting and more noise. Generally speaking, we should reduce the resolution of high-sensitivity photos, but the noise in the photos is not so obvious. This is simply because one pixel in the reduced image is obtained by merging the original pixels. In other words, three noises become one noise, which is not a strict explanation, but it can help us understand this phenomenon.

How many pixels is the best for each camera under high sensitivity setting, which requires the user's own actual experience. Let's make an analogy. If they are all under the setting of ISO400, the shooting noise of a 2-megapixel digital camera may be the smallest under the setting of 640×480 resolution, while a 5-megapixel digital camera can get good results under the setting of 1024×768 resolution.

The higher the number of CCD pixels, the faster the focusing speed can be?

Let's take a look at the early digital cameras. Just because ordinary digital cameras have to read CCD imaging signals when focusing, focusing and response speed used to be the eternal pain in the hearts of the first generation of high-pixel digital cameras. The increase of pixels means that the data amount of CCD signal is also increasing every time, and the subsequent processing such as focusing, photometry and liquid crystal display is also a burden. Therefore, we can often see that in the digital camera series based on the same hardware platform, the speed of low-pixel products is often higher than that of high-pixel "big brother".

Lithium battery is the first choice for digital camera power supply because of its high energy density and small size?

First of all, we need to know what is a big power consumer in digital cameras. LCD screen, flash lamp, image sensor and processing engine are all big power consumers, and they are all sudden, but they need large current at the moment of work, and the static current at ordinary times is very small. This determines the power consumption characteristics of digital cameras, and requires the power supply to have the ability of sudden large current supply. From this point of view, the battery with low internal resistance is more suitable for digital cameras, which can obviously improve the response speed of digital cameras. From the analysis of the average charging time of flash, the camera of lithium battery is far ahead, usually only 3 seconds, while the model of Ni-MH battery is often more than 6 seconds.