BTC historical lowest price
CPU mining → GPU mining → FPGA mining → ASIC mining → large-scale cluster mining
while mining chips are updated, The change of mining speed is:
CPU (20mhash / s) → GPU (400mhash / s) → FPGA (25ghash / s) → ASIC (3.5thash / s) → large scale cluster mining (3.5thash / s * x)
mining speed, which is called computing power in professional terms, is the ability of computer to generate hash collisions per second. In other words, how many hash collisions can our miner do per second is the calculation force. Computing power is the ability to dig bitcoin. The higher the computing power, the more bitcoin you dig, the higher the return
in the world of bitcoin, a data block is recorded about every 10 minutes. All mining computers are trying to package the data block and submit it, and the person who successfully generates the data block will get a bitcoin reward. Initially, bitcoin rewards of 50 bitcoins could be generated about every 10 minutes. But the payment is halved every four years, and now the bitcoin network can generate 25 bitcoins every 10 minutes
in order to successfully generate data blocks, miners need to find the effective hash value. To get the correct hash value, there is no shortcut. They have to guess. The process of guessing is the process of computer random hash collision. If you guess correctly, you will get bitcoin
so far, the highest 1btc price in bitcoin history is about $20000, with a market value of more than $60 billion.
In 2009, when bitcoin first appeared, one dollar could buy 1300 bitcoins. In 2010, it was only $0.003. In November 2013, the highest price created by bitcoin reached 8000 yuan for the first time. In 2017, bitcoin's price rose wildly. In this year, bitcoin once created the highest price in history, with the highest value of about 20000 US dollars
that is to say, a bitcoin costs about 130000 yuan. According to the proportion, bitcoin has soared by 2.73 million times in eight years, becoming a well deserved proct with huge profits. According to the data of coindesk digital currency trading platform, the price of bitcoin once fell below $6000 in 18 years, and it has dropped 70% compared with the highest value of $20000 in 2017
with the decline of bitcoin, many digital currencies have been affected, with a decline of more than 10%. It has been less than 10 years since the development of digital currency. Many large enterprises can't compare with it. It can be seen that the future of digital currency is worth looking forward to
according to the data of coindesk digital currency trading platform, the price of bitcoin once fell below US $6000 in 18 years, which has dropped by 70% compared with the highest value of US $20000 in 2017
"the price movements we are seeing now may seem drastic, but they are quite normal for this market." Etiro's senior market analyst, MATI Greenspan, wrote in an email to CNBC
with the decline of bitcoin, most digital currencies are affected, and other digital currencies are not much better. Most digital currencies are down by more than 10%. But in the long run, the future of digital currency is worth looking forward to.
The price of bitcoin is about 9800 yuan
bitcoin (bitcoin) is a kind of network virtual currency, which can buy real-life goods. It is characterized by decentralization, anonymity, and can only be used in the digital world. It does not belong to any country or financial institution, and is not subject to geographical restrictions. It can be exchanged anywhere in the world. Therefore, it is used as a money laundering tool by some criminals. In 2013, the U.S. government recognized the legal status of bitcoin, making the price of bitcoin soar
starting from the essence of bitcoin, the essence of bitcoin is actually a special solution generated by a bunch of complex algorithms. A special solution is one of the infinite (in fact, bitcoin is finite) solutions that can be obtained from the equations. Every particular solution can solve the equation and is unique. The process of mining is to continuously seek the special solution of the equation system through huge amount of calculation. The equation system is designed to have only 21 million special solutions, so the upper limit of bitcoin is 21 million

ten years from now, the price of bitcoin is unknown On December 17, 2017, bitcoin reached an all-time high of $19850. On June 22, 2019, the price of bitcoin broke through the $10000 mark. Bitcoin prices fluctuated around 10200, rising nearly 7% in 24 hours
On June 26, the price of bitcoin broke through US $12000, a 17 month high since January last year. In the morning of June 27, the price of bitcoin was close to $14000, reaching a new high of the yeartherefore, the future price trend of bitcoin is uncontrollable
4, low transaction costs:
bitcoin can be remitted free of charge, but in the end, a transaction fee of about 1 bit will be charged for each transaction to ensure faster transaction execution
1. Take close-up pictures of small still objects, such as flowers, birds and insects:
use AV file, the aperture should be f5.6 or below, the focal length should be more than 50, and try to shoot within 1m to make the background virtual
if the light is good, ISO 100, if the light is bad, ISO should be within 400<
2. Shooting people:
basically use a large aperture (within f5.6) and a focal length of more than 50 mm. The shooting distance depends on the whole body, half body and big head, which makes the background virtual. Use AV file
good light, iso100, bad light, iso400
people in motion use tracking to reflect the sense of motion (see the shooting of moving objects below for details)<
3. Shooting:
AV file, use the appropriate aperture, above F8, the focal length is arbitrary, but generally the wide-angle end has distortion, use it as appropriate<
4. Shooting night scene:
upper tripod, AV gear, custom white balance or incandescent lamp, aperture above F8, small aperture can make the light proce starlight effect, use the reflector pre rising function to rece the vibration caused by the reflector lifting after pressing the shutter; And cover the viewfinder with the square cover on the strap to prevent stray light from entering from the back and affecting the image quality; ISO 200, as far as possible to make the exposure time longer, so that some people who have no intention to walk away from the screen disappear, leaving no traces, clean the scene
for example, when taking a square with people coming and going, you can use a very small aperture of about F20 and iso100. In this way, the exposure time will be very long, and the moving figures will not stay in the photos! The square will be clean<
5. Shooting fireworks:
using shutter line and B shutter, you can shoot multiple fireworks overlapping effect<
6. Shooting things:
when the light is good: AV, the aperture size should be handled according to the circumstances; Large depth of field can be obtained by using aperture above F8, and shallow depth of field can be obtained by using small aperture
if you want to have a very dynamic effect, you can use the TV gear, the shutter is about 1 / 30, when you focus and press the shutter, the lens will follow the object at an appropriate speed, which will proce a very dynamic effect
poor lighting: we can only handle it according to our own discretion, plus use the follow-up camera<
7. Shooting running water or fountain:
using TV and about 1 / 50 shutter speed, you can shoot Satin effect. If you use too fast shutter speed, the fountain will shoot discontinuous water drops<
8. Taking photos at night:
use tripod to adjust white balance, and automatically or custom white balance; iso100-400 AV gear, aperture about F8, use slow synchronous flash, rear curtain flash mode; At this time, the flash will flash twice, press the shutter to flash once, and flash again before the end of exposure, so don't leave before flashing twice
in this way, the characters can be clear and the background neon is beautiful, so that the background will not be too dark e to insufficient exposure< No matter what you shoot, don't shoot with the maximum aperture unless you want to keep a safe shutter
2. Please use the aperture of F8 ~ F11 as much as possible when shooting scenery
3. The maximum aperture can be reced by 1-2 levels when taking close-up of people and still life
4. The safety shutter should be controlled above the reciprocal of the focal length as far as possible. The wide-angle shutter should also be more secure at more than 1 / 30 second. If the shutter is insufficient, please increase the aperture or ISO<
metering method:
1. Don't measure the light to the sky or the darkest place. Go to the middle value
2. According to your subject matter, make good use of the metering mode (balance metering, point metering, central key metering...)
3. If the light measurement is not accurate, please use AE lock to expose and lock the gray things around you before shooting
4. Try not to measure the light on white or black objects, otherwise remember to rece eV for black and increase eV for white<
EV is exposure compensation.
exposure compensation is also an exposure control method, which is commonly used in ± If the ambient light source is dim, the exposure value (such as + 1eV, + 2eV) can be increased to highlight the clarity of the picture
most of the small digital cameras adjust the exposure compensation through the menu
in the process of shooting, if you press half of the shutter, the LCD will display pictures similar to the final effect picture, focusing and exposure will start. The exposure at this time is exactly the exposure of the final picture. If the picture is obviously bright or dark, it means that the automatic metering accuracy of the camera has a large deviation, and the exposure compensation should be enforced, but sometimes the brightness displayed ring shooting is different from the actual shooting result. Digital camera can browse the picture immediately after shooting, at this time, you can more accurately see the brightness of the picture, there will be no difference. If the shooting result is obviously bright or dark, it is necessary to re shoot and force the exposure compensation
the shooting environment is dim, and the brightness needs to be increased. When the flash cannot work, the exposure can be compensated and the exposure can be increased appropriately. For exposure compensation, if the photo is too dark, increase the EV value. Every 1.0 increase in EV value is equivalent to doubling the amount of light intake. If the photo is too bright, decrease the EV value. Every 1.0 decrease in EV value is equivalent to doubling the amount of light intake. The compensation interval can be adjusted in 1 / 2 (0.5) or 1 / 3 (0.3) units according to different cameras
when the white object to be photographed looks gray or not white enough in the photo, it is necessary to increase the exposure. In short, "the whiter the object is, the more white the object is." this seems to run counter to the basic principles and habits of exposure. In fact, it is not. This is because the main body of the camera is often the center of the light measurement, and the White main body will make the camera mistakenly think that the environment is very bright, As a result, the exposure is insufficient, which is also a common problem for most beginners
because the shutter time or aperture size of the camera is limited, it is not always able to reach the 2eV adjustment range, so the exposure compensation is not omnipotent, and it may still be underexposed in too dark environment. At this time, it is necessary to consider cooperating with the flash or increasing the ISO sensitivity of the camera to improve the brightness of the picture
generally speaking, the smaller the brightness contrast of the scene, the more accurate the exposure, otherwise, the larger the deviation. The grade of the camera is high and low. If the grade is high, the metering is more accurate, and if the grade is low, the deviation will be increased. If it is a traditional camera, the tolerance of film is relatively large, and the exposure deviation will not have a big problem within a certain range, but the CCD tolerance of digital camera is relatively small, and slight exposure deviation may affect the overall effect
in a word, the adjustment of exposure compensation is determined by experience and sensitivity to color. Users must compare the image quality, clarity, restoration degree and noise size under different exposure compensation to get the best picture
note:
the aperture in Canon's manual refers to the F value. The larger the aperture, the greater the depth of field
generally speaking, aperture refers to aperture, which is inversely proportional to F. the larger the aperture, the smaller the depth of field
AV -- aperture priority auto exposure
TV -- shutter priority auto exposure
AE auto exposure
AF auto focus
AF-S -- single auto focus, the same as saf. The opposite is continuous autofocus
MAF - monitor AF, which can shorten the focusing time. The camera will adjust the focus before half pressing the shutter button, so that you can compose with the adjusted focus. When the shutter button is half pressed and AF locking is completed, the focus will be locked
ev - exposure value, which is usually used in exposure compensation
ISO sensitivity. Each difference of sensitivity is equivalent to the corresponding exposure value of aperture or shutter
brother, if you have time, go to ZhongGuanCun video forum and see the forum.
the price of Leyte is determined by supply and demand. When the demand for Leyte increased, the price of Leyte increased; As demand decreases, prices fall. At present, only a small number of leytes are in circulation, and new leytes are issued at a predictable rate of graal decline, which means that demand must follow this inflation level in order to maintain price stability. Compared with the market scale it may become, Leyte is still a relatively small market. It does not need a lot of money to make the market price fluctuate. Therefore, the price of Leyte is still very unstable.
Here is the latest bitcoin market chart of China on July 13:

