As one of the large three-element standard zoom lenses, 24-70mm focal length has always been a focal point for military strife. It just spans the wide-angle end and middle-focus end, and has a relatively wide range of applications. In the big three yuan, it can be described as a mirror walk. The world. Its wide range of applications and large constant aperture f2.8 have won praises and are the main products that Nikon (N Home) and Canon (C Home) have invested great effort in R&D.
Large three-dimensional zoom lensFirst of all, let's distinguish between the big ternary combinations of N and C homes. The big ternary of N homes refers to the following three shots: 14-24 f2.8G ED (commonly known as the big light bulb), 24-70 f2.8E ED VR ( Also known as 24-70 II), 70-200 f2.8E ED FL (commonly known as the electromagnetic gun); C family of large ternary refers to: 16-35 f2.8 III, 24-70 f2.8 II, 70 -200 f2.8 IS II (commonly known as the white rabbit), these six lens prices are higher, the average price of more than 10,000 yuan alone, in the zoom lens integrates two of the top technology, can be called zoom lens Huang. N's shots seamlessly connected to 14-200 focal lengths, while the C's wide-angle end overlapped.
N- and C-home 24-70The main product introduced today is the standard zoom lens 24-70 f2.8II, so it involves more than super wide-angle and medium telephoto lens, first on a group of N and C 24-70 lens images.
In terms of value, the author may prefer the N family's shots, slender, with anti-shake and gold circle blessing, of course, the red circle of the C family is not to be outdone.
Canon 24-70 f2.8 II USMAs the top standard zoom lens of 135 frames, the 24-70 f2.8II is absolutely superb in the use of materials. The lens structure uses 13 groups of 18 and 16 generations. The filter size is as high as 82mm (5mm larger than the previous generation, of course, Sigma is black The technology 85 1.4 filter size is larger (up to 86mm), ensuring the amount of light into the light, using a circular USM drive motor, the minimum aperture is 22, the maximum aperture is 2.8, the aperture blade is 9, more than one generation, weight 805g, The lighter weight of 145g brings a strong plastic feel. The special lenses used two UD lenses and a super UD lens in the second generation, and only one UD lens in the generation. In addition, the second-generation front lens has been added with an anti-fouling fluorine coating. The official saying is that it is not necessary to use a UV lens, but the author's words are not too large to expose it to the outside. Note: The protective and all-metal body grip brought by the huge hood of a generation still makes many friends put it down.
The following is a group of 24-70 f2.8L and 24-70 f2.8 II lens structure diagram, the picture shows the first generation, the following figure is the second generation.
MTF (Modulation Transfer Function) modulation transfer function curve, the author as a typical engineering student, the first time I saw the word associated with the "signal analysis and processing" in the modulation and demodulation and "automatic control theory" in the transfer function. The principle and measurement method of the MTF curve are not introduced too much. The MTF is one of the important considerations of the lens technology evaluation and is a reference for measuring the contrast and resolution of the lens.
MTF is a ratio, the MTF value is M'/M, the closer the lens is to 1, the better the lens performance is. Due to the limitation of the optical principle and structure, the MTF value cannot reach 1 in the low frequency band. In the high frequency band, the MTF The value will gradually decline.
The following are MTF curves for 24-70 f2.8L and 24-70 f2.8II
Obviously from the parameter level, the performance of the second generation has significantly improved compared to the previous generation. This may be attributed to the role of the Super UD lens.
The reason for buying such a lens is that the author has a portrait focusing head, which is perfect for shooting portrait blur effects and out-of-focus effects. The straight-out effect is not bad, and there is no suitable purchase in the wide-angle to medium-cook end. Lens. Once used 24-10L with 6D, personal common focal length is probably in this range, when the second generation has not yet been out. In order to travel conveniently, I still prefer a zoom lens (introduction to white, not a good understanding of fixed focus), so I chose the 24-70 f2.8II USM, one of the second-generation big three yuan produced in 2012. Facts have proved that I have no regrets about choosing this lens. After all, the price just listed on the market is as high as 18,000. Now it is, which is a price range worth starting.
Canon EF 24-70mm f/2.8L II USM Standard Zoom Lens 11999 Canon's Full Frame Ultimate Lens King, Good Price at 10999 Jingdong Direct Link Encyclopedia Appearance Come for a fake out of the box
Boxes and accessories
The box is nothing more than a lens bag, hood, warranty card, lens body and cushioning foam board.
Automatic manual AF/MF switch, did not join the anti-shake technology, guess the third generation will join anti-shake.
LensMulti-angle shots
You can see the focusing window, the closest focusing distance is 0.38.
Compared to the first generation, the second generation added a focal length lock switch, and the mother would never worry that the lens would be "automatically" extended.
Body fit diagram Main view
Side view
Top view
Side view after zooming
After adding the lens, measure the length and width of the machine by hand: the length of the fuselage is 145mm and the height is 118mm. The distance from the front lens to the eyepiece lens hood is 200mm, and after zooming, it reaches 235mm (no hood is installed).
Add flash picture
Behind the table lamp or 99 yuan Panasonic lamp recommended by Aunt.
FilterAlthough 24-70 II was added with an anti-fouling coating, I was reluctant to allow him to "run naked," equipped with a B+W ultra-thin, multi-layer coated UV mirror, a digital master's ultra-thin CPL polarizer, and a blue gradient lens. , have to say 82mm size filter is still very expensive for the general also bought 77 to 82 adapter ring.
UV Mirror
It is a lot lighter and thinner than single copper rings.
CPL
Blue gradient mirror
The body has two card slots, one is the CF card slot, one is the SD card slot, SD card has been mentioned in the first article, the following is a CF card out of the box
Already verified anti-counterfeiting, SanDisk can only be checked once, the second time can only verify the phone, lifetime warranty.
The box stuff is simple, a one-year data recovery card and a CF card.
positive
back
Transmission speeds up to 160Mb/s, twice as fast as SD's 90Mb/s.
Use feeling weightIn terms of weight, this large ternary standard zoom lens of only 805g is already very light, 82mm filter size and lens width brings a very good sense of grip (the author is relatively large).
Zoom focus Focus ring damping is very good, and iphone feels like out of the box, the zoom direction is opposite to N lenses, the focus ring rotation is very easy, smooth. Used in the 5D body, auto focus is very fast, very quiet, do not run out of focus.
The C sunshade has flocking, which can effectively absorb light and prevent reflection, but the result is capacity! easy! drop! gray! This problem has become very common. You can use plastic tape to stick dust over time.
Previously, there was less sample out of the box, and the valued friend vomited. This time put a few more and it is estimated that it will be sprayed....
Xiamen
Gulangyu Night Shot
Zeng Zhen eats and eats
Starry sky
The aperture is fully open and the vignetting is still obvious.
The Palace Museum
Olympic Sports Center
Xingmang pretty
This one on the map has been sent out of the box
CBD climbing stairs
National Theatre, sidelights turned on during the two sessions
Sunset clouds
There are so many, I don't like to touch him, and you have the sister you want.
C-family 24-70 f2.8II is still a very worthwhile purchase lens, but this focal length has its universality, but also his short board, the high does not succeed, the wide-angle end when shooting the scenery is a bit limited, Especially when the sky and the vast landscape are seen, the effect of blurring the characters is not as good as that of the big eyes. However, as a mirror to go the world, the application scene light, small size, light weight, fast focus, zoom. Since I have not experienced the 24-70 f4 and 24-105 f4 II generations, the author does not compare the three lenses here. The f4- 24-70 has a macro function and should be able to become a mirror lens.
Use of CCThis CC is not a CC, not a CC version of PS, but an abbreviation of Camera Connect. This is Canon's own mobile phone control camera app, and has the function of WiFi mapping, similar to the WMU of Nikon, but functionally The WMU is much stronger and both apps are controlled using wifi.
Wifi useHere, I had to spit on the issue of the fruit machine. At that time, the wifi connection took nearly two hours. It was said that I also paid the IQ tax. Basically, I tried all the online methods. The mobile phone did not pop up the dialog to connect wifi. ..... In the end, the author resorted to the ultimate move, shutdown and restart! As a result, the app actually connected, and I really want to burst the mouth!
CC appThere are two applications in the Apple App Store. They are Camera Connect and EOS Remote. If you can't figure out which to use, select CC and you're right.
Main interface The main interface of ER
The official use of CC is recommended, CC is an upgraded version of ER.
CC's main interface
After connecting the camera, the following function menu can be used, you can view and download the camera's picture, you can also remotely shoot the camera, with a mobile phone but also wireless shutter Why
Settings Click the three points in the upper right corner to enter the settings page, including the memory card settings, photo location information settings, and resize settings. If there are two cards, you can easily switch between them.
You can also sync your phone and camera time, eliminating manual settings
Click on the image on the camera on the main interface to enter the preview mode
Click on a picture to see a more detailed list of parameters
Rate photos from 0 to 5 stars
Point to open remote real-time display, found that the phone can be adjusted to adjust the parameters of the real-time viewfinder, aperture, shutter, light can be adjusted, this is a few streets better than the N's WMU.
Click on the screen to focus
If the distance is too close, the focus will fail
Photo real-time preview of the current parameters under the circumstances, because the C machine is the largest aperture before pressing the shutter focus, you must press the fuselage preview to view the current situation, with the app is not so much trouble, by the way can let the ground when the foot Stand, no longer have to worry about low-angle viewing.
Camera control C's machine is very easy to use on the camera, but I have not used it before trying to introduce the app.
Tap the camera button at the top of the screen to control the camera to automatically switch to camera status.
The bottom of the screen can switch sharpness, 5D4 supports 4K recording.
Microphone speaker settings
AI Servo Focus
Color temperature setting
Focus mode and focus area settings
The function of the app is quite powerful, but wifi is very power-consuming. In 2 hours, the camera turns from full power to 20%. WiFi is good, but don't forget to bring spare batteries.
Thank you for being able to see the valued friends here. This is the most serious piece of original writing. It is because the previous article has valued the quality of Auntie’s original question, and it is inconsistent with Aunt Zhang’s mother.
Purchase link Canon EF 24-70mm f/2.8L II USM Standard Zoom Lens 11999 Canon's Full-Frame Ultimate Mirror Huang Jingdong Direct Links Encyclopedia 
B+W uv mirror filter 82mm UV mirror XS-PRO ultra-thin multilayer nano-coated UV mirror protection mirror 860 yuan Jingdong direct link 
Digital Master Daisee PRO DMC SLIM Thin Digital Multi-layer Coating Polarizer CPL 82mm470 yuan Jingdong direct link 
France Gao Jian cokin Z series creative filter blue gradient mirror Z123S soft transition 690 yuan Jingdong direct link 
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Drivers with dimming capability can dim the LED light output over the full range from 100% to 0%. Dimming drivers can dim LEDs by reduction in the forward current, pulse width modulation (PWM) via digital control, or more sophisticated methods. Most dimming drivers operate using the PWM method. With this method, the frequency could range from a hundred modulations per second to as high as hundreds of thousands of modulations per second, so that the LED appears to be continuously lighted without flicker.
At present, the most commonly used LED dimming power: LED thyristor dimming power, LED 0 / 1-10V dimming power, PWM dimming power supply. Other dimming works by controlling the current and voltage, the frequency of the output to achieve the LED dimming function.
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