National Geographic magazine classic cover "Afghan Girl" is my favorite work. It was shot by Steve McCurry using Nikon FM2 + Nikkor Ai-S 105mm F2.5. Her look is meaningful, and her eyes are filled with curiosity and discreetness and with fearful eyes, like the look of your soul.
This lens version is numerous, is the evergreen tree of the Nikon family. The production year is very long and many changes have been made. Cm version-->auto early version-->auto late version-->auto P·C-->k type version-->AI version-->The early white mouth structure of AIS version is sonnar, starting from the latter part of AUTO It is Xenotar structure. I bought the P·C Auto version because the auto version is a metal aperture ring and metal focus ring, excellent workmanship, solid feel, and good coating. The auto version changed the AI ​​port, and it can achieve automatic metering of the A file. “C†means the use of a new multi-layer coating, which can further improve the anti-glare ability, color performance is also theoretically better, more sought after in the secondary market. The body is using the Nikon D750, the fuselage set old lens parameters can output exif information intact.
Lens focal length: 105mm fixed focus maximum aperture: F2.5
Minimum aperture: F22/F32 (depending on the version, the minimum aperture F22 of the AI-S version used by Steve at the time of shooting)
Lens structure: Xenotar (5 pieces of 4 groups), Sonnar (5 pieces of 3 groups, early)
Aperture Blade: 7 pieces The closest focusing distance: 100cm
Maximum magnification: 0.130
Filter aperture: 52mm
Nikon 105mm 2.5_ Taobao search Taobao search is the most intelligent product search engine, through the operation of big data, accurate understanding of goods and users, providing accurate personalized search experience. Direct links to s.taobao.com Simple feeling
1, good open sharpness, out of focus is also soft enough
2, the resolution can afford 20 million pixels D750
3, due to too much production, second-hand prices are very reasonable, and now the market price is about 1K, playing very well
4, all-metal material, excellent workmanship, focus damping is very good, there is a sense of lubrication, nothing likes to lap a few times
5, rumors Nikon's most German flavor of the lens, personal style problems did not feel
6, the color is very different from my Sigma 35art
7, focusing stroke is very long, but also to pay attention to that small Ding point coke lights, shooting a bit difficult
8, auto version into ai mouth mounted on my F3 film machine viewfinder can not see the aperture value
The following is the shooting in the D750
Two small plants on the wall are more difficult to find
I saw a man who looks a little Japanese.
Huanong’s bike parked for a long time
It's difficult to capture dynamics
The front of the bike stopped suddenly to shoot the lotus
Instructing models
Roadside flowers are usually difficult to detect when passing by
Coincidentally, that day was a freshman in military training
Paste the same scene shot with F3HP+105mm+agfa200.
Baidu to the last version of the difference
1. The version of the public
It will be called the public version because the early nikon lens marks the focal length in cm, and the sign of the mirror at that time was Nippon Logaku Japan No. xxxxxxx Nikkor-P.
Auto 1:2.5 f = 10.5cm
Regarding the significance and evolution of the lens designation code, here is a brief discussion
The mirror group of the first-generation mirror is a five-piece, three-group sonnar type with no screws at the bottom of the mirror and belongs to the class A mirror.
The serial number is about 120xxx~15xxxx. Production starts from 1959
2.auto early edition
The reason for this name is just for convenience, not accurate, in fact, the public version also has auto function, on behalf of the lens in the focus and metering can open the aperture, and will automatically shrink to when shooting
Specify aperture
The auto version is still a five-segment sonnar design, which is the same as the public version.
The initial auto version was the same as the public version. The mirror tail had no screws. However, the maintenance was very inconvenient. Therefore, five screws were used in the later period. Similar designs have been used in AF mirrors.
In addition to the change in the tail of the mirror, the aperture ring is also changed to a gear-shaped protrusion in the later period to increase the convenience of handling and operation. This design is used in the PC version.
The serial number of the auto plate from about 15xxxx~28xxxx~?, produced until 1971
3.auto late version
The most concerned about the mirror design change occurred in this edition; from the original five three groups sannar type to five four groups Xenotar type (or double Gaussian deformation)
Since the lenses maintain a five-piece design, the code is still used auto-p, p is the meaning of five lenses
In addition, the minimum aperture is also changed from f22 to f32
The difference between the appearance and the previous version is that the lens body between the aperture ring and the focus ring is changed from the original silver coating to black, but still retains the silver ring marking the aperture
The serial number of the auto late plate is about 40xxxx~47xxxx, produced between 1971 and 1973
4. pc version
This version is the most famous and widely circulated is the same type of Afghan girl
However, some sources pointed out that when the body used by Steve McCurry was FM2, the chances of using a PC version would be insignificant.
With the conclusion of the same friend, Steve should use an AI or AIS mirror, and the AIS is most logical and has the highest probability.
The main difference between the PC version and the previous version is the use of anti-reflection multilayer coating (Nikon Integrated Coating, NIC)
Aperture ring has two versions of gear and diamond
The serial number of the PC is about 500001~57xxxx, which was produced between 1973 and 1975.
5.K version
K-type mirror is the predecessor of AI mirror, basically designed the same as PC version
The main difference in appearance
The rubber ring is changed from the metal gear shape to the long rubber, the aperture ring is made of diamond-shaped protrusions, and there is no auto word on the label.
The K version is approximately from 67xxxx to 72xxxx, produced between 1974 and 1977
6.AI version
The change of the AI ​​mirror itself will not be described
It is worth mentioning that the minimum aperture is changed from AI and f32 is changed back to f22.
Production serial number between 74xxxx~88xxxx, produced between 1977 and 1981
7.AIS version
AIS is the last version and is the oldest version (about 24 years)
A more special change is the addition of a built-in hood with a minimum aperture maintained at f22
Product Description
SPD Surge Protective Device,Lightning Surge Protector
Surge Protection Device (SPD)
It is a device used to limiting instant surge voltage and discharge surge current, it at least including a non-linear component.
Surge protective Device Model Selection
With the impact of international information flow, the rapid development of microelectronic science and technology, communication, computer and automatic control technology, make the building start to go for high quality, high functional area, formed a new building style-intelligent building. As inside the intelligent building there are lot of information system, <<Building lightning protection design norm>> GB50057-94(2002 vision)(hereafter brief as <<lightning protection norm>>) put forward the relative requirement to install the surge protective device, to ensure the information system safely and stable running.
SPD essentially is a equipotential connection material, its model selection is according to the different lightning protection area, different lightning electromagnetic pulse critical and different equipotential connection position, decide which kind of SPD used in the area, to achieve the equipotential connection with the common earth electrode. Our statement will based on SPD's maximum discharge current Imax, continuous operating voltage Uc, protection voltage Up, alarm mode etc.
As per << Lightning Protection Norm>> item 6.4.4 stipulation "SPD must can withstand the expected lightning current flow and should confirm to the additional two requirements: the maximum clamp voltage during surge across, capable to extinguish the power frequency follow-on current after lightning current across." That is the value of SPD's max. clamp voltage add its induction voltage of two ends should be same with the system's basic insulation level and the equipment allowed max. surge voltage.
SPD for Power Supply System Series Selection Guide
The installation of SPD at each lightning protection zone, according to the standard of low voltage electrical appearance, make classification of electrical equipment in accordance with the over voltage category, its insulation withstand impulse voltage level can determine the selection of SPD. According to the standard of low voltage electrical appearance, make classification of electrical equipment in accordance with the over voltage category as signal level, loading level, distribution and control level, power supply level. Its insulation withstand impulse voltage level are:1500V,2500V,4000V,6000V. As per to the protected equipment installation position different and the different lightning current of different lightning protection zone, to determine the installation position of SPD for power supply and the break-over capacity.
The installation distance between each level SPD should not more than 10m, the distance between SPD and protected equipment should as short as possible, not more than 10m. If due to limitation of installation position, can't guarantee the installation distance, then need to install decoupling component between each level SPD, make the after class SPD can be protected by the prior class SPD. In the low voltage power supply system, connecting an inductor can achieve the decoupling purpose.
SPD for power supply system specification selection principle
Max. continuous operating voltage: bigger than protected equipment, the system's max. continuous operating voltage.
TT System: Uc≥1.55Uo (Uo is low voltage system to null line voltage)
TN System: Uc≥1.15Uo
IT System: Uc≥1.15Uo(Uo is low voltage system to line voltage)
Voltage Protection Level: less than the insulation withstand impulse voltage of protected equipment
Rated discharge current: determined as per to the lightning situation of the position installed and lightning protection zone.
SP1 Series
Normal Working Conditions
-Altitude not exceed 2000m
-Ambient air temperature:
Normal range: -5ºC~+40ºC
Extend range: -40ºC~+80ºC
-Relative Humidity: 30% - 90% under indoor temperature condition
- At the place without obviously shaking and shock vibration
- Non-explosion danger medium, non-corrosion gas and dust ( including conductive dust)
Classification
-As per Nominal Discharge Current:
5,10,20,30,40,60KA(8/20µs)
- As per Maximum continuous operating voltage:
275V,320V,385V,420V,440V,460V
- As per to poles
1P,1P+N,2P,3P,3P+N,4P
- As per auxiliary functions:
a. With remote signal output ( remote alarm function)
b. Without remote signal output
Selection Principle
- The continuous applied voltage on the two terminals of SPD should not more than the maximum continuous operating voltage Uc value;
- The voltage protection level Up of SPD should less than the maximum impulse withstand voltage of the protected equipment;
- As per to the different earthing system and protection mode to select the specification accordingly;
Product Features
1, built-in over-current overheating, temperature control circuit technology.
2, the module design, easy installation, online replacement.
3, low leakage current, fast response time, low residual voltage.
4, alarm indication device, green (normal) v red (fault).
| Model/Technical Parameters | WR-B60 | WR-B80 | WR-B100 | WR-B120 | WR-B150 |
| Rated Operating Voltage Un (V ~) | 220V 380V | 220V 380V | 220V 380V | 220V 380V | 220V 380V |
| Maximum Continuous Operating Voltage Uc (V ~) kV | 385V 420V | 385V 420V | 385V 420V | 385V 420V | 385V 420V |
| Voltage Protection Level Up (V ~) kV | ≤1.8≤2.2 | ≤2.4≤2.5 | ≤2.5≤3.2 | ≤3.4≤3.7 | ≤4.0≤4.5 |
|
Maximum Discharge Current Imax(8/μ20μs)kA |
60 | 80 | 100 | 120 | 150 |
|
Nominal Discharge Current In(8/μ20μs)kA |
30 | 40 | 60 | 80 | 100 |
| Response Time | <25 | <100 | |||
| L/N(mm²)The Cross Section Of L/N Line | 16,25 | 16,25 | 16,25 | 16,25 | 25,35 |
| PE (mm²)The Cross Section Of PE Line | 16,25 | 25,35 | 25,35 | 25,35 | 35 |
| Fuse or Switch (A) | 63A | 63A | 63A,100A | 63A,100A | 63A,125A |
| The Line Section of Communication and Alarm (mm²) | ≥ 1.5 | ||||
|
Operating Environment-C |
(-40ºC~-+85ºC) | ||||
| Relative humidity 25 ºC | ≤95% | ||||
| installation | Standard Rail35mm | ||||
| Material of Outer Covering | Fiber Glass Reinforced Plastic | ||||
Surge Protector SPD,Surge Protection Device SPD,SPD
Wenzhou Korlen Electric Appliances Co., Ltd. , https://www.zjaccontactor.com