Professional digital SLR? Consumer digital card machine? . .
Although the operational capabilities/SLR image quality than the consumer digital cameras — specifically consumer digital card machine than better, but the volume is too big, not too easy to carry. While the consumer digital card machine and strengths and weaknesses.
The following information from the Internet:. .
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SLR cameras. .
SLR is a SLR, slr (single lens reflex).
SLR digital camera refers to single-lens reflex digital camera, that is, Digital Digital, Single alone, Lens Lens, Reflex reflective abbreviation DSLR. Present a common digital SLR camera market brands: Nikon, Canon, Pentax, Fuji, etc.. .
Working principle:.
SLR digital cameras in the system of work, the light reaches through the mirror lens, the refraction to the top of the focusing screen and to form images, and five through the eyepiece prism, we can see in the viewfinder, the scenery outside . In contrast, the general digital camera LCD screen or only through the electronic viewfinder (EVF) to see the images taken. Clearly see the image directly than by processing the image to see more conducive to filming. .
In DSLR photography, when you press the shutter button, the mirror will go on up, sensitive components (CCD or CMOS) in front of the shutter curtain will open at the same time, through the lens of light projected onto the original photographic emulsions, and then immediately after the reflector restitution, viewfinder again you can see in the image. Single-lens reflex cameras of this building, it is completely through the lens-focus shots for the viewfinder to see images and footage on forever, its scope and the actual filming camera range basically agreed that a Visual composition.
Main features:. .
SLR digital camera with a great feature is you can swap different specifications of the camera, this is the natural advantages of SLR cameras, digital camera is incomparable.
In addition, digital SLR cameras are now positioned in the high end digital camera, digital camera photography in the relationship, therefore the quality of the light-sensitive device (CCD or CMOS) area on the digital SLR is much larger than the size of ordinary digital camera, which makes the SLR digital camera for each pixel of the photosensitive area is far greater than the average digital camera, so each pixel can also show a more detailed range of brightness and color to photographic quality digital SLR cameras was significantly higher than normal digital cameras. .
http://publish。.it168。.com/cWord/3527。.shtml。.
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Canon EF 28-105mm f/3.4. .5 .5-USM standard zoom lens.
Goods Summary:. .
· Compact wide-angle zoom lens, the weight is only 370 grams, easy to carry.
* Two telescopic lens to avoid blocking built-in flash coverage. .
· Zoom, multiple mirror group of mobile, so that the lens focal length range in the best image performance.
Detailed Specifications:. .
· Mirror group structure: 12 group 15 tablets.
* Shooting range: 0. .5 M ~ ∞. .
· Maximum magnification: 0. .19 times.
* Filter diameter: 58mm. .
· Hood: EW-63 II (purchased separately).
* Dimensions (diameter × length): 72 × 75mm. .
· Weight: about 375 grams.
400D with this lens can be, but the focal length to × 1. .6 Coefficient, which is equivalent to 45-168 lens, no wide angle, but not outside the old section of the lens coating for digital SLR to optimize image quality on a slightly worse, but the effect is not too large. Note glare. .
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On the digital SLR camera lens. .
■ Wu party.
"Camera" 2005 09. .
1. image sensor size and lens focal length.
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Since the launch of digital single lens reflex cameras, since it's image sensor (CCD or CMOS) mostly only traditional 135 camera negatives, so half of the lens focus narrow perspective. Therefore, the original single-lens reflex camera with lens are in accordance with the digital camera image sensors of different length of the diagonal multiply by different coefficients in order to be equivalent to the original film camera lens focal length. Canon's 1D and 1D MARK Ⅱ image sensors larger point (28.7 mm × 19.1mm), as long as the lens focal length multiplied by the coefficient of 7.3, then a 17 ~ 35mm lens equivalent to 22-45mm focal length , wide-angle end of the conflict in the not too prominent. But the Canon 20D, 300D, 350D and other models of cameras, CMOS size is 22.7 mm × 15.1mm, we must multiply the coefficient of 1.6, so 17-35mm focal length lens into a 27-56mm, wide-angle end perspective on the people feel less broad.But Nikon, Fuji, Konica Minolta, digital SLR is the size of the image sensor 23.7mm × 15.7mm around the lens focal length multiplied 7.5 times. In this way, the original 17 — 35mm lens, equivalent to 26 — 53mm focal length. Shima SD10 digital camera and image sensor size only 20.7mm × 13.8mm, lens need to be multiplied by 7.7 times, this 17-35 lens turned 29 — 60mm. So, for those who often need to use a wide man, this segment of the lens focal length than the original 17 ~ 35mm lens angle too big a difference. .
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2. Respond to ultra-wide angle lens digital camera. .
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Digital SLR camera for wide-angle lens wide enough, many cameras, lens manufacturers have all introduced the corresponding wide-angle zoom lens. Sigma is probably the earliest in 2001 launched 14mm F2.8 and 15-30mm F3.5 ~ 4.5 E × DG two film cameras and digital cameras for simultaneous use of ultra-wide-angle lens. As these two digital camera lens broadens angle of view, they immediately became a public wide-angle lens digital SLR camera a better choice.Because this lens 14mm multiplied by the coefficient 1.5 times, focal length still reached 21mm; 15 — 30mm lens has become one of the 23 — 46mm digital camera, don't underestimate the wide angle end only widened 3 ~ 4mm focal length, but for indoor shooting has brought great convenience. Also, it's only 15 ~ 30mm lens, although somewhat yellowish color reproduction, but Aperture received 5.6, its ability to distinguish can be compared to Nikon professional lens. So, after many journalists that have purchased these lenses need to replace and supplement the original million or so 1 7 ~ 35mm F2.8 professional lens. 14mm F2.8 This lens is also continually lower prices of digital camera case, from the original 4,000 yuan rose to 6,000 yuan now. .
In December 2002, the Nikon company officially announced a new designed for Nikon d-series digital SLR cameras designed AF-S DX12-24mm F4.O G ED Digital lens (Figure 1), making it an affordable digital SLR camera of the camera lens to achieve the equivalent of 135 film camera 18 ~ 36mm ultra wide-angle zoom lens, though, it's in the wide angle end distortion is large, has been criticized by some users, but it makes digital camera also has a traditional camera 17mm lens angle of view so that digital camera users from wide angle is not enough. The same time, the camera manufacturers can focus on the development of digital image sensor APS size cameras, for other manufacturers to develop digital cameras opened the first of its kind dedicated. Soon, Sigma also introduced a free book film and digital cameras 12 ~ 24mmF4.5-5.6DGASP/HSM zoom lens (Figure 2).Although, as a mirror of the shima lens material original reputation is not very good, but so much perspective, and in recent years, the mirror as material improvements, plus it can be used with film cameras and digital cameras, image quality is also good, the price is cheaper than the Nikon 2000 Yuan, so a listing that has attracted many users. 2004 August Canon announced a dedicated to digital camera EF-S10 ~ 22mmF3.5 ~ 4.5 USM lens (Figure 3), with 20 d equivalent focal length is 16 ~ 35mm. September 2004 Tamron has introduced SPAF 11-18mm F4.5-5.6 DiII LD Asp lens; Sigma this year launched a 70 ~ 20mm F4-5.6 digital-specific lenses (Figure 4); recently Figure Korea's AT-X 12 ~ 24mm F4 are quietly listed the price at 4,650 yuan (Figure 5).Because the tuli materials of AT-X lens, lens, all-metal material, work is also quite good, it is estimated that will win many markets, but it does not use ultrasonic motor, it is said that when the noise was a bit out of focus, may in some people's heart enough. In this way, several major camera manufacturers and camera manufacturers have ultra wide-angle zoom lens that basically solved the wide angle lens digital SLR camera is not extensive.
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3. a dedicated digital camera wide-angle zoom lens in jiaoduan.
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As Canon, Nikon D70s 350D, D50, amateur level digital camera introduced, many manufacturers also has 18 — 55mm F3.5 ~ 5.6 dedicated lenses for digital single lens reflex cameras, to cover the original 28-135 film camera lens blank 80mm segment, with low-priced attract amateur photography enthusiasts. These lenses are matching with Canon 300D EF-S18 ~ 55mm F3.5-5.6; and 350D supporting the EF-S18 ~ 55mm F3.5-5.6 Ⅱ: there is introduced with the Pentax * istDS SmcPentax-DA18 ~ 55mm F3.5-5.6AL; a Nikon D70s and D50 with the launch of the AF-S DX18-55mm F3.5-5.6G ED. Most of yuan in 1600 prices.There are Nikon D70 together with launch of 18 — 70mm F3.5 ~ 4.5 lens (Figure 6) (price about $ 700 in 3), and the Canon 17-85mm F4 USM lens ~ 5.61S (Figure 7) (price about $ 5500). This is equivalent to 27-105mm segment has.
However, these digital camera terms, there exists the problem of a smaller lens aperture, and the original 17-35mm F2.8 lens aperture is smaller than many. On the 10 ~ 24mm focal length lens in paragraph, the current Nikon and Tokina only two lens aperture is constant F4; Sigma, Tamron are F4.5-5.6.While that single lens reflex digital camera speed can reach more than noise control IS01600 also has been greatly improved, but use a wide-angle lens is mostly in the light of the situation is not too good of a small indoor, Aperture, shutter speed would be difficult to improve, for some dynamic scene it will be difficult to use natural light photography; if you use Flash lighting, Flash sync speed too slow, while in the background light, but the main image of the ghost would be more obvious; Flash too fast, the principal is clear, but the background of natural light does not go in, dark a comfortable, so the aperture F5.6 in actual use will bring a lot of inconvenience, particularly to photojournalists, . Therefore, the focal length lens manufacturer broke after less extensive and difficult, should try to solve the aperture problem is too small. For manufacturers, the fact this is not a very difficult problem, may be worried that the issue price and market outlets. However, in July 2003, the Nikon D2H with the market introduction of the AF-S DX17-55mm F2.8G IF-ED and NikkorAFDX Fisheye10.5mm F2.8G ED two large aperture lens.Although the price a bit high, but let people have a choice of room, and 17 — 55mm F2.8 one lens, there are still many people purchased. Of course, for amateur photographers, Aperture smaller, means that the price can be cheaper.
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4. the telephoto lens on a camera on the advantages.
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There is a wide enough range of digital cameras disadvantages at the same time, there is also a contributing factor in the telephoto end. If a F2.8 lens 200mm multiply by 1.5 coefficient, is equivalent to a 300mm F2.8 lens. You know, a traditional 300mm F2.8 lens price is 80 — 200mm F2, 8 3 times above the lens, the weight of more than 1 times, most recently focusing distance, lens 2 300mm. .2m around 80 ~ 200mm in 1.5m F2.8 lens. If the 300mm F2.8 lens mounted on a DSLR, the equivalent of a 450mm F2.8 lens, the price of the same focal length lens than the cheaper, light weight, will be many, such a result is the original photographer can not imagine the luxury. So many camera manufacturers insist on development of image sensor APS size digital camera, not only reduce production cost side, but also like the side of the user.Just like the Nikon D2X in the CMOS dimensions unchanged to the actual pixel reached 1240 million, but image quality is also good, you can also use quick cutting pattern to achieve eight pieces per second shooting speed and makes the lens focus can be multiplied by 2 times the price of the whole picture than the Canon 1Ds M A R K Ⅱ cheap one third. Therefore, as long as a suitable lens developed, it would be single lens reflex digital camera users are welcome.
