数码变焦,英文名称为DigitalZoom,是通过数码相机内的处理器,把图片内的每个象素面积增大,从而达到放大目的。
这种手法如同用图像处理软件把图片的面积改大,不过程序在数码相机内进行,把原来CCD影像感应器上的一部份像素使用"插值"处理手段做放大,将CCD影像感应器上的像素用插值算法将画面放大到整个画面。实际上数码变焦并没有改变镜头的焦距。原理:利用软件对已有像素周边的色彩进行判断,并根据周边的色彩情况插入经特殊算法加入的像素。
焦距是镜头光心到成像平面的距离,变焦,就是改变这个距离,差别是视角的改变,视角小了,被拍物体在画面上占的面积大,我们就说是放大了。反之广角镜头的视角大,画面中目标物体就显得小。数码相机的变焦,就是通过改变视角来放大、缩小画面。 但是,在一定价格的前提下,强求大倍数变焦是不可取的,首先镜头增大倍数,会导致顾此失彼,其次还有厂商推出的数码变焦,就是在画面上截取放大,完全没有意义。
光学变焦 依靠光学镜头结构来实现变焦,变焦方式与传统相机设计一样,取决于镜头的焦距,是通过摄像头的镜片移动来放大与缩小需要拍摄的景物。光学变焦倍数越大,能拍摄的景物就越远。光学变焦可以支持图像主体成像后,分辨率及画质不会改变,相对清晰。数码变焦 实际上是画面的电子放大,把原来CCD影像感应器上的一部份像素使用“插值”算法将画面放大。通过数码变焦,拍摄的景物放大了,但它的清晰度会有一定程度的下降,类似与VCD或DVD中的zoom功能,只能将原先的图像尺寸裁小,让图像在LCD屏幕上变得较大,但并不会使细节更清晰,相机的最大变焦不是数字变焦和光学变焦的乘积,是相加。W290是款普通的家用机。质量不错,只要伸缩镜头不出问题可以用很久。
如果想用100倍数码变焦拍照片,成片质量肯定非常一般,说到底100倍数码变焦噱头大于实用。
数码变焦不是一个新鲜的技术概念,十多年前的卡片机、家用DV(数码摄像机)标配数码变焦,而且动不动就上百倍。现在家用DV基本都不提数码变焦,单反相机更是拒绝和数码变焦沾上关系,简单说数码变焦这个卖点被无情抛弃了。
什么相机啊?卡片机应该没有手动对焦功能,也就不能取消自动对焦。
单反上一般在镜头左面有个类于开关机的小手柄,标记:AF/MF MF就是手动对焦了 镜头上可能也有,标记一样数码相机变焦是一种功能,利用它,相机可以调整镜头的焦距以使拍摄的物体从远到近或者从近到远变得清晰和清晰,而不必真正移动相机或物体。这使得用户可以更轻松地拍摄各种距离的物体,并更接近你所希望的照片效果。
数码相机依靠光学镜头结构来实现变焦。数码相机的光学变焦方式与传统35mm相机差不多,就是通过镜片移动来放大与缩小需要拍摄的景物,光学变焦倍数越大,能拍摄的景物就越远。
10倍的光学变焦的镜头的焦距范围一般是
36-360mm,也有28-280mm的。也就是说最大焦距为最小焦距的10倍。
不存在120倍光学变焦数码相机。
光学变焦的倍数的计算是镜头的最长焦段除以最广角段,比如17-200mm的镜头就是200除以17,约12倍变焦。如果光学倍焦倍数很大,可以在不改变拍摄距离的情况下以拍到人物的远景、全景、中景、近景、特写等画面。用到影视摄影上,还可得到连续变焦效果的画面。
一般来说,焦距在24mm~35mm之间的镜头属于“广角镜头”,它们具有较小的焦距和较宽的视角,可以收录更广阔的空间,因此常被业内誉为“大师镜头”。
历史上焦距最长的镜头焦距2米,实际变焦也就3倍,重近20公斤。即使除以广角焦距24mm,倍数也不到100。没有这样的镜头。
数码相机的变焦功能包括光学变焦与数字变焦的2种类型。光学变焦是通过改变CCD与透镜的焦点距离来放大图像的。其基本结构与银盐相机的变焦相同。数字变焦采用了与光学变焦截然不同的结构。
数字变焦有多种方式,其中最普通的是提取CCD拍摄到图像的局部,并通过数字处理来扩大图像的方式。
但是,在这种方式下,进行修饰处理时总会出现图像画质恶化的现象。
因此,在配备光学、数字两种变焦的相机中,只有在把图像放大到光学变焦无法完成的范围时,才会使用数字变焦。
目前,各相机制造商正在开发减少图像恶化的技术,并配备在自己的产品中。
另外,图像放大后,用户在个人电脑上处理时就会即费功夫又耗时间。由于数字变焦在拍摄时能够自动进行上述处理,因此相当方便。
另外,在数字变焦中,也有象富士胶卷“FinePix”系列那样的虽然分割图像但不进行放大的类型。
用处不大只是把图片放大了。
在一定范围内的数码变焦还是比较清晰的,但是一旦超过一个范围之后数码变焦就不如在电脑上把照片放大使用了,数码变焦就是相当于在电脑上把照片放大。数码变焦,是把感应器上的部分信号,利用软体演算法,根据图元点周边图元,经过推算,把图片内的每个象素面积增大,从而达到放大目的。它的缺点是造成画质下降。但是插值演算法和相机硬体都在发展,现在一些数码相机经过数码变焦后的照片也能保证相当的清晰度,但是和光学变焦得到的图片还是不能比。
Digital scorch, english name is DigitalZoom, it is to pass the processor inside digital camera, increase every acreage elephantine element inside the picture, achieve enlarge goal thereby.
This kind of gimmick changes the area of the picture as handling software with image big, nevertheless the program undertakes inside digital camera, use " interpolation " what get on original CCD video inductor to handle a method to do enlarge like element partially, get on CCD video inductor use interpolation algorithm to magnify the picture to whole picture like element. Actually digital scorch did not change the focus of camera lens. Principle: ? of bud press and smooth breaks a drum used in the army in ancient China of Piao of the Ge that delay Xing to knock at accept type to believes discharge? and insert what join via special algorithm to resemble element according to circumjacent colour circumstance.
Focal length is camera lens light the heart is apart from to what become image plane, scorch, change this distance namely, the difference is the change of the perspective, the perspective is little, the area that the object that be patted occupies on the picture is large, we say is enlarge. Conversely the perspective of wide-angle lens is big, object of the target in the picture appears small. The scorch of digital camera, come through changing a perspective namely enlarge, contractible picture. But, below the premise of fair value, importuning big diploid scorch cannot be taken, above all camera lens increases multiple, can bring about attend to one thing and lose another, still have the digital scorch that the manufacturer rolls out next, magnify in the intercept on the picture namely, complete no point.
Optical scorch relies on structure of optical camera lens to realize scorch, scorch means and traditional camera design are same, depend on the focal length of camera lens, be through photographing the lens that resembles a head shift comes enlarge and the scenery that narrow need films. Optical scorch multiple is bigger, the scenery that can film is further. Optical scorch can support image principal part to become after resembling, resolution and picture won't be changed character, relatively clear. Digital scorch is the electronic enlarge of the picture actually, use original CCD on video inductor like element partially " interpolation " enlarge of algorithm general picture. Pass digital scorch, filmed scenery magnified, but the fall that its definition can have fixed rate, similar with the Zoom function in VCD or DVD, can reduce original image size only small, let image become bigger on LCD screen, but can not make details clearer, the biggest scorch of camera is not the product of digital scorch and optical scorch, it is addition. W290 is an average family expenses machine. Quality is good, want adjustable camera lens not to give a problem to be able to be used only very long.
If want to pile up scorch to take a picture with 100 multiple, become a quality affirmation is very general, stunt of scorch of 100 times number is more than in the final analysis practical.
Digital scorch is not a new technical idea, DV of the card machine more than 10 years ago, family expenses (digital camera) mark matchs digital scorch, and go up easily hundredfold. Family expenses DV does not carry digital scorch basically now, sheet turns over camera is to reject to touch a concern with digital scorch more, say digital scorch sold a dot this to be abandoned by callosity simply.
What camera? Card machine should use pair of anxious functions without the hand, irrevocable also be opposite automatically anxious.
Sheet is turned over go up to have in camera lens left commonly kind of small handle at switch machine, mark: AF/MF MF is the hand is moved right anxious the likelihood on camera lens also has, number is sameDigital camera scorch is a kind of function, use it, the object that camera can adjust the focal length of camera lens to film in order to make from prep so far as close or from arrive nearly far become clarity and clarity, and need not move truly camera or object. This makes an user OK film easily the object of all sorts of distances, be close to the photograph effect that you hope more.
Digital camera relies on structure of optical camera lens to realize scorch. The optical scorch means of digital camera and traditional 35mm camera are about the same, come through lens shift namely enlarge and the scenery that narrow need films, optical scorch multiple is bigger, the scenery that can film is further.
The focal length limits of the camera lens of the optical scorch of 10 times is commonly
36-360mm, also have 28-280mm. That is to say 10 times what the biggest focus is the smallest focal length.
120 times more nonexistent camera of optical scorch number.
The diploid computation of optical scorch is camera lens is the longest anxious paragraph divide with the most extensive role paragraph, for instance the camera lens of 17-200mm is 200 divide with 17, make an appointment with 12 times scorch. If times more optical anxious multiple is very big, can not changing the picture such as the distant view that films the person reachs with patting below the circumstance of the distance, panoramic, medium shot, close shot, close-up. Use to photography of movie and TV, return the picture of effect of attainable successive scorch.
Generally speaking, focal length is belonged to in the camera lens between 24mm~35mm " wide-angle lens " , they have lesser focal length and wider perspective, can collect vaster space, accordingly constant by course of study inside praise for " Great Master camera lens " .
The camera lens focal distance with the longest focal distance on the history 2 meters, actual scorch also with respect to 3 times, weigh nearly 20 kilograms. Although divide with 24mm of extensive role focal length, multiple also is less than 100. Without such camera lens.
The 2 sort that the scorch function of digital camera includes optical scorch and digital scorch. Optical scorch is to pass the focal distance that changes CCD and lens to magnify of image. Its are basic the scorch of structure and silver-colored salt camera is identical. Digital scorch used as disparate as optical scorch structure.
Digital scorch has a variety of kind, among them prevailing is to extract CCD to film of image local, enlarge the means of image through counting word processing.
But, below this kind of means, image always can appear to draw the phenomenon of qualitative aggravation when undertaking got-up handling.
Accordingly, in provide optical, number in the camera of two kinds of scorch, it is only when the limits that cannot finish zoom to optical scorch, ability can use digital scorch.
Current, each camera manufacturer is developing the technology that reduces image aggravation, in providing the product in oneself.
Additional, after zoom, the user can expend kongfu to be cost again namely when be handled on personal computer. Because digital scorch can undertake afore-mentioned processing automatically when film, because this comparatives,go to the lavatory.
Additional, in digital scorch, also have elephantine Fuji film " FinePix " series in that way although break up image but the kind that does not have enlarge.
Good just magnified the picture not quite.
The digital scorch inside certain limits is clearer still, but once digital scorch is inferior to going up to magnify the photograph in computer after a limits,used, digital scorch is equivalent to magnifying the photograph on computer namely. Digital scorch, it is the partial signal that gets on inductor, use software figure method, the basis pursues yuan of dot periphery graph yuan, the course is computative, increase every acreage elephantine element inside the picture, achieve enlarge goal thereby. Its defect is to cause a picture to drop character. But strong put oneself in another's position of interpolation figure law and camera is developing, the photograph after camera of a few numbers passes digital scorch now also can assure the definition that comparative, but the picture that gets with optical scorch still cannot be compared.