ios 获取相机胶卷_电影胶片相机的工作原理

ios 获取相机胶卷

We’ve become reliant on digital cameras since they are so easy to use. But have you ever wondered how film-based photography works? Read on to increase your photographic knowledge—or to develop an new appreciation for your point and click camera.

由于它们非常易于使用，因此我们开始依赖它们。但是您是否想知道基于胶片的摄影如何工作？请继续阅读，以增加您的摄影知识，或者对您的观点和单击照相机有新的认识。

Film-based cameras, to some, are a relic of the past. Simply an old technology made obsolete by the new and improved. But to many, film is an artisan’s material, and a photographic experience no digital system could hope to ever recreate. While many photographers, professional and amateur will swear by the quality of both film-based or digital cameras—the fact remains that film is still a valid way to take great photographs, and a fascinating way to learn more about how photography works.

在某些情况下，基于胶片的相机是过去的遗物。只是旧技术被新技术和改进技术淘汰了。但是对于许多人来说，电影是工匠的素材，而摄影经验是任何数字系统都无法希望再现的。尽管许多摄影师，专业人士和业余摄影师都会对基于胶片的相机或数码相机的质量发誓，但事实仍然是，胶卷仍然是拍摄精美照片的有效方法，也是一种了解摄影原理的有趣方法。

摄影回顾：光线，镜头和曝光元素 (Photography Recap: Light, Lenses, and The Elements of Exposure)

We’ve covered the basics (and them some) on how cameras work before, but for readers starting here (or those readers wanting a refresher), we’ll start with a tour of the basics. Cameras are, in theory, fairly simple. Modern cameras and lenses have had so many years of improvements in technology that it may seem ridiculous to call them simple, even if they use photographic film instead of incredibly advanced modern light sensors. However, despite all of these advances, all cameras have one reasonably simple goal: gathering, focusing, and limiting the amount of light that reaches some sort of light sensitive material.

我们已经介绍了相机以前如何工作的基础知识 ( 以及其中的一些 )，但是对于从此处开始的读者( 或想要复习知识的读者 )，我们将从基础知识开始。相机在理论上是相当简单的。现代相机和镜头在技术上已经取得了许多年的进步，以至于称其简单，即使它们使用照相胶片而不是令人难以置信的先进的现代光传感器，看起来也很荒谬。但是，尽管取得了所有这些进步，但所有相机都具有一个相当简单的目标： 聚集，聚焦和限制到达某种光敏材料的光量。

Cameras are all about capturing and recording an instant of time by creating some sort of chemical or electric reaction with the photons (light particles) beaming down or bouncing around in any given photographic moment. These instants of captured light are called exposures, and are controlled by three major variables known as the elements of exposure: aperture, length of exposure, and light sensitivity. Aperture refers to the amount of light blocked or allowed in by a mechanical diaphragm inside the camera’s lens. The larger the number on an aperture setting, the smaller fraction of light is allowed to the sensor. Length of exposure is calculated in seconds or fractions of a second; usually this is called shutter speed, and controls how long light sensitive materials are exposed to the light.

相机都是通过在光子(轻粒子)在任何给定的摄影瞬间向后射出或反弹的情况下产生某种化学或电React来捕获和记录瞬间的。被捕获的光的这些瞬间称为“ 曝光” ，由称为曝光 元素的三个主要变量控制：光圈，曝光时间和感光度。光圈是指相机镜头内部的机械光圈阻挡或允许的光量。光圈设置上的数字越大，传感器允许的光线越小。曝光时间以秒或几分之一秒为单位；通常将其称为“ 快门速度” ，它控制光敏材料暴露于光线的时间。

Light sensitivity, like it sounds, is how sensitive to light the photo sensitive material inside the camera actually is. Does it take a little bit of light, or a lot to create the perfect exposure? This is sometimes referred to as the “speed” of the film used. “Faster” films can capture images with less light, therefore creating proper exposures in much smaller fractions of a second. “Slower” film requires more light, and therefore longer exposure settings. Light sensitivity, often referred to as ISO, is a significant starting point, because it’s one of the first things a film photographer has to consider, while it is often an afterthought for digital photographers.

光灵敏度 ，像它的声音，是多么敏感照亮光敏材料内的相机实际上是。创建完美的曝光需要一点光还是需要很多光？有时将其称为所用胶片的“速度”。 “快速”胶卷可以用更少的光线捕获图像，因此可以在更短的几分之一秒内产生适当的曝光。 “较慢”的胶卷需要更多的光线，因此需要更长的曝光设置。光敏度(通常称为ISO )是一个重要的起点，因为它是胶片摄影师必须考虑的第一件事，而对于数码摄影师来说却常常是事后才想到的。

胶片感光度与光传感器感光度 (Film Sensitivity versus Light Sensors Sensitivity)

Digital cameras have settings for light sensitivity. These settings, often known as ISO, are numerical settings occurring in full stop values of 50, 100, 200, 400, 800, etc. Lower numbers are less sensitive to light, but allow for better detail without a lot of grain appearing in the shot.

数码相机具有感光度设置。这些设置(通常称为ISO)是数字设置，以50、100、200、400、800等的完全停止值出现。数字越小，对光的敏感度就越低，但可以使细节更好，而不会出现很多颗粒。射击。

Film cameras have an ISO standard that is very similar to the Digital camera ISO settings—in fact digital cameras use a standard based on the film sensitivity standards. Film photographers would have to plan in advance the sort of light environment they were planning on working in, and choose a reel of film sensitized to work for various ISO standard light conditions. A high ISO film setting of 800 or 1600 would be good for photographing in lower light environments, or fast-moving objects using fast shutter speeds. Lower ISO films were those usually used in bright, sunlit environments. Photographers would have to work in whole reels of the stuff; there was no adjusting ISO on the fly if light conditions changed. If you couldn’t achieve a shot by changing your other elements of exposure, you’d likely not get the shot. Changing ISO meant changing a whole reel of 35mm film, as opposed to today, where it simply means pushing a few buttons.

胶片相机的ISO标准与数码相机的ISO设置非常相似-实际上，数码相机使用基于胶片感光度标准的标准。电影摄影师必须事先计划要计划在哪种光线环境下工作，并选择适合在各种ISO标准光照条件下使用的感光胶卷。较高的ISO胶片设置为800或1600，非常适合在光线较暗的环境中拍摄，或者使用快速快门速度拍摄快速移动的物体。较低的ISO胶片是通常在明亮，日光照射的环境中使用的胶片。摄影师将不得不全盘工作。如果光线条件发生变化，则不会即时调整ISO。如果您无法通过更改其他曝光元素来拍摄照片，则可能无法拍摄。改变ISO意味着更换整个35毫米胶片卷轴，而今天，这仅仅意味着按下几个按钮。

潜在的曝光和感光度 (Latent Exposures and Light Sensitivity)

So, yes, we have established that there are various films with various levels of sensitivity to light. But why and how are these film sensitive to light in the first place? The film, in and of itself is pretty basic. It can be thought of as a transparent carrier for light sensitive chemistry, which is applied in microscopically thin sheets over this carrier spaced out over long rolls, or various other film media. (35mm is far from the only photographic format, although they are all very similar.)

因此，是的，我们确定存在各种对光敏感度不同的胶片。但是为什么这些胶卷首先对光敏感？为什么？这部电影本身就是非常基本的。可以将其视为用于光敏化学的透明载体，该载体以微薄的薄片形式应用在该载体上，并在长卷或其他各种薄膜介质上隔开。 (尽管它们非常相似，但距离35mm并不是唯一的摄影格式。)

In both color and black and white film, layers of chemistry (often silver halides) that react to light are exposed to create a “latent image.” These latent images can be thought of as pictures that are already been chemically activated, although if you looked at it, there would be no visible evidence that the exposures have been created. Latent images, once exposed, are brought to life through a developing process that takes place in the darkroom.

在彩色和黑白胶片中，都会对光产生React的化学层(通常是卤化银)被曝光以形成“潜像”。这些潜像可以被认为是已经被化学活化的照片，尽管如果您查看它，将没有可见的证据表明已经形成了曝光。潜像一旦被曝光，就会通过在暗室中发生的显影过程而栩栩如生。

暗房：使用化学方法创建图像 (Darkrooms: Creating Images with Chemistry)

Because film cameras can only create these latent images, films that have been exposed go through a process called “developing.” Developing film, for most, meant dropping off rolls of 35mm film, and getting back prints and negatives. However, there are two whole developing steps between the film drop off stage and the print stage. Let’s briefly take a look at how film is developed.

由于胶片相机只能创建这些潜像，因此已曝光的胶片将经历称为“显影”的过程。对于大多数胶卷来说，显影意味着放下35毫米胶卷，并取回胶卷和底片。但是，在胶卷送下阶段和印刷阶段之间有两个完整的显影步骤。让我们简要地看一下胶片的显影方式。

Photo films, even after being exposed, are still in a state of light sensitivity. Taking bare film out into an environment with any light in it will ruin any and all exposures, as well as making the film completle unusable. ~~To work around this, films are developed in what is known as a “darkroom.”~~ Darkrooms, unlike what you might expect, are usually not completely dark, but are lit with filtered light that films aren’t as sensitive to, allowing developers to see. A lot of films, black and white in particular, are not as sensitive to yellow, red or orange lights, so darkrooms will have colored light bulbs or simple translucent filters that fill otherwise dark rooms with tinted colored light.

摄影胶片即使曝光后仍处于感光状态。将裸露的胶片带入光线充足的环境中将破坏所有曝光，并使胶片无法使用。 ~~为解决此问题，在所谓的“暗室”中冲印了胶卷。~~ 与您所期望的不同，暗房通常不是完全黑暗的，而是被过滤后的光线照亮，胶片对光线的敏感度不高，因此开发商可以看到。 ~~许多胶片(尤其是黑白胶片)对黄色，红色或橙色的光线不那么敏感，因此暗室将使用彩色灯泡或简单的半透明滤镜，否则将在暗室中填充彩色光。~~

Edit: Films are actually developed in complete darkness in film tanks, as they are sensitive to all the whole spectrum of light. Photo papers are usually less sensitive to certain parts of the spectrum and are developed in the darkroom.

编辑：实际上，胶片是在完全暗的状态下在胶片盒中显影的，因为它们对所有光谱都敏感。 相纸通常对光谱的某些部分不太敏感，并且在暗室中显影。

Color and black and white films use different chemistry and methods, but they employ basically the same principles. Exposed films (both color, black and white) are put in baths of chemistry that chemically change the microscopic bits treated film (“grains” of photosensitive silver halide, etc). With black and white film, those areas exposed to the more light harden so that they do not wash away, while the darkest areas exposed to the least light wash away to transparent film. This creates the signature “negative” look, with light colors swapped to black and dark areas swapped to clear transparency. Once the film is developed in this first bath, it is quickly rinsed in a “stop bath,” usually just water. The third bath is a chemical “fixer” that arrests the developing process, deactivating the chemistry on the films, freezing the developed film at its current state. Unfixed film can continue to develop without being stopped fully with a bath of chemical fixer, changing the image over time. Chemical fixer is a fairly hazardous chemical, and usually negatives are washed in another basic bath of water after fixing and dried.

彩色胶片和黑白胶片使用不同的化学和方法，但它们采用的原理基本相同。将曝光过的胶片(彩色，黑白)放入化学浴中，以化学方式改变经微观处理的胶片(光敏卤化银的“颗粒”等)。对于黑白胶片，那些暴露于更多光线的区域会变硬，以致它们不会被冲走，而暴露于最少光线的最暗区域则会被透明膜冲走。这将创建标志性的“负”外观，将浅色交换为黑色，将深色区域交换为透明。一旦在第一个浴中冲洗了胶片，便会在“停浴”(通常只是用水)中快速冲洗。第三浴是化学“定影剂”，其阻止显影过程，使胶片上的化学物质失活，将显影后的胶片冻结在当前状态。未定影的胶卷可以继续显影，而不会被化学定影液完全浸没，从而随着时间的推移而改变图像。化学定影剂是一种相当危险的化学药品，通常在定影后将负片在另一个碱性水浴中洗涤并干燥。

Color films undergo a similar developing process. In order to create full color images, negatives have to be created that produce the three primary colors of light: red, green and blue. Negatives of these colors are created using another set of familiar primary colors: cyan, magenta, and yellow. Blue light is exposed on a yellow layer, while red is exposed to a cyan layer, and green to a magenta. Each layer is tuned to be sensitive primarily to photons of specific wavelengths (colors). Once exposed, latent images are developed, stopped, washed, fixed, and washed again in much the same way black and white film is developed.

彩色胶片经历类似的显影过程。为了创建全彩色图像，必须创建负片以产生光的三种原色：红色，绿色和蓝色。这些颜色的底片是使用另一组熟悉的原色创建的：青色，品红色和黄色。蓝光暴露在黄色层上，而红色暴露在青色层上，绿色暴露在品红色上。调整每个层主要对特定波长(颜色)的光子敏感。一旦曝光，就以与黑白胶片显影相同的方式显影，停止，冲洗，定影和再次冲洗潜像。

返回暗室：使用底片冲洗 (Back to the Darkroom: Printing with Film Negatives)

We’re not out of the dark yet; in order to turn a film negative into a print, more photo sensitive materials have to be bought, this time for printing. Unlike modern digital photography which is handled by digital printers, film-based printing is more or less repeating the same photographic process over again to create a true color image from a photo negative. Let’s take a quick look at what it takes to create a single film-based photographic print.

我们还没有走出黑暗。为了将胶卷底片转换成照片，这次必须购买更多的感光材料。与数字打印机处理的现代数字摄影不同，基于胶片的打印或多或少地重复了相同的照相过程，以从负片上创建真实的彩色图像。让我们快速了解一下创建基于胶片的单张照片冲印品的过程。

Film-based prints are all done on special sensitized, chemically treated papers that are sort of similar to photographic film. At a glance, they look and feel a lot like inkjet photo paper. One obvious difference in the two is that inkjet photo paper can be taken into the light—photo sensitive paper for film prints has to be worked with in the darkroom.

基于胶片的照片都是在特殊的感光化学处理纸上完成的，这些纸与照相胶片有点相似。乍一看，它们的外观和感觉非常像喷墨相纸。两者之间的一个明显区别是可以将喷墨照片纸放入光中-用于胶片拷贝的光敏纸必须在暗室中使用。

Prints can be made either by placing strips of film directly onto photo sensitive paper (ever heard the term contact sheet?) or by using an enlarger, which is basically a sort of projector that can cast light through negatives to create enlarged images. Either way, the photo paper is exposed to light, with the film blocking parts of the light and exposing others, and, in the case of color film, changing the wavelength (color) of the white light of the exposure.

可以通过将胶片条直接放在感光纸上(曾经听说过接触纸 ？)来进行打印，也可以使用放大机(基本上是一种可以通过底片投射光线以产生放大图像的投影仪)来进行打印。不论哪种方式，照相纸都被曝光，胶片会阻挡部分光线并曝光其他部分，如果是彩色胶片，则改变曝光的白光的波长(颜色)。

From there, the photo paper has its own latent image, and is developed in more or less the same manner as films, as the chemistry is somewhat similar. The only difference is that black and white/colored tones appear from the exposure when they are developed, while films are washed away to transparency when the exposed parts are developed. This is the major difference between images in photo paper and on films—photo paper gives you your finalized, naturalistic image.

从那里开始，相纸具有自己的潜像，并且由于化学性质有些相似，因此以与胶片大致相同的方式显影。唯一的区别是，黑白和彩色色调在显影时会从曝光中出现，而胶片在曝光部分显影时会被冲洗掉，变成透明。这是照片纸和胶片上图像之间的主要区别-照片纸可为您提供最终的，自然的图像。

使用基于胶片的过程创建丰富的图像 (Creating Rich Images with Film Based Processes)

Having had years to develop techniques, new chemistry, and technology, photographers have gotten very skilled at creating dynamic and rich imagery with these processes—most of which may seem almost needlessly complicated to modern point-and-shoot style photographers. These image making techniques, in the hands of skilled printers and developers, could create rich, amazing images, as well as compensating for loads of problems encountered while shooting. Did you overexpose your shots? Try underexposing your film. Is the detail in your highlights washed out and thin? Make like Ansel Adams, and dodge and burn to create better highlights and shadows.

经过多年的技术，新化学和技术开发，摄影师已经非常熟练地使用这些过程来创建动态且丰富的图像-对于现代傻瓜式摄影师而言，其中大多数似乎几乎不必要 。这些图像制作技术，由熟练的打印机和开发人员掌握，可以创建出丰富而令人惊叹的图像，并补偿拍摄过程中遇到的大量问题。您是否曝光过度？尝试使胶片曝光不足。高光中的细节是否被冲淡和变薄？像安塞尔·亚当斯(Ansel Adams)一样，闪避并燃烧以创建更好的高光和阴影。

Film photographers may have a complex, challenging method compared to shooting with digital cameras and printing from Photoshop. However, there are some artists that will likely never give up film, or perhaps those that will never work exclusively in digital. Film, with all its challenges, still offers artists all the tools and methods they need to create great, high-quality photographic work. Film also provides photographers the tools to resolve more detail than all but the most advanced, high resolution digital cameras. So, for the moment, film still lingers on as a valid, rich medium for photography.

与使用数码相机拍摄和从Photoshop进行打印相比，电影摄影师可能具有复杂而富挑战性的方法。但是，有些艺术家可能永远不会放弃电影，或者也许永远不会放弃数字作品。电影面临着诸多挑战，仍然为艺术家提供了创作出色，高质量摄影作品所需的所有工具和方法。除了最先进的高分辨率数码相机外，胶卷还为摄影师提供了解决更多细节的工具。因此，目前，胶卷仍然是一种有效的，丰富的摄影媒介。

Image Credits: Film Camera by e20ci, available under Creative Commons. New DSLR by Marcel030NL, available under Creative Commons. Film Cans By Rubin 110, available under Creative Commons. Kodak Kodachrome 64 by Whiskeygonebad, available under Creative Commons. Bathroom Darkroom By Jukka Vuokko, available under Creative Commons. Darkroom BW by JanneM, available under Creative Commons. DIY Darkroom By Matt Kowal, available under Creative Commons. Contact Sheet One by GIRLintheCAFE, available under Creative Commons. Darkroom Prints By Jim O’Connell, available under Creative Commons.

图片来源： e20ci的胶卷相机，可在“ 创用CC”下找到。 Marcel030NL的新DSLR，可在Creative Commons下获得。 鲁宾110的电影罐，可在创用CC下获得。 Whiskeygonebad的 Kodak Kodachrome 64，可在Creative Commons下获得。 Jukka Vuokko的浴室暗房，可在知识共享中使用。 JanneM的 Darkroom BW，可在Creative Commons下获得。 Matt Kowal的 DIY Darkroom，可在“ 创用CC”下找到。 GIRLintheCAFE的联系表第一页，位于创用CC下。 Jim O'Connell 创作的《暗房照片》(Darkroom Prints)，由Creative Commons提供。