pre 图像稳定

Image stabilization is a feature of some lenses and cameras that avoids the blur of a shaky camera. By counteracting that shake, you can use a slower shutter speed than you normally would, without getting a blurry photo. This is especially useful for night photos, or other situations where slow shutter speed is a necessity.

图像稳定是某些镜头和相机的功能，可以避免抖动的相机模糊。 通过抵消这种抖动，您可以使用比通常更低的快门速度，而不会产生模糊的照片。 这对于夜间照片或其他需要降低快门速度的情况特别有用。

When we talk about image stabilization and photography, we’re normally talking about optical image stabilization, which is found in a lot of high end lenses (and some high-end smartphones like the iPhone 7). Canon calls the feature Image stabilization (IS) and Nikon calls it Vibration Reduction (VR). With optical image stabilization, part of the lens physically moves to counteract any camera movement when you take the picture; if your hands are shaking, an element inside the lens shakes too to counter the movement.

当我们谈论图像稳定和摄影时，我们通常是在谈论光学图像稳定，这在很多高端镜头(以及一些高端智能手机，如iPhone 7)中都可以找到。 佳能将其称为影像稳定(IS)功能，尼康将其称为减震(VR)功能。 借助光学防抖功能，在拍摄照片时，镜头的一部分会物理移动以抵消相机的任何移动； 如果您的手在晃动，镜头内的元件也会晃动以抵消其移动。

Other cameras, including some smartphones like the iPhone 6S, can have a feature called virtual image stabilization. With virtual image stabilization, the lens doesn’t physically move; instead, the movement is recorded and the camera tries to reverse any shake algorithmically. It’s not nearly as effective, but it’s better than nothing.

其他相机(包括某些智能手机，如iPhone 6S)可以具有称为虚拟图像稳定的功能。 借助虚拟防抖功能，镜头不会物理移动。 而是记录运动，然后相机尝试通过算法反转所有抖动。 它几乎没有效果，但是总比没有好。

Today, we’re going to talk a bit about how to use image stabilization effectively. For the purposes of this guide, we’re going to focus on the optical image stabilization found in high-end cameras.

今天，我们将讨论如何有效使用图像稳定功能。 出于本指南的目的，我们将重点介绍高端相机中的光学图像稳定功能。

互惠规则：您走多慢？ (The Reciprocal Rule: How Slow Can You Go?)

With a regular lens, the slowest shutter speed you can still have sharp pictures with is generally assumed to be the reciprocal of the focal length of the lens (or the full frame equivalent focal length if you’re using a crop sensor camera). This means that if you’re using a 100mm lens on a full frame camera like a Canon 5D MKIV, the slowest shutter speed you can get away with is 1/100th of a second. For a 50mm lens, it’d be 1/50th of a second.

使用普通镜头时，通常仍能获得清晰照片的最慢快门速度通常被认为是镜头焦距的倒数(如果使用裁剪传感器相机，则为全画幅等效焦距 )。 这意味着，如果您在佳能5D MKIV之类的全画幅相机上使用100mm镜头，则可以摆脱的最慢快门速度是1/100秒。 对于50mm镜头，则为1/50秒。

If you’re using that same 100mm lens on a camera with a crop factor of 1.6 like a Canon EOS Rebel T6, then it’s equivalent to a 160mm lens on a full frame camera, so the slowest shutter speed you can safely use is 1/160th of a second; the 50mm lens is equivalent to 80mm for a shutter speed of 1/80th of a second.

如果您在裁切因数为1.6的相机(如佳能EOS Rebel T6)上使用相同的100mm镜头，则相当于在全画幅相机上使用160mm镜头，因此您可以放心使用的最低快门速度为1 / 160秒； 对于1/80秒的快门速度，50mm镜头相当于80mm。

It’s important to note that the reciprocal rule only applies to camera movement. If you’re taking a photo of a fast moving object, you might need to use a shutter speed way faster than what the reciprocal rule says you can get away with.

重要的是要注意，倒数规则仅适用于相机移动。 如果要拍摄快速移动的物体，则可能需要使用比对等规则所能说的快的快门速度。

图像稳定如何降低快门速度 (How Image Stabilization Allows for a Slower Shutter Speed)

With image stabilization turned on, you can use a shutter speed between two and four stops slower than what you otherwise could. Let’s go back to our 100mm lens example. Instead of a minimum shutter speed of 1/100th of a second, image stabilization would allow you to use a shutter speed as slow as about 1/10th of a second and still have a sharp image (at least in ideal circumstances). For the 50mm lens, you’d be able to go as low as around 1/5th of a second.

带防抖开启时，您可以使用两个和四个之间的快门速度停止你所想的，否则可能较慢。 让我们回到我们的100mm镜头示例。 图像稳定功能可以使您使用低至约1/10秒的快门速度，而仍然具有清晰的图像(至少在理想情况下)，而不是1/100秒的最小快门速度。 对于50mm镜头，您可以低至约1/5秒。

In the image below, I shot the photos with a 200mm equivalent lens with a shutter speed of 1/40th of a second. In the one on the left, image stabilization is turned off; in the one on the right, it’s turned on. It’s easy to see how effective image stabilization can be in the right circumstances.

在下图中，我使用200mm等效镜头以1/40秒的快门速度拍摄了照片。 在左侧的图像中，图像稳定功能已关闭； 在右边的一个中，它已打开。 很容易看出在正确的情况下图像稳定效果如何。

If you’re shooting at night or in other low light situations, being able to get away with a slower shutter speed can make a big difference. You don’t need to crank your ISO so high, or use a really wide aperture, if you don’t want to.

如果您是在夜间或其他弱光条件下拍摄 ，则能够以较慢的快门速度逃脱可能会产生很大的影响。 您不需要将ISO调得很高，也可以使用非常大的光圈。

Image stabilization can also help with longer lenses even in good lighting. If you’re using a 300mm lens, the absolute slowest shutter speed you can get away without image stabilization is 1/300th of a second. This is still a pretty fast shutter speed if you’re using a narrow aperture and low ISO. With image stabilization, though, you could go to around 1/50th of a second if you needed, but you could also just go to a slightly slower shutter speed like 1/200th of a second. This lets in a little bit of extra light, but more importantly makes it more likely you’ll get sharp images. Just because you can go to a really slow shutter speed, doesn’t mean you should.

即使在良好的照明条件下，图像稳定也可以帮助使用更长的镜头。 如果您使用的是300mm镜头，则在没有图像稳定的情况下可以摆脱的绝对最慢快门速度是1/300秒。 如果您使用窄光圈和低ISO，这仍然是相当快的快门速度。 不过，有了图像稳定功能，如果需要，您可以达到约1/50秒，但是快门速度也可以稍慢一些，例如为1/200秒。 这样可以增加一点额外的光线，但更重要的是，它更有可能获得清晰的图像。 仅仅因为您可以降低快门速度，并不意味着您应该这样做。

Again, it’s important to note that image stabilization only helps with camera movement. It has no effect whatsoever on any movement of the subject. Even a person standing still for a portrait moves a little bit; if you use a shutter speed that’s too slow, their movement will show up in the image.

同样，重要的是要注意图像稳定只会帮助相机移动。 它对主体的任何运动都没有任何影响。 甚至一个人站着静止不动，也会移动一点。 如果您使用太慢的快门速度，它们的移动将显示在图像中。

影像稳定化的问题 (The Problems With Image Stabilization)

The biggest problem with image stabilization is the cost. Canon’s EF 70-200mm f/4L USM which doesn’t have image stabilization costs $599, while the EF 70-200mm f/4 L IS USM—which does—costs $1099. Other than one having stabilization, the two lenses are almost identical. The same pattern holds true with a lot of other lenses, with one version without stabilization that costs hundreds of dollars less than the version with stabilization.

图像稳定的最大问题是成本。 佳能的没有图像稳定功能的EF 70-200mm f / 4L USM售价为599美元，而拥有70-200mm f / 4L IS USM的售价为1099美元。 除了具有稳定功能的镜头以外，这两个镜头几乎相同。 许多其他镜头也具有相同的模式，一种不带稳定器的镜头比带稳定器的镜头要便宜数百美元。

If you can afford to pony up for image stabilization, it can be a great feature, but unless you’re sure it’s something you are going to use, the extra cost might not be worth it. If you shoot a lot with long lenses or in low light, it can be great, but if you don’t, it might be a waste of money.

如果您有能力提高图像稳定性，这可能是一个很棒的功能，但是除非您确定要使用它，否则额外的成本可能不值得。 如果您使用长镜头或在弱光条件下拍摄很多东西，那可能会很棒，但如果您不这样做，那可能会浪费金钱。

Image stabilization can also have some weird effects if you use it in the wrong situations. Once your shutter speed is above around 1/500th of a second, image stabilization won’t really improve your images. Your muscles don’t twitch 500 times a second! Instead, it can actually have a detrimental effect on the sharpness of the image because of the moving elements in the lens. Although it’s mainly anecdotal, most professional photographers turn image stabilization off unless they absolutely need it for this reason.

如果在错误的情况下使用图像稳定器，也会产生一些奇怪的效果。 一旦您的快门速度超过1/500秒左右，图像稳定将无法真正改善您的图像。 您的肌肉不会每秒抽动500次！ 取而代之的是，由于镜头中的移动元件，它实际上会对图像的清晰度产生不利影响。 尽管它主要是轶事，但大多数专业摄影师会关闭图像稳定功能，除非出于这个原因他们绝对需要它。

By the same token, if you’re stabilizing your lens in another way, like with a tripod, image stabilization should be turned off. At best, it will do nothing, and at worst it will actually make your photos blurrier.

同样，如果您以其他方式稳定镜头(例如使用三脚架)，则应关闭图像稳定功能。 充其量，它什么也不会做，而最糟糕的是，它实际上会使您的照片模糊。

Finally, image stabilization also uses a bit of power. If you’re trying to conserve battery life, turn it off.

最后，图像稳定还需要消耗一些电量。 如果您要节省电池寿命，请将其关闭。

Apart from those downsides, image stabilization really is is a great feature, and it’s becoming standard in more and more lenses. Just make sure it’s worth the extra cost.

除了这些缺点之外，图像稳定确实是一个很棒的功能，并且它在越来越多的镜头中已成为标准。 只要确保它值得额外的费用。

翻译自: https://www.howtogeek.com/298560/what-is-image-stabilization-and-how-does-it-work/

pre 图像稳定