Combining or ‘stacking’ a group of similar images is a common photography technique. Which is why this article is all about learning how to use focus stacking in macro photography.
它经常用来减少噪音（例如Astrophotography.). Or to remove unwanted distractions, simulate long exposures or produce various special effects.
在ayx大小，它产生急剧聚焦的图像。从前到后面的对象的整个深度都是焦点。
什么是景深，与图像堆叠有什么关系
现代的DSLRS不要关闭镜头apertureuntil the moment you take the photo. But you don’t see the effect a lower aperture has on景深while composing a shot.
为了预览效果，如果它有一个，请使用相机的景深预览按钮。更多的场景焦点较小的孔。特别是如果您将相机切换到实时视图，而不会曝光仿真。
If your camera lacks a depth of field preview button, take a test shot.
同样的调整也将改变宏观摄影中的景深。ayx大小但它不会是您可能期望的金额。
您可能有足够的景深，为距离几米之遥等普通科目。但是，当您将相机更贴近主题时，这将下降。
这提出了宏观摄影的特殊困难。ayx大小在传感器上获得大型物体的大型图像意味着使相机非常接近主题。
您可以使用小孔径来最大化字段的深度。但将其关闭到最小值。将引入衍射。它会软化所产生的图像。
It’s quite common for the resulting macro depth of field to be only a few millimeters. Even when using a small aperture.
For the sharpest results, set your lens aperture to around the middle of its range. This is the sweet spot.
你将避免衍射柔软性。和一个浅景深在最大孔径拍摄时。
Even with the optimal aperture, the depth of field can still be small. Canon’s MP-E 65mm macro lens is capable of x1 to x5 magnifications. But it has a depth of field at full magnification of 40 microns.
There’s only so far you can go with camera and lens adjustments. Instead, you need a more sophisticated approach – and that is what image stacking provides.
How to Use Image Stacking to Get Around the DoF Limitations
要绕过DOF限制，请参加同一主题的几张照片。改变每次曝光的焦点，以捕获一系列急剧聚焦的“切片”。
这些范围从最接近的所选主题的最远点。
一旦您有一系列图像，您可以将聚焦区域与每张照片组合起来。这个'堆栈'将产生一个锐利的图像，其中整个主题是从前到后面的尖锐焦点。
这是理论。在实践中，还有更多的涉及混合一系列图像。
例如，采用印刷电路板的这种宏观照片。将这张照片正方形拍摄到电路板上可能更容易。
这意味着大多数部件将与相机和同时焦点相似的距离。但是，您可以通过靠近电路板的一个边缘的低角度拍摄更有趣的结果。
The problem is that even at f/16, the depth of field is too shallow.
The foreground is sharp. But the more distant components at the top of the frame are out-of-focus.
We need a series of images that sweep the focus into the image.
程序很简单：
- Set the camera to手动对焦和手动曝光。使用小孔径 - 尝试镜头的甜点。
- 专注于前景，如上所示，并采取第一次曝光。然后检查相机背面的结果。注意最锋利的区域是。将镜头重新聚焦到这一点以与前一个旧景深重叠。
- 休息并重复，直到你达到最远的程度。您需要的照片数将取决于字段深度。在这个例子中，我已经覆盖了四个图像的区域。
Take a look at these four images. You’ll notice it’s not only the focus that changes from one image to the next.
相机和主题保持在位置。但是从一张照片到下一个照片的每个组件的大小和位置发生了变化。
这是爸爸rticularly obvious in the background and foreground.
当您更改焦点时，您也会通过少量影响传感器上的图像的大小。
This is not something you’d notice with the naked eye. In theworld of macro photography，尝试混合图像时可能是一个重要的问题。
Blending the Image Sequence
在this example, blending is a two-stage process. We first have to deal with the variation in image size and position. After that we can select the areas of max sharpness from each image.
您可以将图像混合在Photoshop或使用专用软件中。
Let’s look at how to do this in Photoshop and then examine a dedicated focus stacking application.
使用Photoshop和Lightroom焦点堆叠
If you’re working inLightroom.，从库视图中选择要堆栈的所有图像。右键单击右键，然后选择“编辑”|'在photoshop中作为图层打开'。
不要混淆摄影学期在Lightroom中“堆叠”，并在这里尝试做什么。
Lightroom的术语仅指它在库视图中群体拍摄的方式，并且与图层无关。
If you’re working in Photoshop, go to Files | Scripts | Load Files into Stack.
如果您已将您的图像序列保存到文件夹中，则可以选择文件夹。或者您可以浏览个人照片。
确保勾选框“尝试自动对齐源图像”。这将适用于每个照片的有效大小的变化。
You’ll lose some of the image around the edges. But if you don’t do this, Photoshop will attempt to blend the various layers as they are.
这将产生像这样的可怕形象。
Image Alignment
You should see your photos arranged in the layers palette ready for processing. You might have already opted to align the layers during import.
You’ll see that Photoshop has reduced the sizes of some of the layers. These now have transparent borders. This size change facilitates alignment.
What if you’ve imported your images from Lightroom? You’ll need to instruct Photoshop to align them now.
To do this, click the bottom layer and then shift-click the top layer to select them all.
Then from the top menu, select Edit | Auto-Align Layers… Select the ‘Auto’ option and hit ‘OK’.
图像混合
Photoshop现在需要分析每个图像中的高空间频率。它需要掩盖低频空间频率。
这比听起来更简单。选择所有图层，然后从主菜单中选择编辑|自动混合层......
Select ‘Stack Images’ and tick both the other boxes and hit ‘OK’. After a few seconds, Photoshop will generate layer masks. These will reveal the sharp areas of each layer.
Photoshop将将这些图层与新合并的图层组合。这将出现在层面的顶部调色板。
You will then need to trim the resulting image to remove some blurred edges.
你应该最终完整的东西尖锐深度主题。
焦点堆叠使用Helicon焦点
如果您没有photoshop，还有其他选项。这些不仅对齐和混合焦点堆叠图像，而且还将自动化大部分过程。
最着名的是赫里昂焦点。它实际上是两个软件应用程序 - Helicon Focus和Helicon Remote。
Helicon遥控器通过电缆控制相机。这是为了将镜头缩小，拍照并将每个聚焦切片传输到计算机。
Helicon Focus堆叠一系列图像。它使得产生复合结果所需的所有调整。
这是这个过程的快速轮廓。将相机设置为手动模式(so the software can control it) and connect it to your computer.
Helicon Remote应该识别它并将相机切换到实时视图。这样你就可以看到电脑屏幕上的主题。
接下来，使用对焦部分中的控件（以上面的红色勾勒）将镜头聚焦在最接近的点。单击“A”按钮保存设置。
Then use the focus controls to move the focus to the farthest point you want to be in focus and click the ‘B’ button.
Helicon Remote can calculate how many photos you need and at what focus settings. It does this based on the exposure settings you set in the section above.
在这个阶段，你可以尝试不同的实验角度andlighting。您只是设置焦点调整范围。
我选择在合成器上包含键盘，以获得更苛刻的测试。我也使用了标准50mm镜头对于这个镜头而不是一个macro lens。这是为了表明，焦点堆叠不限于宏观摄影。ayx大小
一旦你满意的composition，您可以将工作交给Helicon Remote。
Click the ‘Start Shooting’ button at the top of the screen. Helicon Remote will then set the focus. And it will fire the shutter for as many photos as needed.
It will transfer each photo to the computer as it takes them so you don’t even need amemory card。一旦它拍摄了整个序列，它将可以选择在Helicon焦点中打开这些图像。
You are then presented with a list of component thumbnail images. There are also some options that control how blending will happen.
Clicking the Render button will start the chosen blend algorithm. This will take a minute or so to complete. You can watch it selecting the sharp areas of each component image in turn.
这是结果：
结论
Focus stacking is particularly useful in macro photography. But it’s also a great tool for achieving sharp images with任何镜头。
不要将自己限制在宏观镜片 - 尝试两者wide-angleand长焦镜头。
尝试使用该技术爱游戏ayx官方 , or产品摄影。Any situation where you can sweep the focus in a series of images is good to practise.
