Photography Tips and Tricks
How and why to do photo stacking
Audiences: This blog is meant for every photography enthusiast with basic knowledge of Photoshop.
Keywords: Image stacking, f-stop stacking, focus stacking, time-lapse.
Stacking is about placing images -generally of the same subject or scene- on the top of each other to create: 1- an image with a deeper depth of field (f-stop stacking), 2- an overall in focus image (focus stacking), 3- to create distinct visual effects, 4- to create a time laps (photo or video).
The aim of this article is to show you how to stack images in photoshop to create distinct visual effects. In future blogs / videos, I will address other types of stacking.
To begin with, take a look at the featured image of this article.
There, you see a stream of people walking on the stairs that leads to Prague’s Castle in a cloudy day. While the image has a deep depth of field, the people are vaguely captured. I made the image in this way to emphasise on the temporary nature of our existence in places, people coming and going and the surrounding remains more or less the same. Having this in mind, it was not purposeful to capture people sharply, since it would place attention on the individuals at that specific moment on these stairs.
In order to create this image I would have several options. For instance I could make the shutter speed slow to capture people in motion blur, while the surrounding would remain sharp. That might have worked perfectly in such a cloudy (dark) day. Other option, which has been used here, was to make several images (unchanged camera setting / unchanged focus) and then stack them together in photoshop to create this image. So, let’s see how it works in practice.
How to create stacked images
At the time of shooting:
1- Be mindful that simple and motionless subjects will often work better for image stacking.
2- Use a tripod.
3- Focus manually (or focus using auto focus then switch to manual focusing).
4- Exposure setting (Aperture, shutter speed, ISO) according to your liking, but keep the ISO low when possible.
5- Use a cable release (or self timer) when the shutter speed is slow.
6- If you are handy with post processing then shoot in Raw, otherwise shoot in the highest quality JEPG your camera offer.
Initial Post processing;
Here I normally start with general global adjustments like lens and white balance corrections in Lightroom. Then I export images as JPEG to a dedicated folder.
Alternatively you can open your images directly into Camera Raw and perform the global adjustments there.
Photo stacking in Photoshop
Go to file < Scripts < Load files into stack
Then using “browse” navigate to the folder where you have saved your images.
If you have been shooting handheld, make sure “Attempt to Automatically Align Source Images” is selected.
Then press “Ok”.
It will take some time before photoshop opens all images into layers. If you do not see the layer’s panel, go to “Window < Layers”.
After photoshop is done with stacking, the image you see on the screen might not depict the visual effect you wished for. To bring that out, select all images on the layers panel. Go to Blending option (in de layer’s panel) and try a blending mode that works best for your intention. E.g. in the feature image of this blog, people are quite dark comparing to the surrounding, hence, a dark blending mode would work best. If the subject(s) were bright then a light blending mode would work best. But go through all blending options and pay attention how each blending mode creates a different mode / image.
It is always a good idea to check the result and see whether you need for instance to exclude one or more images from the stack (simply by clicking to the eye left to each image on the layer panel) or to use layer mask to bring back some original features you have missed in the stacking process.
Final post processing:
Once you are happy with the result of stacking, you can flatten all images to a single image, which makes the file much smaller in size. Thereafter, you can still edit this image like any other image you edit and export / or save it in the format of your choice.
Other examples of image stacking as described in this article.
If you have read my previous blog about light trails you have seen Image 2. This image is also made in the same way, which made it possible to show the fire work and also to increase the light trails on the streets.
Figure 1. In this image photo stacking is used to increase the light trails on the street and also to include the firework on the top left corner.
Other example would be to create a milky look on the surface of streaming water by image stacking when you are unable to create a slow shutter speed.
Now you can come up with your own stacked images / ideas. If you are happy with the result of your photo stacking, please do not hesitate to send me a copy so I would share it on our Facebook page.
I hope this was helpful. Should you have any question or remark please do not hesitate to send me a message.
Triangle Photo Academy team