There are plenty of folks out there shooting and displaying time-stack images and even a few folks writing and creating video tutorials about them. But yet, nothing I have seen describes what to look for in the cloud formations that are needed to help make a successful image! From my experience, this is one of the biggest factors in producing that successful time-stack image. In this article I will show you a few cloud formations and the time-stack images that I created as a result of those formations. I will also discuss a few other components that I take into consideration when composing my time-stack images along with revealing a few tips on how I end off the processing of them.
According to Wikipedia, composition is define as the placement or arrangement of visual elements or ingredients in a work of art. Visual elements? Why can’t I just include this rock over here, or that tree over there and those mountains way back there in my picture? Well, I can, those are the visual elements referred to in the definition! Even the clouds that I want to capture in the time-stack are visual elements. The clouds will be the main element that I want to build the rest of my composition around. I don’t know exactly what they are going to look like yet, but I certainly know where they will be in my composition.
As with almost any image I create I will scout out a location before actually doing a shoot there. In scouting out an area I will walk around and study the surrounding landscape. The first thing I determine is whether I am looking at a morning or an evening shoot, from there I will look for any visual elements that will enhance the overall composition. This may include, on the natural side, seashells, stones, rocks, trees, mountains, ice chunks, even snow covered mounds of earth. It may also include man made items such as walls, docks, lighthouses and the list goes on! In looking at these elements I have to decide how I want to use them in the composition. I’m not going to go much further with my thought process on the composition, it would be just to entailed for this article. What I will do though is recommend a fantastic book by fellow photographer Ian Plant. I consider his “Visual Flow, Mastering the Art of Composition” to be a must read for anyone looking to further develop their compositional skills.
After getting familiar with the area, I am now ready to give attention to the main visual element of the composition, the clouds!
In considering the clouds, I want to touch base with a little science first. I promise to keep it short! The physics of relative velocity dictates that any clouds near the horizon will show minimal movement over the time period needed to capture the time-stack images. At the same time, cloud formations closer to overhead will show substantial movement. Keeping this in mind, I’ll end with the science and state that I do not to use a long lens because the cloud movement just won’t be there to create a successful image. I use my 17-40mm wide angle for all of my time-stack images. In using this lens I will want a fair amount of clouds extending up into the sky above me. I don’t want a solid cloud base, but more of a scattered cloud coverage.
The best way to describe what I look for in the cloud coverage is to show you. In the following series of images the image on the left will be a single exposure that begins the series used for the time-stack. On the right is the resulting time-stack image.
OK, now that you have an idea of what to look for in the cloud cover you can keep an eye to the sky as sunrise or sunset nears and know if it’s got the potential before even heading out to your location. The sunrise examples shown here were shot in the 10 minute period leading up to sunrise, and the sunset images in the 10 minutes following sunset. In planning your shoot take this into consideration for your arrival on site and don’t forget to give yourself time to compose the shot and setup the camera!
Before running out the door to start shooting, here is a helpful tip in finalizing your composition. After setting my camera up for the final composition I will shoot off 3 or 4 images each about 5 seconds apart. I will then scroll through those images on my camera back just to get an idea of what the cloud movement will be like, the direction it is going and where it originates from within the composition.. From what I see in reviewing the images I may make one final composition adjustment that will place the visual element of the clouds in a location within the total composition that works with the other visual elements.
I’ve captured my images, loaded them into individual layers in Photoshop and changed the layer type to Lighten for all but the first image loaded. I have a beast of a file to work with now, everything will run slow. If I am happy with the cloud display in the time-stack I will Flatten the Image layers to make the file response bearable. Now I can post process my image with relative ease.
With all my post processing done I will perform two final steps to complete my images. I will pass them along here to you as tips.
Tip #1: In the process of changing my layer type in Photoshop from Normal to Lighten I will be allowing lighter portions of the underlying images to show through across the whole image. The reality is that I only want the effect to come through in the clouds. By allowing the effect to show through on my static visual elements, I run the risk of seeing double exposures or slight shifts in the elements if there was even the slightest bit of movement over the several minutes of exposures. I will go back to the original images and choose one that shows my static visual elements as I want them to be, crisp and in focus. I add this single exposure image as the very top layer in my time-stack file. Then I add a Layer Mask to this layer and paint over the sky to allow the time-stacked clouds to show through. This will give you a very clear and sharp rendition of the static visual elements in your scene, while at the same time displaying your time-stack clouds.
Tip#2: Smoothing out the clouds! Some folks like the jumpiness inherent in the clouds when stacking the images together. Others prefer to see them smoothed out. I will use the Motion Blur Filter to smooth the clouds out in my images. The Motion Blur Filter allows the effect to be applied in a single definable direction but yet the clouds are usually showing movement in many different directions. Because of this I will have to apply the filter to small areas of the image where the cloud direction and the motion blur angle setting match and then repeat the process until I have smooth out all areas of the clouds. It’s a tedious process but can really have great results. The following two images are the same, one has the Motion Blur Filter applied while the other doesn’t. It’s easy to see the difference.
To smooth the clouds I will duplicate the layer the clouds are on and then convert it to a Smart Object. I will apply the Motion Blur Filter to the smart object layer that was just created. I want to adjust both the Angle and Distance settings until I have smoothed out the clouds in a particular area of the image. After I make the adjustment to the filter I will add a vector mask to the background smart object layer. Note that there is already a mask layer available for the Smart Filters, I do not want to use this one. After using the fill bucket to paint the smart object layer mask black I switch to the paint brush, set my foreground color to white and then paint the mask only where I want the current Motion Blur Filter settings to display. Just as with any layer adjustments and masks I can come back later and adjust both the filter settings and mask. I then repeat this process working across the image until all the clouds are smoothed. It takes a little practice and patience but is well worth it.
So there you have it, what to look for in the clouds and the importance of paying attention to the composition as a whole. Now go make some dynamic time-stack images and when you come back don’t forget to incorporate those processing tips into your final image! Good Luck and have fun!