One of the more exciting yet arduous post-processing feats of my Paris trip was creating this “planet panorama,” as I call it, at La Défense:
Creating an image like this is a work intensive process — it took me 6 hours. Here’s how to do it:
First of all, you need to shoot a >360° panorama. You’ll want to keep your camera completely level as you pan around. Many tripods have built in levels, and you can also buy one relatively cheaply that will fit into your camera’s hotflash mount. If you have a Canon 5D Mk III like I do, you can access a built-in level by going into live view and hitting the info button 3 times. The line will light green when you are level. Pretty cool, huh?
Be sure to overlap at least 15% between each shot, make sure you have some overlap beyond the point where you start. I guesstimate the overlap by picking a landmark on the righthand side of my image and making sure I include that landmark while I pan clockwise. The iPhone takes terrific panoramas, but you’re going to have a hard time keeping it completely level, plus the iPhone will not allow a 360° panorama, so you will still have to overlap multiple shots. Make sure you include ground and sky in all of your shots.
Once you’ve imported your images into Lightroom, select them and under the “Edit” option select “Stitch to panorama in Photoshop.” When the panorama window pops up, select “Auto” and check the box that says “Geometric correction.” Photoshop will then do it’s thing, cutting, pasting and merging, and this can take quite some time, depending on the number of images and the memory and processing power of your computer. Each pass took me between 15 and 40 minutes, and I’ve got a pretty robust MacBook Pro. You can sit there and watch if you like, but you might as well grab a sandwich or call your Mom or finish up that last episode of Game of Thrones.
Depending on your images, Photoshop may fail to stitch your images properly. This is a terrible bummer, and I hope the neighbors didn’t mind the loud stream of expletives that spewed forth after the long-anticipated wait. I don’t know why this happens sometimes, but if you examine the garbled image Photoshop produces, you might be able to tell which individual image(s) Photoshop had trouble with, and adjust your image selection accordingly when you make another attempt. I also recommend you shoot multiple panoramas and vary the focal length and degree of overlap. It took lots of trial and error with various images before Photoshop was able to stitch my images correctly. The fact that I used a fisheye lens may have compounded the problem.
If you’re lucky and you’ve been painstaking about panning consistently during your shoot, you should now have a completely straight image with some overlap on each side. If you’re not so lucky (like me), you’re image will be crooked. Fixing this can be a painstakingly difficult to impossible, but luckily Photoshop CC has an amazing tool called Perspective Warp which makes this operation a breeze.
The next step is to crop the image to a rectangle, and you want to slice the crop it at the edges of any redundant objects. In other words, if you have the same building at both sides of the image . You may notice some pixels missing around the edges, so you can either crop to exclude them or use the “content-aware fill” tool to let the computer try to fill in the blanks. Sometimes, it does an amazingly good job at this.
You then go into “Image Size”, uncheck the box that say “Constrain proportions,” and enter the same number in both the width and the height. A good approximation is 8000 pixels per side. Then rotate the image 180° and select the “Polar Coordinates” under “distortion,” and voilà! You’ll have to crop or otherwise touch up the corners, which will look weird, but other than that, you now have a planet panorama.
Now you can see why it took me all night to create this image. There are a few minor imperfections, but it’s close enough for government work. (Actually, since I don’t work for the government, I will probably go back and work on it some more.)