Tutorial: Making VR180 Photos
In a
previous tutorial, I demonstrated how to convert photos from an ordinary camera into stereoscopic photos that could be viewed in a special viewer or in a VR headset. Today I will be demonstrating an alternative method which produces 180 degree stereoscopic photos from a standard 360 camera (I personally use an LG360 camera, but Ricoh makes a very nice one as well). It isn't difficult, but there are a few details that many people overlook in the processing steps.
As with the previous tutorial, the first step is to take the photos. You can either set the camera to take 180 degree photos, or you can use 360 degree photo mode and crop the photos later. You will need to take two photos in a short time without moving too much, and there are two options here. The handheld option requires you to hold the camera close to your right eye and take a photo, and then without moving your head, move the camera to your left eye and take the same photo again. Try to keep the camera pointed in the same direction each time, but we will be correcting this later in post-processing so it isn't too critical.
Alternatively you can mount the camera on a tripod and take the photos remotely. The only difficulty I have found with this method is that it is much harder to move the camera a few centimeters between the left and right shots, but it can be done. (As an aside, I recently purchased a device in my local photography shop that works really well for this. I am not sure what its proper name is, but it is a metal plate that attaches to the camera, and a metal track that attaches to the tripod legs. When the two plates are connected, they form a special tripod head that can only move in one direction, so the camera remains pointing in the same direction and at the same height while being free to move from left to right)
Next we need to process the photos, and this is where the process requires a few extra steps.
Load both of the images into your favourite image editing software, ideally as two layers on the same image, but remember which is the right and which is the left. Find an object in the photo that is very far away - distant trees and mountains work well for this. Set the opacity of the top layer to about 50%, and then move the top layer around until that distant object is aligned in both photos. You will never get everything in the photo aligned, or it wouldn't be a stereoscopic image, but human eyes should be parallel only when focused on an object at infinity, and so the most distant object in the photos should be in the same location to create proper alignment.
Now change the opacity back to 100%, and we can begin cropping. This method will only produce a good stereoscopic image for the center of each image, so we need to crop the sides. For a 180 degree image, create a selection square with an aspect ratio of one. The height and the width need to be identical to create a good image. Furthermore, never crop the photo in the vertical direction - the VR software that is used to view such images assumes that the image stretches from the ground beneath your feet to the highest point in the sky above your head, and if you crop the image vertically then when you view it everything gets stretched to match this requirement. If you do have to remove something from the bottom or top of the image, paint it out instead.
Crop both the left and right image using this selection. Copy and paste each cropped image to a new image that has the same dimensions as your original, unaltered photos, making certain to place the right image on the right and the left image on the left. Now save your image and you can use it in any VR headset!
My first attempt at using this method, and the realization that I have fat fingers and a big nose :)
As an aside, it is also possible to make 360 degree stereoscopic photos with this method, either by making 180 degree photos for the front and back (and maybe the sides as well), but they usually do not align very well at the edges. Once I have refined my method for dealing with this overlap I will post another tutorial here.
So that is the basic method of generating stereoscopic images with a 360 camera. It is the same method used by expensive, high end VR cameras but with a lot less cost and a lot more control over the final images. So go out and lets see what great images you can create!