A Beginner’s Guide to 3D Photography – Part 3: Stereographs

The concept behind a stereograph is not complex, it is simply a matter of creating two images to represent left and right eye viewpoints (as described in part 2), placing them adjacent to one another and then viewing them up close, preferably with a dedicated viewing device, so that each eye sees only one image; the left eye sees only the left image, the right eye only the right. Thus the illusion of binocular vision is created.

However, to make an effective stereograph requires a degree of precision. You will need to crop your images to a square, and then display/print them at a specific size, dictated primarily by your chosen viewer, or ‘stereoscope’. To develop this tutorial I have worked with the ‘Loreo Lite’, card viewer. This is a cheap and cheerful stereoscope which has the advantage of working well with stereographs printed to a standard 7x5in. It also folds flat and can be sent in the post along with a set of your prints to impress your friends and relatives in the far flung corners of the world. If you are using a different device, you will of course need to adjust your dimensions accordingly.

To begin, find your two images and establish which is the left image and which is the right, using the file numbers. Rename the left image ‘left’, and the right image ‘right’. Then open these images in Photoshop.

Next, go to…

File > Scripts > Load Files into Stack…

Choose ‘Add Open Files’

NB: Do not check the ‘Attempt to Automatically Align Source Images’ box! If you do, your stereograph will probably not work.

This will create a new file consisting of your two original images as layers within the same file. You should also see that the the layers are conveniently named ‘left’ and ‘right’

The next stage is to crop to a square format. The best way to achieve this is to perform a ‘targeted crop’.*

Select the crop tool and set the crop to 3.5in x 3.5in at 300ppi. Drag out you crop marquee to select you chosen image area, and press ‘return’.

Go to…

Image > Canvas Size…

‘Anchor’ to the centre left, then double the width of the canvas, in this example that would be 7in.

Select the ‘Move’ tool, by pressing ‘v’ on the keyboard, then target the ‘right’ image layer in the layers panel…

… then ‘shift-drag’ the right image to the right until it fills the newly created space, along side the left.

Save your stereograph and print out.

If you are using a desktop printer, make sure that you set the scaling in the print dialogue box to ‘100%’, not ‘Scale to fit media”.

>If you are sending your file out to be printed by a lab, order a 7x5in print, ensuring that the lab will not crop to fit the paper size, but will print to whole image with white space, sometimes referred to as ‘shrink to fit’. If you are unsure, it might be safer to create an image file which is 7x5in exactly.

Go to….

Image > Canvas Size…

Set the height to 5in.

Save as a jpeg file.

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