Whilst the principle behind the anaglyph is perhaps more complex and challenging than that of the stereograph, the procedure required to make one is much quicker and surprisingly simple. Before we get to that stage however, we need to obtain some special 3D anaglyph glasses, or better still, make some.I have prepared a printable PDF template, available here. Simply download and print out onto thin card (or thick paper). You will of course need to supply your own coloured gels for the lenses. Ideally you should use pure red and pure cyan photo quality filter gels, such as those made by Lee Filters, but you can get away with similarly coloured cellophane from a craft store. In fact even sweet wrappers might do the job in an emergency*.
Cut out the template, assemble the glasses and affix the ‘lenses’ to the eye apertures. Make sure that the red is fitted to the left eye and the cyan is fitted to the right. If not, the effect will not work.
Before we make the anaglyph, I feel I should first explain the principle. As discussed in part 1, the anaglyph achieves its effect by recreating an impression of binocular vision. It does this by use of filtration, in this case selective colour filtration, allowing each eye to see only its corresponding image. The two source images are combined through software into a composite which appears to the naked eye as exhibiting pronounced colour fringing. In fact what has happened is that the left hand image is presented as the red content, or more specifically the red ‘channel’ of an RGB image, the right hand image exists within the blue and green channels, collectively displaying as cyan. The red lens placed over the left eye filters out the cyan content and thus the left eye only sees the red content, specifically the left-hand image. Similarly the right eye views only the blue/green channels as the cyan lens filters out the red content, and so the right eye sees only the right-hand image. Following so far? It might become clearer when you actually do it.
Open your two images and identify which is the left and which is the right hand image. If you are unsure, use the file numbers to help you.
Desaturate both images (optional, but often results in a more pronounced 3D effect).
Image > Adjustments > Desaturate
…or use the keystroke ‘cmd’ (OSX) or ‘ctl’ (Windows) + ‘shift’ + ‘U’
This will create a monochrome image but as an RGB file. Do not convert to greyscale!
Go to your right hand image and select it…
Select > All (cmd/ctl + A)
Copy to the clipboard…
Edit > Copy (cmd/ctl + C)
Now go to your left hand image.
Go to the Channels panel.
Click on the green channel, then ‘shift-click’ on the blue channel. (At this point your image will probably look to be blue/green, or ‘cyan’.)
Edit > Paste (cmd/ctl + V)
This will paste your right hand image into the blue and green channels of your left hand image.
In the Channels panel, click on the composite ‘RGB’ to switch on all channels. You should now be presented with a monochrome picture with significant red and cyan colour fringes.
Select > Deselect ( cmd/ctl + D)
Press ‘tab’ to hide the panels, then ‘f’ to enter full screen mode. Zoom your image to fill the screen, put on your 3D glasses and sit back to admire your work.
Don’t forget to save your anaglyph, as a new jpeg file (i.e. ‘File > Save as…)
*I have tested this theory using ‘Quality Street ‘ wrappers. I recommend a ‘Strawberry Delight’ for the left eye, a ‘Coconut Eclair’ for the right (try doubling up to strengthen each filter); works fine…