Making
3D Pictures
by
The
Red / Green Method
(Anaglyph)
Continued
Clive R. Haynes FRPS
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Tweaks and adjustments NB. To make 'global' changes to the image, change from the Channels palette to the Layers palette, otherwise you may find that you are adjusting one colour channel only! Sharpening: Use 'unsharp mask' at an appropriate level. Brightness: As viewing via red/green spectacles can darken the scene, extra brightness is often required. This is best done via an 'Adjustment Layer' (Layers > New > Adjustment Layer > Brightness & Contrast). 'Levels' or 'Curves' may suite you better, it depends upon what you need to do to the scene. Anyway, 'Adjustment Layers' are preferred for the task as they can be altered later without detriment to the image. Take care if you choose to erase parts of the Adjustment Layer mask by painting with black as it will be painting in two areas simultaneously! For more information about Adjustment Layers click on the link at the base of this page. |
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Re-alignment: The image (Red channel in this case) can also be rotated if required - do this via Edit > Transform > Rotate. However, remember to Select > All (Ctrl + A) first. |
| Wide angle and telephoto
considerations: If the original images are photographed using wide angle lenses then the depth will be exaggerated, sometimes unacceptably so. A shift of less than 3 inches may be preferred. Conversely, long focal length lenses usually need a wider separation to give an illusion of depth - in this case a separation of several feet may be required between left and right pictures. However, with greater separation it's more difficult to maintain correct registration. |
| Why desaturate?
The 3D picture can be perfectly well made without desaturation as outlined above, indeed in some cases better final contrast may result. However I have found that a more even image results if the three tonal ranges are the same to begin with. When starting with a colour original you may prefer to use only one of the channels available if that particular channel gives an improved monochrome rendering of the scene. |
| Improving the monochrome
image Improvements to tonality and contrast can be made by using 'Channel Mixer' (Image > Adjust > Channel Mixer, or accessible as an Adjustment Layer). Tick the 'Monochrome' box and alter the positions of the R, G, and B slider controls to suit). |
| What sort of pictures
work best? In my experience the scenes that work best have many 'planes' of image information, are of a gentle contrast range and avoid large, dark, featureless areas. Dark areas frequently reveal ghost images from the other channel which can be a distraction. |
| A great deal of experimentation is required to perfect the technique, however I hope that these notes will tempt you to have a go. |
| Where to get the spectacles .... Cardboard framed red / green 3D spectacles are inexpensive and may be obtained from The Widescreen Centre of London and Nottingham. Tel. 020 7935 2580 / 0115 945 5459 or go to www.widescreen-centre.co.uk/webshop they also supply the stereo pair slide viewer too. |
| No spectacles? - A quick alternative ....... If you have red and green filters for B&W photography, try them (red - left, green - right). |
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