Vol. 28: "Level Best" 3D Camera Slide-Bar Hack

You can make a DIY camera slide bar fast and cheap that’ll work just as well as a professional one.

By Bob Knetzger

Illustrations by Bob Knetzger



+ Downloads & Extras:

+ Here’s a quick tip on how to make your own red/green anaglyph stereoscopic prints.

1. Use the “Level Best” slide bar to take left- and right-eye views with your digital camera.

2. Open both images in Photoshop or your favorite graphics program.

3. Set the IMAGE> MODE> RGB COLOR for both images.

4. Open the “Channels” palette of the LEFT image. Click on the RED channel to select it (the other channels turn invisible and the screen image appears as black and white). SELECT > ALL and command-C to duplicate the red channel only info into scratch memory.

5. Open the channels palette of the RIGHT image. Click on the RED channel layer. SELECT > ALL and DELETE, then command-V paste into the RED channel. You have replaced the right image’s red channel info with that of the LEFT image. Click on the RGB channel to turn all channels visible. You should see a full color but double image, like a 3d comic book.

6. Print out and view with 3D re/green glasses. The glasses’ RED filter should go over your LEFT eye. Give your eyes a little time to adjust and just gaze at the image. If the 3D effect seems odd, flip your glasses over (maybe you swapped left and right views).

Depending on your camera, photo exposures and subject matter, printer and paper you may want to tweak the contrast before printing. If the images are too dark you’ll get “ghosting” when you view thru the glasses—that means each eye sees some of both images, ruining the effect. Try lightening up the image using LEVELS. Brightly colored red or green subjects in your photos also “pop” in odd ways when viewed with the colored glasses. You could also try desaturating the two images first, then reassembling them into a third RGB color space composite image to recreate a red/green anaglyph of a black and white 3D image.

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