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Posted by: markril Sep 6 2012, 12:17 AM

Given the recent http://www.unmannedspaceflight.com/index.php?showtopic=7450 on 3D viewing, I wanted to share a few tips on cross-eyed viewing of stereo pairs. Below you will find two stereo pairs that have been prepared with a black frame. This frame makes it easier for your eyes to align the two images. Also, I outline two methods to assist in viewing the images, one that uses your hands only, the other requiring a couple of household items to prepare.


METHOD #1 (Hands only)

1. Open the image in the center of the screen. Don't magnify the image as it will be harder to work with when magnified. Be sure to move your mouse pointer to the edge of the screen since it causes unwanted interference. If you wear glasses to view your display, be sure to where them here.

2. Situate yourself roughly 2 feet (60 cm) in front of your display with your head centered between the pair of images and eyes vertically level with the center.

3. In the next steps you will hold your hands (palms facing you) about 4 inches (10 cm) in front of your face. Seperate your hands to either side so they are not blocking the monitor. You will be moving your hands in from the sides towards the center (one hand at a time) so that it will block one of the pair of images while maintaining the distance (4 inches (10 cm)) from your face.

4a. Close LEFT eye (leave RIGHT eye open).
4b. Slide in RIGHT hand until it blocks RIGHT side image.
4c. Hold this hand as steady as possible.

5a. Close RIGHT eye and open LEFT eye.
5b. Slide in LEFT hand until it blocks LEFT side image.
5c. Hold this hand as steady as possible.

6. Open both eyes and (hopefully) your eyes will fuse the two images into a single 3D view. If not, try moving your hands (together as a unit) forward or backward, left or right a little to help frame things while your eye is trying to fuse the image. If still not , try again from the beginning.

You may need to play with the various distances to improve your results. After a while you can just leave both eyes open and simultaneuosly bring both hands in from the sides to fuse the image in less than a second.


The images:

and:




METHOD #2 (Some construction required)

This cardboard frame serves the same purpose as your hands in the previous method. The advantage is that you only need one hand to hold it.

You will need an empty cereal box (or other thin cardboard) and a couple of paper clips:



Each half is roughly 5 x 7.5 inches (13 x 19 cm). Assembled it looks like this:



The trick is to adjust the width of the frame to the same width as your hands during the previous method. This distance will be about 1.5 cm (or so) less than your eye interpupillary distance. You can take the measurement from a pair of properly adjusted binoculars and then subtract 1.5 cm. Or, you can just start with 2 inches (5 cm) and work your way from there.

To use the frame, hold it centered and directly in front of your face - less than one inch (2 cm) away. You'll know it's centered when the frame blocks roughly half the vision of each eye.

Now, move the frame slowly away from you (keeping it centered) and at around 4 inches (10 cm) your eyes will (hopefully, again ) fuse the image. If needed, move the frame a little left or right, forward or back to help nudge your eyes into bringing the images together.


Anyway, I found these methods useful when starting to view stereo pairs. Maybe they'll work for you? Please let me know if I can clarify the description further and feel welcome to contribute any tips you may have to this thread.

Mark

Posted by: markril Sep 7 2012, 02:58 PM

Here's another one to play with, this one animated:

Mark

Posted by: Tom Ames Sep 7 2012, 11:33 PM

Fantastic! I really appreciate the opportunity to look at the stereo views without having to don the silly glasses. Especially at work. Please, keep it up!