Make your own free website on Tripod.com

Cathedral Grove Kauri Trees

A large Anaglyph

By John Wattie

Start

Stereoscopic anaglyph  Music Control Here  
  If the music is distorted (more common with Quick Time than Windows Media Player), 
  stop it with the control and start again. (There are patches to cure Quick Time glitches when playing .avi files, and maybe Apple should fix how it plays midi files too).

 

 

 

 

A bigger view of the main trees of
 Cathedral Grove, 
Waipoua forest 
in Anaglyph format

(Red green/blue glasses) 

 

 

 

 

 

An interesting way to check the frame level while viewing an anaglyph is to put your mouse cursor on the picture and move it about. 

You will soon find most of this picture is behind the cursor, except for objects at the frame level.

Try this cursor trick on an object sticking out of the frame here, and it will go behind or through the air-craft wing!

(Close the new window to get back here or you will get multiple open windows)

 

Anaglyph format, like liquid crystal glasses, allows the biggest picture of all on a computer screen. 

This is a colour anaglyph and since there are no red flowers, the colour is fairly true, but not as good as the X and U versions needing eye gymnastics.

Stereo failure  

occurs where a close object obscures distant objects for one eye but not the other. Since these parts are not seen with two eyes, they cannot have a stereoscopic effect. In real life we move our heads to overcome that, but stereo failure in small parts of the picture is a defect of stereoscopic photography. You see it to the sides of the nearest kauri tree trunk. 

Holography may avoid this, but is beyond my technology.

In pictures showing obvious stereo failure, you also get double vision. This happens in real life too, so I do not need to apologise, it is just brought to your attention. 

Looking at a distant tree, it is seen in stereo but the near tree will be seen double, and vice-versa. Stereo is computed by the brain when there is a slight difference between the images seen by each eye. If there is a big difference, we adjust the eye convergence to correct it, as explained in the physiology section. The three dimensional impression is built up as we gaze around the picture, by repeated eye convergence changes and stereo analysis of individual areas.

Anaglyph windowing

Stereo windowing involves manipulating the distance into the picture occupied by the edge (or frame) of the picture. 

The stereo window is set by:

  1. deciding on an object which is at the desired window  level. 

  2. Arranging the object to be equidistant from the adjacent vertical margin on the two pictures. 

  • It is not necessary for the two vertical frame edges to be at the same level, and there are examples purposely set up on this web site where they are not. The result is a window which is vertical but sitting at an angle, running away from the viewer. 

  • The edges do not even need to be vertical, which makes the window frame tilt towards or away from the viewer. 

For a simple conventional anaglyph:

Set the two pictures in register at the desired stereoscopic frame level. 

  1. No matter how you crop after that (elliptical, random) the pictures will always have the frame at the registration level. 

  2. Most people will then see the frame as being the same distance away as the computer screen. 

  3. The real distance of the frame will hardly ever be the same as your computer. In this picture the frame is set on the front of the nearest tree trunk. This was about 5 meters away at the time of photography, much further than your monitor. 

  4. Since the window is much further away than you have been forced to imagine, everything in the frame looks far too small.

But, it gets worse!

  1. This is hyperstereoscopy: the cameras were about 1 meter apart.

  2.  Your eyes are only 6 to 7 cm apart. 

  3. You are seeing the trees with the head of a giant, and so they look small.

Here we have some of the biggest trees in the world looking small! 

That is the price we pay for an enhanced stereoscopic effect.

Not good. There is only one way to see the trees full size and in true three dimensions - come to New Zealand, walk amongst them and see for yourself. (In the meantime I will have to work out a stereoscopic virtual reality ... but I don't know how!)

Three stereoscopic versions of Cathedral grove are provided: 

  1. general view   (cross eye and parallel view stereo) 
  2. bigger picture (cross eye and parallel stereo)  The distant trees 
  3. Bigger still     (Anaglyph format)                    The near trees.

 

 links

 

 

 

Cathedral Grove, Waipoua Kauri Forest.

  

 

 

 

 

 3D contents page

Stereo Picture Gallery

Anaglyphs              

 Stereoscopic Kauri trees from Waipoua:   [Back Back to toadstool 1]

  This is a midi file Haydn, Timete Deum   

Escape from 3D:  New Zealand Images   

    Back to the home page          

start again

NZ Scenery Home Page