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Cameras and Lighting 
 POV-Ray Tips, 
 Tricks, and Techniques
Orthographic Cameras? 
 
Christopher Templin inquires: Has anyone had any luck using the orthographic keyword in POV-Ray?  It either zooms in too closely or (when my negative translation of the camera reaches 10+ digits) shows nothing but background. Altering the direction value seems to have no effect.
Andreas Dilger applies his expertise:
 There are two ways to use the ortho camera: 

1) If you put the orthographic keyword first, then you need to scale the right and up vectors to change the size of the rendeed image. 

2) If you put the orthographic keyword last (ie after look_at and direction), then POV-Ray will scale the right and up vectors to match the approximate size of the rendered image that you would get when you had a perspective camera (ie the object at the "look_at" point will be the same size as with a perspective camera).  Objects closer than this will be smaller than with the perspective camera, and objects farther away will be larger, among other things. 

You have to realize that the ortho camera is very different that the perspective camera, as a unit-sized object 10 units away will be the same size as a unit-sized object 10,000,000 units away.  This may be what you want, and it may not.
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