Objects not visible from camera view

[Anonymous]

Hi, I'm a completely novice user so go easy! I'm trying to model a solar eclipse using Autocad. I have the three spheres of sun, moon and earth set up to the correct sizes and distances, all three aligned along the Y axis with their centre points at the same height. I've positioned a camera on the earth sphere in a central point with its target as the sun and perspective on. There's no clipping active on the camera. When I use this view in parallel mode I can see the moon centrally in the sun (but much much smaller of course). When I switch to perspective view, where the moon should cover the sun, the moon is nowhere to be seen. It just doesn't show at all in that view, despite it being right in front of the camera. I added a test camera 1 million units farther back from the earth - same thing happens, ie the earth is not visible in the camera perspective view, despite it being right there in front of the camera (but the sun sphere is visible in both views). The scale is obviously huge - 93 million units between sun and earth, but I just can't work out why the closer objects are not rendering in the camera view.

Thanks in advance for any help.

[dmfrazier]

Would you be willing to post a copy of the DWG?

Some images of what you describe would also be helpful.

[leeminardi]

Let's assume earth is at 0,0,0 world UCS. 

Moon is at 0,239000,0 dia 2158  color  yellow

Sun is at 0,93000000,0 dia 865370 color red

Place the moon n the moon layer and the sun on the sun layer. 

Place a camera at 0,0,0  and select the camera.  This yields:

The yellow sphere is the moon.

Freeze the moonl  layer and you get:

The red sun.

With the moon and the sun layers thawed but the camera target is changed to 93000000 you will not see the moon no matter what's its diameter!

[Anonymous]

Hi, thanks for the reply that’s useful. Can I ask why the camera won’t see the moon if its target is set as the sun? I assumed the camera view would replicate the view you would have if you were standing at that location pointing a camera in that direction, in which case the camera would see the moon blocking the sun. As I said, novice user so not sure why the camera would not see everything in its path. 

thanks