Easiest solution that comes to mind for me...

1. Go out and take a picture of the full mon on a good clear night.

2. Scan/download this to your computer, to act as a background image for reference.

3. Set up a hi-res sphere in Poser, with the moon image in the background.

4. Adjust  the camera settings until the sphere covers the whole moon.

5. Use an infintie light to light up the sphere. Animate it to start at directly behind the sphere, then move diagonally to light the lower right section of it, across the front of the sphere, and then off away round the top left, until you return to your starting point again. Make your last frame number 29. I recommend setting keyframes at each of the four 'quarters' (new, waxing half moon, full, waning half, and new again)., but you might want to add in midpoints as well at the crescent and gibbous pahases, too.

Make sure you keyframe 28, and then delete fram 29. This ensures that you have a steady looping set of frames.

7. Render out the animations as a series of tif files.

8. IN Photoshop/Gimp/graphcis program of choice, open you mon image, and your chosen frame from the lit sphere animation. Paste the lit sphere image onto the moon image, and use the 'darken' blend mode ( I think - it might be lighten, though). This will black out the area of the moon that is in shadow on the moon, and keep the lit section visible.

Since you have 28 images, you could do one image for each day of the lunar cycle ( I know that the cycle isn't exactly 28 days, but it's close enough). And since the moon always shows the same face to the Earth (it's period of revolution is the same as it's orbit), then you dont' have to worry about needing to change the background moon image.

I'm sure someone else wil come up with another solution, but this was just one that came off the top of my heda.

JonTheCelt