Can anyone help with tips on how to create a more realistic space scene.  Im just using spheres and stars - but I want more in there - coloured nebulae and cloudy heavenly expanses - hubble space telescope type of images.
Also Im wanting to do a poster for a friend - a misty forest scene - but cant figure out how to get a nice deep mist from ground up - with a good depth of field.
Ive googled for tuts but havent struck paydirt on these.
Hope Im not being a pain here - still a noob - but trying to learn all I can.

Im so sorry - half asleep and posted this in the wrong place.  I will try and move it.

If you like the Hubble images, you may well be able to use one or a mixture for your images for your background. NASA and STScI are pretty generous in regards to use of their images.

Here's their copyright notice and usage restrictions. NASA / STScI Copyright Notice

Fog...depends on what software you're rendering. A lot of them will have a "distance fog" and some will even have a "ground fog" option available.

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fogs and mist can be faked in poser by using a few plane primitives with a texture, either  images or procedural.  You should find some tutorials. Poser does do atmospherics, read the manual on it and volumetric lights.

Attached Link: http://www.apophysis.org/

Soem cool effects taht might work for you you can make in Apophysis. Link provided.

The wit of a misplaced ex-patriot.
I cheated on my metaphysics exam by looking into the soul of the person next to me.

These Photoshop tutorials can be enhanced with background elements from your 3D app - for example, asteroids or replace the 2D planet with a 3D one.

http://www.freephotoshop.ca/tutorials/effects/photoshop-space-and-planet-tutorial

http://www.smashingmagazine.com/2008/08/07/50-photoshop-tutorials-for-sky-and-space-effects/