|Posted: 2013-March-27 at 3:57pm | IP Logged
Hey Pogona, in response to your question about the lighting, there are a few things you can do to help with establishing distance.
This all depends on where your light source is.
From what I can tell for your specific picture; you can make the side of the left nebula which is facing the viewer a darker shade.
Make sure the edge of the left nebula, where it contacts (overlaps) the pixels of the nebula to the right, has a significant contrast to the light level of the nebula to the right (the nebula to the right having a lighter tone than the left nebula). This will help create the desired look of the nebula to the right being further behind the left nebula.
As for the top nebula, you can take a look at Earth : )
When looking at a mountain, as the distance between the viewer and the mountain increases; so does the volume of atmosphere between the viewer and the mountain. This filters out the color of the mountain with that of the atmosphere.
For your picture, I would try painting a layer or two of your primary background color covering the top nebula. Mess with the layer blend modes a bit, or just lower the opacity to make it look further back. I would suggest trying both out to see which you like the best.
Finally, you can look to composition; dominating horizontal lines create a feeling of vastness/large scale. You could try and rework your composition to include this feature if you choose. I, however, feel that this isn't the purpose of your picture as I see it in its current stage. Viewing it makes me feel more up close and personal to the content of the clouds, not their scale or vastness.
Hope this helps : )