To better integrate the scene, I created a fog effect using the Fractal Noise filter and a render Z-depth pass as a mask to give depth to the effect (Fig.21).
After adding the fog to the scene I used three more Adjustment Layer with the following filters: Brightness & Contrast, Levels, Shadow/Highlight and Hue/Saturation to correct and adjust the scene. Only after that did I add the layer with the snow (Fig.22).
With that I finished the After Effects stage of the render and took the image back into Photoshop. I felt that I still needed to make further adjustments, such as the frosted metal parts of the airplane, composing an Ambient Occlusion render pass, adjusting the background to give the scene a little more contrast and turning to tone to a lighter blue (Fig.23).
To continue to adjustment, the next stage was to select all the layers and convert them into Smart Objects to simulate the effect of a 35mm film. In order to do that I used the filter Lens Correction to create an effect of chromatic aberration, increased the sharpness of the image with the Sharpen filter and applied a grain with the Add Noise filter.
On the top I applied three more Adjustment Layer for fine adjustments and once again I converted all the layers into Smart Objects to continue to work on the 35mm film effect (Fig.24).
Now came the final stage, where once again I applied a series of filters intending to soften the edges of the image but also maintaining the sharpness and the correct level of grain.
A major "problem" of 3D is that it makes everything very perfect, smooth and clean. And when we work with film the scene ends up with imperfections such as softened edges, grain and some dirt due to dust and micro scratches. And as I used to say, in order to make it look good, we have to make it look "bad" (Fig.25)!
And here's the final image (Fig.26)!
I would like to thank all of my friends for their help and I hope that you all have enjoyed this "Making Of".