Adding A More Realistic Film Grain Effect

gmitchel850gmitchel850 Registered Users Posts: 100 Major grins
edited March 14, 2009 in Finishing School
I wrote a recent blog entry on simulating digital film grain. This action set builds on that discussion.

http://www.thelightsright.com/CreatingARealisticFilmGrainEffect

I just posted a Photoshop action set that implements some of the ideas from that blog entry.

http://www.thelightsright.com/TLRFilmGrainEffects

The film grain effects start with the basic Add Noise filter. This keeps the action set compatible with older versions of Photoshop. This is applied to a layer with an Overlay blend that's filled with 50% gray. You can intensify the film grain effect by changing the blend to Hard Light or reduce the effect with a Soft Light blend. You can also adjust the layer's opacity.

With an RGB photo, the Add Noise filter is applied separately to the Blue, Green, and Red channels (from bottom to top in the Layers stack). Different settings are used, with the Blue channel receiving the strongest grain effect and the Red channel the lightest. With a Grayscale photo, there is only one channel. The noise in this step has a Gaussian distribution.

The noise is then manipulated to make it clumpier. This is done by applying in turn a Gaussian Blur and the Median filter.

Another pass of Add Noise is applied. This one uses a Uniform distribution for a different pattern. This also helps ensure that there will be noise elements of differing size. This noise is sharpened with USM sharpening instead of being blurred. Sharpening the noise also helps to ensure there is some negative film grain.

The effect of the noise is "rolled off" from the deepest shadows and the brightest highlights. This is done with the layer's Blend If sliders.

This is the first version of the TLR Film Grain Effects action set. Comments about the technique and the results are welcome.

Cheers,

Mitch
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