rodeo_joe1 Posted April 20, 2020 Share Posted April 20, 2020 (edited) With lockdown giving me time to sit and think (always dangerous), I thought about applying oversampling noise-reduction techniques to film grain. As a proof-of-concept, I shot a series of identical frames of a still life. The frames, or part thereof, were then 'scanned' with a 24 Mpx digital camera to an equivalent resolution of about 7200 ppi. Here's the full frame, so that you can judge how small the cropped sample area is. This first crop is from a single frame showing the native grain - film is T-max 100 rated 80 EI and developed in HC-110. The grain is already pretty fine. Now a combination of two identical, but separate frames. To my eye there's a subtle improvement in the fineness of grain; about the root 2 improvement that theory predicts. Combining 4 frames would theoretically halve the grain, but what effect that would have visually I've yet to see. The scanned frames were combined using PhotoShop layers, carefully aligned and using the 'Darken' blend mode. I combined them as negative images before inverting them to a positive and adjusting the tone curve. Maybe combining them after inversion would give a different - worse? - better? - result. Who knows. It'll obviously only work with subjects that stand still long enough to shoot multiple frames that can be registered accurately. So. Daft idea or worth pursuing? You decide. I don't know how the below image got inserted, and seemingly I can't edit it out. Sorry! Edited April 20, 2020 by rodeo_joe|1 2 Link to comment Share on other sites More sharing options...
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