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Comment by shagie | Hacker News Reader

The "synthetic lighting" was the one that made me go o_O back in the day - http://graficaobscura.com/synth/index.html

The idea of modifying a digital image so that there is a negative shadow was rather mind-blowing to me at the time.

There's also the photographic stitching software c. 1994 which was cutting edge for its day.

Another related piece of it - http://www.employees.org/~drich/SGI/SiliconSurf/grafica/inde... which has a "future" (which I don't think ever came to be).

Another piece can be found at http://sgifiles.irixnet.org/sgi/graphics/grafica/

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That is awesome. So obvious when you think about it, I wonder what practical applications it has. Do photographers know about this?

I'm a full-time photographer. I know about it now and am already planning to start playing around with it.

Something that makes me sad is how DSLR manufacturers insisted on making "digital film" instead of taking the next step and creating a truly revolutionary computational imaging tool.

For example, you could set up the camera in a studio to rapidly cycle through a set of flash guns, and then import the stack into Lightroom (or whatever) for this kind of additive light editing. This could then be programmed back into the flashes to create the final lighting composition.

This kind of process is regularly used in the film industry, where the same scene will be recorded with different lights turned on. Even camera motion is possible with robotic controllers. As a random example, I believe the new Blade Runner movie had the city flyover shots made this way.

A long time back... I thought about trying to capture motion in colors. Its not particularly novel and my first attempt with color print film (using a triple exposure and red, green, and blue filters) really confused the lab because the rest of the roll looked right, but this one print looked trippy.

My "ok, I could do this with black and white" had me thinking about Agfa Scala slide film (a black and white film) and then using red, green, and blue filter packs and print to color slide paper (cibachrome). I never found the lab that would entertain the idea (and the paper was $$) before I wasn't able to get that print done.

I did play with it in digital though...

* Burney Falls - https://shagie.smugmug.com/Nature/Tricolor-time-lapse/i-kNPx...

* Wave at Ruby Beach - https://www.deviantart.com/shagie/art/Wave-sequence-tricolor...

(late addition)

* First attempt - https://www.deviantart.com/shagie/art/RGB-Experiment-Running...

Reminds me of these over 100-year-old colour photographs from Russia: https://twistedsifter.com/2015/04/rare-color-photos-of-the-r...

The photographer Sergey Mikhaylovich Prokudin-Gorsky used a similar process, with separate red, green, and blue exposures with colour filters.

In some of his photos you can see the same rainbow effect on moving objects like water or clouds...

the synthetic lighting method was actually used in some of the Half life 2 episodes in a kind of Normal maps ++ method (basically normal maps with built in internal shadowing) I wonder if valve still uses it, as they mentioned actually creating the source texture was fairly expensive and involved final gather type rendering a 3d scene with 3 colored lights :) (as opposed to just measuring normal vectors per pixel)

edit: https://cdn.cloudflare.steamstatic.com/apps/valve/2007/SIGGR...

edit edit: https://youtu.be/1ry67uHZSS0 another fascinating use of a very similar technique

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