I’ve been getting a lot of hits lately for Google searches relating to Blender, nodes and vintage film colours. I haven’t covered that topic yet, but I’m guessing the traffic is finding some of my other tutorials.
And, since it’s super simple, here’s the lowdown:
By the way, this works with Photoshop too. It’s basically all in the RGB curves, so most programs (Photo apps like Aperture, as well as video like Vegas or Premier) should be able to use this. I’ll cover a bit about Blender specifically first, so just skip to the RGB part.
Basic Light Physics
This is a render specific thing. If you’ve already got a photo or video taken from real life, skip to the RGB curves below.
Light, by itself in the 3D world, is pretty silly. It’s usually perfectly white and so colours are represented fairly. The above image might look like this:
Which works for a lot of renders; it’s desired for a lot of things. However, I’m assuming for this tutorial you’re wanting something for realistic to how real life light behaves, and from there we’ll talk about how film behaves to capture that light.
As a rule of thumb, sunlight at high noon is not white but warm – it’s slightly yellow. As you approach sunset, it gets increasingly orange-red due to the bouncing and scattering in the atmosphere. The physics aren’t terribly important since new Blender has provided a handy part of the sun lamp: it can do the sky for you, and this includes light colour. It even has a few presets so you don’t have to fuss with any numbers if you don’t want to.
Turning that on “desert” we get this render: (remember, before we’ve even touched any nodes or anything) (Also notice how long the shadows are, the sun is quite low on the horizon – quite sunset-y – quite orange.)
Which gives the light a nice warmth.
But light tends to get cool in the shadows. It actually becomes more blue as it gets darker. We’ll go into the nodes for that. There are a few points to consider, though. It’s the same process, but how much you do it will define how stylized the outcome is. If you’re going for straight photorealism with a modern hypothetical camera, you’ll want a very subtle effect. Film just amplifies it.
First, an overview of what the curve actually does.
I highly encourage you to open Photoshop / Blender / Other and have some image to play with. It’ll make more sense when you can play with it. These screenshots are from Photoshop CS3, but it’s the same idea everywhere.
The curve from bottom left to top right represents the lightness of the existing pixels. If you were to, say, nudge a point 3/4s in the top right and bring it up a bit, the light parts of the image would brighten further. If you brought the bottom left point up, the dark bits would lighten up. You can combine points and create a curve that would increase contrast (make bright parts brighter and dark parts lower) or do the opposite.
This effects the full RGB spectrum equally. But, there are really four independent graphs: RGB, R, G and B. They all work the same, but the last three effect only their specific channels. In this way, you could make all the highlights redder and all the low bits bluer by making the graphs something like this:
Which is exactly how vintage film (and most Instagram effects) behaves. The lows move into the blue-purple range while the lights go into either the yellow or red ranges.
And, depending on the film type, this will vary. For maximum effect, look at actual samples from a specific film type (Polaroid, Lomo, Kodachrome etc) and try to recreate it. There are lots of bad, bad, attempts with no basis on any one film and it comes out looking really cheesy and obvious fake. So, just be aware.
For the people using both Blender and Photoshop, I will point out that the curves are on different scales between the programs. Although they behave exactly the same, Blender seems to be more sensitive, so move the points in smaller amounts.
As always, if you have any comments, questions, changes or suggestions feel free to let me know.