Lighting is a big deal.
It can mean the difference between an image that feels unnatural, and one that feels alive and welcoming:
But unfortunately, most outdoor lighting setups look pretty terrible.
Why most outdoor lighting looks bad
The most common approach to outdoor lighting is to use a sun lamp and a blue environment light. Which is a step in the right direction, but it's too simple. Because - as with many things in CG - the real world is much more chaotic.
A sky isn't just blue. Thanks to clouds, and the physics of light, it's a million different shades of blue, white and yellow. All with differing amounts of saturation and value.
Run an eyedropper over a photo of a sky and you'll see what I mean:
That's a huge amount of variance for something most of us perceive as "blue"!
When your sky lacks this detail, it impacts not only the lighting but also the reflections.
And since all objects are reflective, a solid blue color looks pretty laughable in a reflection:
Simply put, without a real sky, you're missing out on glorious detail in the reflections and the lighting.
So how can we get all this extra complexity in our renders?
The Solution: HDRs
HDRs are a completely different approach to lighting. Instead of using lamps, it uses a single image to light the scene that looks like this:
And while it looks like a standard photo, it actually contains valuable light information (captured in multiple exposure ranges) that your rendering engine can use to create light:
(Remember: this is without any lamps whatsover! It's controlled entirely by a single HDR image.)
They show up in reflections too:
HDRs are the most photorealistic lighting solution, because there's no fakery. It's taking an exact lighting profile captured in the real world, and bringing it into your 3d software.
That's the reason they're used by hollywood and most architectural renderers.
But unfortunately HDR Skies aren't cheap. They typically range from $10-30 each online, which means a modest collection of just 10 Skies would cost $100-300.
And all are available at a whopping 15,000 x 7,500 and 12 EVS :)