The easiest way to do this is to change your world shader to one that uses High Dynamic Range images (HDRIs). There are many sites online that provide high quality HDRIs and you can find them by searching for "free HDRI" in your favorite search engine.
There are two steps to this.
- Download the image from a web site. Each site will have its own instructions but usually it's simply 'download image'
- Change your world shader to use the HDRI as the lighting source.
- go to the Shader Editor
- In the header change from Object to World
Enable Use Nodes
Enter this shader:
Note: I've already added an HDRI, so you can't tell, but the node with the orange header is an Environmental Texture.
Click on the folder in the environmental texture and navigate to where you downloaded the HDRI. Select it. It's a good idea to create a folder where you store HDRIs and always select your HDRI from that folder.
Switch the Shader Editor back to Object so you won't be confused the next time you edit a material.
Explanation of the node group
The first two nodes are a Texture Coordinate node and a Vector Mapping node. Together they allow you to change what part of the HDRI is behind your object from the Camera's viewpoint. Changing anything but Z Rotation will distort the HDRI, but changing the Z rotation is a common technique.
The next node is an Environmental Texture. This is the node that changes the image into a form that can be used as a Background. It has 5 imput fields:
- The image name, already mentioned.
- Texture Interpolation. Leave this as Linear
- Projection Type. HDRI images come in two formats, mirror ball, or the more common Equirectangular. Unless the site describes an HDRI as being a mirror ball, leave the setting at Equirectangular
- Where the image comes from. Leave this as Single Image.
- Color Space. Leave this as Linear
The green node is a Background node. This converts the output of the Environmental texture into a light source. The Strength Field sets how strong the light is.
The final node is the World Output node. It simply tells the render engine that this is the world lighting. Leave the one setting at All for an HDRI