I have a large environment texture of space that I'm using as the background of my scene.
However, when I try to use it in my render, I can only see a tiny part of it.
I want to scale down or "zoom out" on the texture, so I can see more of it in the rendered area. I tried to use a Mapping node and scale it that way, but it did nothing (I could rotate, but not scale).
This is my node setup:
Vector Mapping node is the correct way.
Make sure you are using an Environment Texture node connected to the Generated socket of a Texture Coordinate node. Then use the Vector Mapping X or Y scale to control it.
The trick is making sure you scale only in one of the three axis at a time, otherwise it will yield no visible effect.
Also have in mind that this will introduce some stretching distortion that may be more visible in certain directions, as spherical environment textures can't really be "zoomed out" in the traditional 2D image sense.
Correctly zooming out would require actually moving the physical camera in relation to the background subject and the image would need to be captured again from a different point in space, yielding a slightly different perspective. This cannon be correctly simulated with bare image transforms or manipulation, and is thus an approximation.
The scale mapping solution only works if you don't have to look around with your camera, otherwise you will notice the sphere-like background image has been stretched.
A correct way to do this scale is actually changing the Field Of View (or Focal Length in blender) of your camera, for this:
or
Another way I would try is to tile the texture, make the texture tilable in photoshop, then set it to half scale, so the image repeats, this works best with backgrounds that you don't have a ton of unique details or don't move the camera around to see the repeating image. The way I would do it is to add a wider additional part to the image, of say just stars, which will then compress the part you want to see into your field of view.
