Point light with a light_decay filter and atmosphere_volume.
Just one more thing. What I'm trying to do is place this the light so its shining through my model's front glass lens - I created a sphere, applied glass material but it lights up the inside of the model but cannot be seen through the glass. Does it need to be completely inside is solid object with the lens on the front like say a cylinder and front cap being the lens? Thanks
What happens if you increase the exposure of the light?
I tried a simple example here with atmosphere_volume (on the right caustics is enabled (standard_surface.advanced).
Have you tried adding a gobo filter to adjust the falloff of the light?
Maybe a spot_light would work better to control the light appearing outside of the geometry?