Visible Light beam without fog or volumetric? Is it possible?
Yes and no. There is a way to approximate crepuscular rays in compositing using the Sun Beams Node. The manual page for the node is here: https://docs.blender.org/manual/en/latest/compositing/types/filter/sun_beams.html#sun-beams-node
Now, this is just a post-process effect, but I guess there’s an argument that all computer graphics aren’t real thus it all approximates reality to a degree. I’m sorry - it’s late. So to reanswer your question, yes, there is a way to get the effect you want, but no it isn’t physically-based.
Thanks for the info.
I use Blender now and I love it, but for years I used to use C4D. In C4D there was a button simply called Visible Light. You’d check it and viola! You had Visible Light with no volumetric at all. But I suppose you’re right, not very realistic. But sometimes you just want what you want.
As a quick history lesson, the Blender Internal rendering engine in 2.79 and before had a similar checkbox called Halo: https://docs.blender.org/manual/en/2.79/render/blender_render/lighting/lamps/spot/halo.html
Check it and you’ve got fast volumetric light rays. I do understand the move away from Blender Internal, and I expect there is a list of features on a Eevee wiki somewhere where feature parity with Blender Internal is being tracked. I’d think this one would either be checked (as Eevee supports volumetric shaders) or partially checked. Eh, I’m just rambling now. I’m very sleep deprived. Have a great day!