I meant that the pixels look the same while the render time was decreased - which is goodgrinsegold wrote:Aethelraed_Unraed wrote:..., with no discernible difference in the result.
Then it is most likely not the fog but the fire. Is its emitting value far over 1? Dial it down and cheat with a spot-, point- and/or an arealamp. And the is-camera-thingy of course (camera gets more emittng power to be able to easily separate it later when applying glares if needed).
Anyway, I've tweaked everything I could think of and made another attempt - this time I got much better results, although with a render time of a little over 4 hours. It's still got the strange shadow artefact you mentioned, if I can find the time to render it once more I may attempt to locate that problem (and tweak some other small things, mainly lighting).The new image is in my edited first post.
Anyway, I'm still not quite sure what caused the excessive render times. I've since done another image with much more fog (http://aethelraedunraed.deviantart.com/art/Grandfather-s-Hel-ride-565652661) which rendered in 40 minutes. It probably was the combination of fog, fire and complex lighting.
