Are you using Apophysis or JWildfire? In Apo try render settings of Quality= 6000, Filter Radius .4-.6 and Oversample 2. Check the Post-process box as this will give you the option to readjust Brightness, Gamma and Filter-Radius if they weren't just right at the front end.
I used apo before, but that was a long time ago. Using JWildfire now. I assumed it was merely a process of adjusting those to make it clearer, but now I know which direction to go. Thank you for the tip.