Thanks to all re: jaggies
I see there are a lot of possible solutions to try to avoid jagged edges. I am cranking the image size up to its max prior to rendering, then exporting it to photoshop, where it's resized again to 300dpi. The edge jags are most noticeable on smooth or shiny objects. The wierd thing is that even with all this rather crude jaggedness some of th texture in the same image are incredibly fine and smooth! I have a lot to learn about this program, but it's simply the most exciting thing to come along in a good while.