Replicand thanks for the explanation of bucket size. I found most of this by experience and trial and error.  Here is my question does your render dimension size have an effect on the quality or time to render. Of course I know that a very large render 4000x4 000 takes longer. But what I mean is would it make a difference if I used render dim. of 2048x2048 instead of 2000x2000. I used to render at dims such as 512x512 or 2048x2048 but started using 2000x2000 or 1500x1500 or whatever I wanted. What I do now if I want very high quality is render at the max size I can without a crash message and later reduce the image in Photshop to improve the quality. Example such as rendering at 2000x2000 and reducing to 1000x1000  in PS. The final image reduced image does appear less pixelated and smoother. Do you have any thoughts on this or if I am not doing this the best way or so. Thanks