Some parameters render very slowly and in a grainy way, even though the DE looks simple and uncluttered and the surfaces are smooth and shouldnt be grainy, i have to put the raystep multiplier right down to 0.02 to get a smooth pic and the render takes 3 hours for a high quality image.

What are the reasons for a mix of formulas going slowly? i.e. i know devide and exp are slow, can you explain practically what formulas etc will tend to be slow for those reasons?

what other reasons?

any tips and tricks to make slow formulas go faster? why do i have to put raystep multiplier to 0.025?

i.e. here is a slow one, why is it slow? any ways of speeding up the rendering?

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