the main things to do are: check the second "light thru transparency" setting increase photon count to 100000 or more I would advise unchecking gamma, as the image is too bright on my monitor, but it may look correct on a windows machine. I would suggest leaving the filter where it is, as increasing it may cause problems. in addition, ya can: increase anti-aliasing/lighting quality to best change all accuracies to 1 pixel uncheck interpolation check "improved edges" change photon accuracy to 30% the additional will slow the render wayyyyy down, but may not improve it enuff to justify the wait. it may also speed it up to uncheck the skylight in an indoor scene, but if the default had it checked, then it may be needed.