Finally got caustics maps working I think. Final gathering. Not storing first hits in the photon map, 10M photons ~1M caustics photons, 128 max photons, photon radius 0.1 caustics radius 0.75, 8 GI samples. 5 min 5 sec

Same as previous image except first hits are stored in the photon map, took 4 min 34 sec

Same as the last image but with 10M photons, 128 max photons, radius 0.1. Took 3 min 18 sec

Final gathering with photon map storing only indirect illumination. Rendered with 1M photons, max photons 16, radius 0.25, 8 indirect samples per direct ray hit. Took 8 min 34 sec

Indirect illumination handled by the photon map, except both direct and indirect photons are stored in the map. Same parameters as the previous image. Took 1 min 56 sec

Indirect lighting handled by the photon map, where only the indirect lighting is stored in the photon map. Changed max photons to 128 and radius to 0.25. 10M photons took 1 min 50 sec

Direct and indirect illumination handled with photon maps only, same parameters as the last image. 1 min 45 sec on my laptop

Direct illumination using photon map only. 10M photons, estimation parameters: radius 0.5 max photons 256, 17 seconds