I extended josiathegreat’s version for soft shadows(using multiple lights to gain soft shadow effect) and made a simplified .blend with 4-sample and 7-sample soft shadows. Sample count can be increases, but it costs performance a lot. Also multiple samples can have multiple strengths. To gain correct effect, samples around main lamp should make a value equalient to 0.5(as the main lamp makes other 0.5). Or either the color brightness of main lamp can be increased too. This shadow sampling method makes accurate soft shadows that are harder when closer to surface and softer whan further from it.
In .blend there are 4 scenes - one for sun and one for spot and HQ and LQ versions for each.
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why not just use the variance lamp?
It has worse performance(unless we sample this up too much) and, although it has smoother blur, it has wrong shadow effect closer to surfaces(it fades and gets lighter instead of getting stronger and sharper) so that this method is better in my opinion.