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I aligned the sun of the HDRI with my scene and strengthen it a bit. But the result seems a bit weird to me. I have a real big sunbeam in the middle of the scene that generates clipping on the plane it strikes.

The scene it self is extreme dark at the moment and increasing the strength will result in clipping all over the floor.

I think I need to make the radius of the sun(light) bigger. Can I do this in blender or do I need to adjust the values of the HDRI ( if so, how? )

Example of the clipping:

enter image description here

Node setup for HDRI:

enter image description here

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Judging from the middle grey-ish values on the left and right, something seems incorrect here.

That is, I suspect the albedo values on your floor are too high. We should expect that the direct sun source, which is relatively small, would project sharp and direct heavy light through all three windows. Instead, we barely have middle grey, yet on the centre window, the high energy pixel region is the cumulative effect of fresnel and albedo reflecting the light directly, as opposed to illumination. Hence, wrong values, and too low of an HDRI strength.

I also see skew to yellow there, which suggests Filmic isn't set as the view, or you have a degree of processing that is breaking things. The false colour LUT shouldn't be used with anything other than Filmic.

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  • $\begingroup$ Well I was looking in the wrong direction. Thanks for pointing that out! $\endgroup$ – S.Visser May 13 '18 at 20:50
  • $\begingroup$ Albedo's are damn tricky things to wrap one's head around. That is, when you are in a painting application, you are looking at a colour that is being projected at you face from the diodes. The same is true when selecting albedos, but in terms of what is represented in the scene, the numerical values are frequently way off. Best advice is to search for common albedo values online, and try to make the average luminance of the colour you are wanting equate with the albedo value. If this seems complex, you can post another question and I'll try to answer it more clearly. $\endgroup$ – troy_s May 13 '18 at 21:41

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