Two important questions

[fa2020]

Hi guys,
1) I rendered the following statue using Corona 1.7 and as you see there is an arc of white dots for no reason. I used HDRI and IES light. Why are these white dots appeared in the final image?
2) How can I ease the process of adjusting focus on the subject? Generally, I use many try-outs to find a proper distance parameter but it is not quite fine.

[NicolasC]

Hello,

1) no idea, sorry
2) I wish we could pick focus area directly in the VFB :P

[TomG]

For distance, don't forget you can use an object to set the focus distance in the new Corona Camera. This can either be an object in the scene, or a dummy object - the target object can be animated too so that the focus moves during an animation. In terms of strength of the DOF, that still comes down to the aperture etc, just as in the real world, but the focus target object is very handy for setting the distance itself :)

[TomG]

On the arc of white, not sure of the cause, one question comes to mind - does it change with the DOF? If you strengthen / weaken it, or change the distance, does that ring move? Does it go away if DOF is disabled? Is it still there with a default CoronaMtl?

[NicolasC]

For distance, don't forget you can use an object to set the focus distance in the new Corona Camera. This can either be an object in the scene, or a dummy object - the target object can be animated too so that the focus moves during an animation.

Thank you for the reminder, TomG :)

[fa2020]

On the arc of white, not sure of the cause, one question comes to mind - does it change with the DOF? If you strengthen / weaken it, or change the distance, does that ring move? Does it go away if DOF is disabled? Is it still there with a default CoronaMtl?

IES light is the cause. I found it.

[TomG]

Glad you got it fixed, and ty for letting us know too! Always handy in case anyone else runs into the same kind of issue, gives a good pointer on where to look for the possible cause :)