Hi Robyn, I just had a quick look at this.

I don't think you want to assign the IBL light to 'Sky'. The IBL is sufficient to define the environmental lighting without invoking the 'Sky' processing too.

The attached example shows the sky clearly defined by just using an IBL.

Your image had much more contrast too, but I haven't attempted to emulate that on the assumption that the sky was your primary concern?

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