No shadow casted on white solid background

[jacquesKWQBQ]

Dear community,
When I render on a light gray solid background I get nice shadows ( ground plane turned on ), but the lighter gray I go with the background colour, the lesser shadow is casted and when I go all the way to plain white, there seems to be no shadow at all any more.

The goal is to create a pack shot of a product, which has to be on a perfect white background ( or transparent ). Note that I also tried to create a white "floor" component and that will indeed cast a nice shadow, but that plane will never render as plain white. I also tried to use a non white background ( even with environnement as bg ) and then render with transparent background turned on, but then again, no shadows.

Is this expected behaviour ? What am I missing ?

[jacquesKWQBQ]

Did some more investigating. Here is a render with no environnement brightness using an emissive face only and "environnement" as background:

Now, same setup with "white" background:

Is this expected behaviour ?
I might have a wrong understanding of what it means to change the background ?

( btw, rendering this with transparent background gives the same result )

Can't I have a plain white background but still have the shadow rendered "as if" there was a ground plane. Isn't that the idea ?

[jacquesKWQBQ]

Just to make sure I wasn't having some unrealistic expectations about rendering on white background, I tried Onshape for the first time ever, and this is my first render with the default scene setup:

This is exactly what I want / need !
Even rendering with transparent background I get exactly what I was expecting: object on transparent background WITH shadows.
Is that simply not possible in F360 ?

Is this where I switch to a different CAD program, or am I indeed missing something ?

[TrippyLighting]

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@jacquesKWQBQ wrote:

Even rendering with transparent background I get exactly what I was expecting: object on transparent background WITH shadows.
Is that simply not possible in F360 ?

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Nope, a render with transparent background AND shadows isn't possible in Fusion.