Shadow Catcher - how to simulate white background

[BSimon]

Hi!

I need to prepare two render versions with ceiling lamp. First with white ceiling and another one with Shadow Catcher on ceiling. Lamp should look the same on both picures.
Problem is that there are differences in the appearance of the lamp (lamp from Shadow Cather picture is darker).
How to set Shadow Cather parameters to simulate white ceiling?

File in attachement (there are also my shadow catcher parameters)

Best regards!
Szymon

[szymon.bochenek]

I found semi-solution but works good!
I can make two renders - first with white background and second with shadow catcher and use shadow catcher  render in Photoshop as mask for white background render.

Best regards!
Szymon

[burnin]

Maybe this "soulution" can help ;)
Mirror Effect in a clear white Environment

[szymon.bochenek]

Thanks burnin!
It looks more similar but not the same in my case.

BR,
Szymon