Are you talking about "Render Studio"??
That's the only one I can think of, I have this one but haven't heard of "portrait studio"..
Anyway, it could be this, Render Studio was set up to use in Vue 6.
When Vue 7 and upwards came out, e-on changed something in the lighting set up which had a detrimental effect on the lights in Render Studio plus some other similar products, "Interior Pack" for example.
Someone did post a workaround for the lighting change, you'd have to do a search for it because I can't remember what it said, I just went back to using Vue 6 if using Render Studio instead of 8.5.
That said I haven't seen this issue when using it, but then it could be a different product..

If you don't mean Render Studio then just ignore all the above..LOL, not that it helps you much anyway..

Injustice will be avenged.
Cofiwch Dryweryn.