Tinto Brass is a genius at making you believe you're watching hard-core porn when you're not even close. In The Voyeur, we never really see penetration at any time, but Tinto makes you think we do. He's very clever with his camera and editing.
There is some sumptuous sensual photography on display here, and some great pix of prosthetic male genitalia, although they more resemble dildos. In several scenes (particularly with the father's full-bore erection), the dildo looks like it's carved out of wood, but Brass gets around it through clever lighting.
This film was made in 1994, before they produced prosthetic genitalia so believable that you're hard-pressed to tell the difference. I think it's now theoretically possible to make porn flicks with male prostheses. They can even make those things ejaculate. Maybe that's the wave of the future. A lot cheaper, and much faster to do.
I like Tinto Brass. He's a genial sleazebag who also happens to be quite creative. He infuses just enough 'straight' drama in his films to make you forget at times that what you're basically watching is high-class smut.