Some say it takes 10,000 hours, or 10 years, to be a master of something. To create photo-real architectural renderings it takes a lot of hard work, and only a few have mastered the craft of photo-real architectural renderings. It takes a lot of screen time, more than you might imagine.
Some say that unless you are in the photo-real business nobody is noticing the subtleties that keep an image from being photo-real, but I would have to disagree. Humans have a keen sense of perception and can perceive even the smallest errors in what they are viewing, which makes them feel uncomfortable.
The uncanny valley is a hypothesis in the field of 3D computer animation which holds that when human replicas look and act almost, but not perfectly, like actual human beings, it causes a response of revulsion among human observers.
One study conducted in 2009 examined the evolutionary mechanism behind the aversion associated with the uncanny valley. A group of five monkeys were shown three images: two different 3D monkey faces (realistic, unrealistic), and a real photo of a monkey's face. The monkeys' eye-gaze was used as a proxy for preference or aversion. Since the realistic 3D monkey face was looked at less than either the real photo, or the unrealistic 3D monkey face, this was interpreted as an indication that the monkey participants found the realistic 3D face aversive, or otherwise preferred the other two images. As one would expect with the uncanny valley, more realism can lead to less positive reactions, and this study demonstrated that neither human-specific cognitive processes, nor human culture explain the uncanny valley. In other words, this aversive reaction to realism can be said to be evolutionary in origin
Our clients don't understand what it takes to produce a photo-real rendering. But, they expect something that makes them feel comfortable when viewing it, and not something that seems off, or wrong. There is a wide gamut of work, which is being called photo-real, but unless it looks like a photo, it's not photo-real.