Bagginsbill is absolutely correct in his assertion and that fact is what prompted me to write Reality.

Lighting is 80% of your image and without realistic lighting it's very, very hard to achieve beliavable images.

The size of a light determines also the softness or harshness of the light. I see often that some people think that the harshness of the light depends on the brightness or the distance of the light to the subject. Both options are not correct. The harshness of a light depends on its size in relation to the subject. A large light generates soft shadows and a small light generates sharp shadows. 

Now, a light becomes larger in relation to the subject as the light gets closer. That's the only effect that the distance causes and it's usually the opposite of what is thought by artists who don't have photography experience.

In addition to those factors the color temperature of the light has to be beliavable and the exposure of the frame has to be set correctly. Let's take, for example, a scene set a midday, full sun. How do we control the brightness? In real life we cannot "dim the sun", that's an absurdity. Still, ask 10 photographers to shoot that scene and you will see 10 different exposures. Exposure is the way we control how much light we let go inside the camera. Not having that control is another limitation for the 3D artist.

In the pursuit of photo-realism the closer we are to the conditions of real life, the easier our job is.

Answering your question on why Poser doesn't have physical lights, the situation evolved over the years. Poser, like the majority of 3D programs developed in the past 20 years, uses a biased rendering approach. Biased rendering was designed to deal with the processors and technology available 10, 15 or 20 years ago. There were no expectations of photo-realism from the 3D programs back then so creating an infinitesimmaly smal light was no concern.

Cheers.

Paolo

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