Default illuminations: (a) and (b) shape can be perceived although illumination on blade is too flat and can be enhanced; some details are missing in the base of the blade and shield; 
Optimized illuminations: (c) and (d) perception of blade shape and material is enhanced, details missing in previous images are more prominent.

Default illuminations: (a) front cherry lacks highlight, while highlight on back cherry is very dim; Both cherries somewhat lack shading gradation and 3D appearance is of limited prominence; Some edges around the contact point of front cherry and stem are invisible; Stems appear dark and hardly any shape information is conveyed. (b) {}``contradictive{}'' illumination, where 3-D impression is lost due to the excess in illumination directions; Some edges between the cherries and between front cherry and stem are not prominent enough or even invisible; 
Shape information of stems is lost due to too uniform shading. 
Optimized illuminations: (c) highlights and shading gradiation on both cherries and stems convey shape information and creates a vivid 3D impression; All edges are prominent; (d) shading on stems suffer from the fact that primary illumination arrives from above (polar angle = 56 degrees) and is somewhat deficient, but still improved relatively to default cases; the cherrires have similar qualities to (c).

Default illuminations: (a) and (b) introduce almost uniform shading on both the blade and hilt, and fails to communicate shape and material information, as well as some fine details on the hilt. Edges between hilt and shield are insufficiently prominent.

Optimized illuminations: (c) introduce major improvement in blade and hilt illumination, but at the cost of neglecting the shield, where shape information is lost in the dark shade; (d) suffers from the same deficiency, although more light reaches the shield; Adding a second optimized light (e) enables proper illumination on the shield too.

Default illuminations: (a) fails to display the the different 3 levels of the boat's floor: all three are displayed in constant dark intensity and edges are invisible; this deficiency occurs also with the top right face of the boat's frame; Back of the chair lacks any shading gradients yielding in poor communication of its curved shape; (b) introduce too uniform shading resulting in reduced 3D impression; Floor levels are hardly noticeable; Some edges on boat's side are lost; Fails to clearly display the engine construction on the back. 
Optimized illuminations: (c) All edges are visible; Floor levels are clearely sepatated due to different shading intensities and more prominent edges; Shading gradients on the back of the chair help to communicate its curved shape. All parts of the engine structure are conspicuous; (d) Similar qualities to (c), however engine structure is somewhat less conspicuous.

Default illuminations: (a) illumination is too flat on side of ship's body and on back sales. some details appear blurred and edges at front and back sales are not prominent enough; and (b) almost uniform shading on most ship's regions. 
Optimized illuminations: (c) and (d) introduce major improvement in both ship's body and sales; Adding a second optimized light (e) enables highlights on sales.

Default illuminations: (a) left side appears blurred and details are lost. Details are also lost in the three surrounding pannels and top part of the chimneys; (b) extra illumination causes the entire image to appear blurred. 
Optimized illuminations: (c) and (d) introduce a major improvement on the left side, pannels and chimneys; some minor deficiencies are found on the wings of the wheel, where not all edges are sufficiently prominent. Although this is mostly due to insufficient geometry specifications of the model (yielding problems with the normals), adding a second optimized light (e) is still able to overcome it.

Default illuminations: (a) dark regions on most finger bones hide fine shape and geometry information; (b) here shape information is deficient due to weak or missing shading gradients on some of the finger bones. 
Optimized illuminations: (c) and (d) successfully communicate the geometry of the finger bones.