| Did the great masters use optical projections while painting? Perspective Comparison of Paintings and Photographs of Renaissance Recent countries visiting this post |  |
 | 10 | United States |
 | 1 | Germany |
 | 1 | Canada |
| Did the great masters use optical projections while painting? Perspective Comparison of Paintings and Photographs of Renaissance Recent countries visiting this post | |
| 10 | United States |
| 1 | Germany |
| 1 | Canada |