When I look at my Sto. Rosario I know there's something wrong with the proportion. Typically if you ask the sculptors, a 4ft santo should be around 8 ulo or 8 heads (pertaining to 8 times the size of the image's head). My Santo Rosario is more than 8 heads and yet in a huge hall the body still looks too small for the image. I theorize its because of the Rostrillo or the sun-like metal frame around the face of the image which makes the head look bigger than its actual size. I know sculptors employ visual tricks as well, part of human visual perception that they need to make adjustments to make images look more realistic. For example, I know for the Pieta the image of the Blessed Virgin is made larger than the Image of Christ so that it will not look too small in relation to the body of Christ and secondly to support the image of Christ.
So how to go about this...I try to solve this puzzle with a very crude solution, using the principle of the "ulo":
The La Naval Image
Unfortunately there is no book or information source which lists down the measurements of the La Naval in complete detail. So I find this useful.
Note however that this is not conclusive, more approximations. The variations may be due to the dress of the image, sometimes it is extended a couple of inches.
Next question is how to apply this and compute for the correct proportion...