May have been mentioned before but why do the health/shield bars not show a 1:1 ratio of bar space ?

The Health bar seems disproportionally large compared with the shield bar. Before I realised I thought that the ships and therefore the weapons I was using had less effect on shields.

At times making out the difference between 30 to 70% shields can get a little tricky on the frigates and cruisers at a glance, makes shield repping with a dunvo at the right moment just a little harder than it needs to be.