Dry incubation v. controlled humidity?

[Arielle]

Can anyone explain to me the effect on the egg of these 2 humidities? And what happens to the white of the egg?? The chick absorbs and uses the yolk but what happens to the white? Sorry for the question--have read so many posts I'm feeling lost.

 

[SundownWaterfowl]

Dry incubation is when you add no water to the incubator during the first 18 days. Day 18 when they go into 'lockdown', you bump the humidity up to around 65% as you normally would. I like dry incubation. If I add water to the incubator, it seems like the eggs don't lose enough moisture and the air sacs will not get large enough.