Can someone advise me on duck egg air sacs? Plz :)

[Kelllynnl]

this is my first time incubating duck eggs(I’ve done 2 chicken hatches). Can someone let me know how the air cells look? For the humidity I am trying to go by air cell size. I had a good hygrometer last year and it broke- it would read 4% lower than what the machine said - so with that in mind the humidity on the machine for the first 7 days was 52 then day 9 I lowered to 48 and day 14(yesterday) I lowered to 43. They seem small to me. I am not misting(the research I’ve done shows that only needs to be done if cells are too small). I could see last night some little bills and webbed feet . Any advice is appreciated
ETA the eggs are Rouen, khaki and runner - I do not know what is what as a farmer I know gave me them to hatch

 

[iluvsedward]

Heres a great article on humidity. Better to start out with low humidity and raise it than high humidity and try to lower it.

https://www.backyardchickens.com/articles/incubation-humidity.73386/