Which part is the air cell?

[BucksBoo]

Pekin duck eggs. Day 2 incubator. I’ve just learned about watching the air cells. Which part is the actual air cell? I’ve marked on the egg the two places I’m not sure of. All 3 images are same egg.

 

[Ms Biddy]

It is usually easier to see the air cell when you candle the fat end of the egg. I personally don't recommend candling during the first few days of development since the veins that are forming at this time are very delicate. I check and mark air cells starting on day 7.

 

[aart]

It is usually easier to see the air cell when you candle the fat end of the egg.

Yes^^^.
I candle eggs and mark air cell before setting them in incubator,
then candle and mark cells on days 7-10-14-18.