Candling the egg

[Anyfoot]

Hi

Got 4 Homeana eggs in incubation now. The 1st 2 eggs I didn't diapause(maybe was in the ground for up to 2 wks).
These 2 eggs have been in the incubator for 32 days now. At what point will I know if they are fertile or not. Any advice on candling techniques would be much appreciated.

Thanks

Craig