Eggs and No Veins

[Madie'sOddFlock]

I have eggs that are about 12 days along. The black blob that should be the embryo is apparent. But I've read and seen that I should be able to see veins as well. I don't know if it's because the light I use isn't bright enough, or what. This is also my first time incubating. And I'm using broody hens. So help, please.
Thanks,
Madie

 

[RodNTN]

Congratulations on your first time incubating! Do you have pictures? That could help