That's the issue. Thick brown shells. I can see growth in all but it's pretty hazy and these old eyes are having a little trouble making out details. Saw that duck video and that was amazing!! Gonna have to configure a better candler for the next time around.
[/quote. Well with really thick or chocolate brown eggs no type of light will pass through you can use 600 or 800 grit sandpaper to sand two lines down the front and back of the egg and then spray with bactine lightly this will allow you to see through the dark eggs and monitor development now that you have done this remember that you have removed the bloom from the outer shell and these eggs need special care with hygiene during the rest of the incubation and hatching period allot of folks who hatch dark coo coo maran and other chocolate egg laying birds use this method to candle do a search on hatching chocolate eggs and you should find info and pictures on the procedure