Trouble candling ?!

[ModernGameGrl]

Has anyone ever had trouble with their candler being correct/accuarate? I just candled my eggs that are 6 days along. I had 12 silver wayndotte eggs my candling light lit them up nicely but it didn't look like much was happening except for in maybe two. No veins just bright clear eggs. In my EE eggs some where too dark to see through and some I can see lots of good veins.
Because the Wayndotte eggs didn't look promising I decided to open two eggs up and see what was going on. To my dismay when I opened them they BOTH had chick in them that where developing right on schedual. Anyone else ever have this happen? I double checked the eggs before I opened them too but they where clear. Why would I be able to see veins in my green and blue eggs but not in my tinted/light brown eggs?

 

[Ridgerunner]

I never take any eggs out of the incubator until I candle when I go into lockdown unless oen is going bad, and I rely on smell more than anything else for that. Unless an egg is going bad, why would you?

I can see inside some of my eggs pretty well; some, especially the darker green ones, are practically impossible. They can have different porosities or shell thicknesses. It's not just the color of the eggshell that causes differences. The eggshell color goes on in different ways too. With some of them it is laid on the outside of the shell. Some of them have tinting all through the shell. We use different candling techniques and some batteries are fresher than others, but there are just basic differences in the eggs that make some harder to see in than others.

I usually candle after seven days and mark the eggs. I put a black check on the ones I think are good and a red x on the ones I think are not. Some don't get marked at all. I'm probably right about 95% of the time, which means I'm wrong maybe 5% of the time.