What's the trick to this? Do you need a more powerful light? I have a Brinsea Maxi II which is clear and tried this. I couldn't see anything in the eggs at all.
The trick is aiming the light in the right direction, with the eggs laying in the right position. Takes a little practice and experimentation. Also the type of eggs will make a difference. Duck eggs are nice and translucent. Some shells aren't so easy to see though. Also a very bright light (200+ lumens) in a dark room helps. I have a Brinsea Mini too, and I can do it.