Hey that's cool!
My candler is homemade too but not nearly as fancy...
I have a flashlight with four layers of thick foil duct taped over the lens with an appropriate sized hole (about 1/2 inch) in the foil. It works well and I can change the foil and hole size according to the egg size (I hatch quail too).
You can buy a commercial candler ... they are suppose to be great.
My candler is homemade too but not nearly as fancy...
I have a flashlight with four layers of thick foil duct taped over the lens with an appropriate sized hole (about 1/2 inch) in the foil. It works well and I can change the foil and hole size according to the egg size (I hatch quail too).
You can buy a commercial candler ... they are suppose to be great.