Use the same lighting conditions as when a person inspects.

Appropriate lighting conditions will vary depending on the application, though,

Choosing that lighting is not easy unless you are experienced.

I've mentioned the key points many times on this blog,

Use the same lighting conditions as when a person inspects.

I think that is the basic idea.

Just because you can't see the defects you want to see,

And if you bring the lighting closer, it's even more difficult to see,

It can increase the amount of light and make it extra difficult to see.

If the defect is such that it can be seen well in natural light,

It is better to inspect the camera without lighting and with increased exposure time.

It can be seen clearly.