"Directional" vs.

Both the "eye" and the "camera" have directionality, meaning that they can only sense light from a certain direction.
What kind of images can be obtained when these are combined with LEDs or lens-focused illuminators with strong directivity?
The light only comes in where the "directivity" happens to match. If the directionality deviates even slightly, the amount of light will vary greatly.
This is used in the "method of illuminating a wound by using projection illumination, etc.". The camera catches the light that "accidentally" shines due to the shape of the wound, and it can be said that the light is somehow made to shine by changing the angle of the object and the angle of illumination. Especially when combined with a "hand," changing the angle of an object makes it darker or brighter, making it very easy for the human eye to catch.
When inspecting with a camera, it takes time to image various angles, and it is also undesirable for the image to change significantly with subtle changes in the lighting angle. After all, it is easier to stabilize the illuminator combined with a "camera" that has strong "directionality" if it is "non-directional = scattered light," and it is easier to take a single shot of a scratch if it is taken in black.
In other words, it is necessary to reconsider which is better suited for image processing: "LEDs, which are dark unless they have directionality by concentrating light," or "fluorescent lamps, which have scattered light and high light intensity. Indeed, we often hear stories such as "I could see well with fluorescent lamps + visual inspection, but not with LEDs + image processing," or "I could see well when I replaced LEDs with fluorescent lamps. We believe that this is the result of "scattered light + high light intensity.
Even fluorescent light fixture manufacturers are saying, "LEDs are the future, and fluorescent lamps are shrinking. However, since the objects to be inspected are becoming larger and larger, we believe that it is still difficult to abandon fluorescent lamps.