How do you set up lighting for camera-based egg inspection?

How should the light be positioned?

A good setup starts with the light source, before any adjustment to the camera. Follow this order:

1. Position the light source to illuminate the conveyor from above, without pointing directly into the lens.
2. Use a large, soft source, so that light reaches the shell from several directions at once.
3. Avoid direct light on the shell, because a point of brightness can be read as a stain.
4. Check the shadows from the rollers and the edges, and adjust the source until they do not create dark lines across the eggs.
5. Fix the source to its mount, so it does not move with vibration or knocks.

The light should be even across the whole camera field. If one side of the conveyor is brighter, the same shell gets different readings depending on where it sits, and the result depends on the place, not on the egg.

How do you control glare?

Glare is a point of brightness on a smooth or wet shell. It has the shape of a stain, which is why it is one of the common causes of a dirty egg being wrongly classed. Fix glare in the setup, not with a higher limit, which would let real dirt through.

1. Watch the conveyor with real eggs and locate the bright spots on the shell.
2. Change the angle of the source or the camera until the glare leaves the area where the egg is measured.
3. Use a diffuser or a light surface to spread the light before it reaches the eggs.
4. Check the glare on the brightest eggs, which tend to be the smoothest or the wet ones.
5. Save images with glare and redo the setup until the glare disappears.

Wet or freshly washed eggs shine more. If the line washes eggs before the camera, test with them too, and not only with dry eggs.

How do you keep the lighting stable through the shift?

Light changes over time: lamps age, dust builds up and someone may knock the mount. A small change is enough to shift the result. That is why stability is treated as a routine, not as a one-time adjustment.

1. Switch the light on for the same time before the first batch, so the intensity has settled.
2. Keep a reference photo with the position of the source and the camera, and check it at the start of each shift.
3. Clean the lamp, the diffuser and the lens at a fixed time.
4. Replace the lamp when its colour or brightness changes, and record the replacement.
5. Compare images from the start and the end of the shift using the same known clean eggs.

How do you test whether the lighting is ready?

A test with known eggs shows whether the setup is ready before any limit is adjusted. The eggs must be clean, verified by your team, and kept out of the set used for calibration.

1. Set aside a sample of known clean eggs, verified by your team.
2. Pass these eggs through the conveyor with the current configuration, without changing anything.
3. Count how many clean eggs were classed as dirty or cracked.
4. Look at the images of the wrongly classed eggs and identify whether the problem is glare, shadow or real dirt.
5. Adjust the light, not the limit, and repeat the test until the clean eggs pass.

Once the light is stable, use the calibration checklist to adjust the limits one at a time.

What can lighting not fix?

Good light improves what the camera sees, but it does not let the camera see inside the egg. Hairline cracks, the air cell and spots inside the shell stay out of reach of an ordinary camera. For those, candling or another method is needed.

For the reasoning behind each item, see lighting for egg inspection.

Frequently asked questions

Does the light need to be very strong?

This checklist gives no intensity values, because the right level depends on your setup. What matters is that the light is diffuse, even and stable through the whole shift. A stronger but direct light usually creates more glare than a soft, well-spread light.

Do brown and white eggs need different lighting?

Not necessarily. Shells of different colours reflect light differently, so the setup should be tested with both types of egg before the configuration is released. Record the result for each type, so you know whether any specific adjustment is needed.

How often should the lighting be checked?

Run a check at the start of each shift, using the reference photo and the test with known clean eggs. Clean the lamp and the diffuser at a fixed time and record every replacement. If clean eggs start being classed as dirty, review the light before touching the limits.

Sources

1. Como o Vigiovo classifica ovos sem IA / How Vigiovo grades eggs without AI, Vigiovo