In image processing systems, depth of field (DOF) is one of the most critical components of achieving clear, high-quality images. A camera’s field of view, focal point, and the type of lens used directly impact image quality and the precision of production processes. Therefore, choosing the right camera and lens is crucial for production efficiency and quality control.
In this article, we will examine in detail the advantages of cameras with field of view, focal length, depth of field, and increased depth of field.
What is Field of View?
Every camera has a field of view at a specific distance. This field of view determines the image size that falls on the camera’s sensor and can be altered by different lens types. When the distance between the camera and the object it focuses on is kept constant, different lenses are used to change the field of view.
- With C-Mount lenses, the field of view can be adjusted with options such as 6.5mm, 16mm, 25mm, 50mm, and 75mm.
- With integrated lenses, different angles of view can be achieved using Wide, Medium, and Narrow lenses.
For example, cameras with different lens types positioned at the same location will provide different fields of view, even if their positions remain fixed. This makes camera selection based on the imaging sensitivity required on the production line critical.
Focus and Clarity
A camera requires focus to achieve a sharp image. When the camera focuses on a specific plane, objects on that plane appear sharp. If the distance between the camera and the object remains constant, the image maintains its sharpness. However, if the distance between the object and the camera varies, blurring and loss of focus occur.
For this reason, while standard cameras are sufficient for objects operating at fixed distances in production processes, more advanced lens and camera solutions should be preferred for objects with variable distances.
What is Depth of Field (DOF)?
Depth of field is the range of distances within which a camera can achieve sharpness, relative to the point at which it focuses. An object appears sharp as long as it remains within this range, but the image becomes blurry as it moves beyond the depth of field.
Every lens has a focal length tolerance that it offers at a specific distance. This tolerance range varies depending on the lens type, angle of view, and camera-to-subject distance.
Examples:
- The Sensopart V20 Wide lens: Provides a 130.91 x 98.18 mm² field of view at a distance of 160 mm. It offers a depth of field of 97 mm at this distance. This means that clarity remains unaffected at 35 mm closer to the camera and 62 mm further away.
- Sensopart V20 Medium lens: Provides a similar field of view from a distance of 311 mm and offers a depth of field of 102 mm.
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Sensopart V20 Narrow angle lens: Achieves a similar field of view from a distance of 540 mm and provides a depth of field of 158 mm.
These examples show how different results can be achieved with different lens choices on the same camera.
Methods for Increasing Depth of Field
Depth of field can be increased not only by changing the lens, but also by changing the distance between the camera and the subject. For example, as you move further away from the subject, the depth of field can increase to 197 mm.
However, there’s a critical point to consider here: resolution. The number of pixels per millimeter decreases as you move further away from the subject. For example:
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At a distance of 540 mm, there are 11,013 pixels per millimeter,
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At a distance of 600 mm, this value decreases to 9,885 pixels.
Therefore, it should be kept in mind that there may be a loss of resolution when increasing the depth of field.
Enhanced Depth of Field (Enhanced DOF)
Some cameras offer increased depth of field (Enhanced DOF) compared to standard models. These cameras expand the focal tolerance range, providing greater flexibility.
For example:
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While a normal medium lens camera provides a depth of field of 102 mm at a distance of 311 mm,
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The same camera with increased depth of field offers a depth of field of 223 mm.
In another example:
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While the tolerance of a camera with a normal depth of field is about 114 mm,
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In the model with increased depth of field, this value increases to 257 mm.
This difference provides a great advantage, especially in production lines where the distance of objects to the camera constantly changes.
In industrial imaging and automation systems, depth of field is directly related to correct lens selection and camera positioning.
- If the distance between the subject and the camera is not constant, cameras with increased depth of field should be preferred.
- For budget-constrained projects, it may be more beneficial to choose narrow-angle or medium-angle lenses rather than wide-angle ones.
- Furthermore, the camera-to-subject distance should be set correctly, taking into account resolution requirements.
Correct depth of field management reduces the margin of error in production and ensures reliability in quality control processes.
You can contact our experts to get more information about SensoPart cameras and depth of field.