ND FILTER APPLICATIONS
Neutral Density Filters can help with the following applications:
LIGHT SATURATION REDUCTION
When an item being inspected is surrounded by an unmanageable amount of light, using a Neutral Density Filter (ND) may be the only way to image the item. Applications that rely on dark ND Filters include imaging a welding process or looking directly into lamps, bulbs, light emitting diodes (LEDs) or other bright sources. When a subtle reduction in luminous intensity is needed, an ND Filter with a lower optical density (OD) may be the best solution. |
Before ND Filter (Left); After MidOpt ND Filter (Right)
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Before ND Filter (Left); After MidOpt ND Filter (Right)
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SHALLOW DEPTH OF FIELD
Opening the lens aperture creates a shallower depth of field but lets in more light. ND Filters allow for larger apertures to be used, while limiting overexposure by attenuating incoming light. A shallow depth of field with controlled lighting can successfully isolate an object from its background or foreground, meaning portions of the image that are distracting or could result in false readings will be out of focus. As machine vision imaging continues progressing toward more compact inspection layouts, which force the camera and lens closer to the subject, this effect becomes even more pronounced. |
OUTDOOR AERIAL IMAGING
The ND Filter is one of the most useful filters for outdoor aerial imaging. Since it serves as “sunglasses for your system,” it helps reduce light without altering color or having any other negative effects on image quality. ND Filters provide a simple way to control exposure without altering your camera’s aperture or shutter speed—both of which can have negative imaging side effects. |
Before ND Filter (Left); After MidOpt ND Filter (Right)
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Before ND Filter (Left); After MidOpt ND Filter (Right)
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LONG EXPOSURE | SLOW SHUTTER IMAGING
ND Filters are used to capture stationary elements while blurring or obscuring objects in motion. This is extremely useful to reduce frame rates, helping to remove prop blur (jello effect) and interference from high-frequency vibrations. In professional photography, it can be used to create an interesting effect with the lights. For example, when imaging a fixed street sign with moving cars. Slow shutter imaging can also be used for shooting waterfalls or sporting events. Long exposures are useful for capturing lightning strikes and can also be used for creating designs out of moving light. |