The jail project, he said, not only required special filters but also bars over the ventilation ducts.

Using special filters, they detected mostly extreme blue light from the object and some other wavelengths, or colors.

As an extra safeguard against the poison, Tom added special filters.

The dissection takes place under a hood with airflow forced up and out of the room into special filters.

During a hemodialysis session, your blood flows a little bit at a time through a special filter inside the machine.

The three of them work on the car, and convert it to run on vegetable oil using a special filter.

There are special filters that must be used with film that is sensible to infrared light.

For photography only in the near UV, special filters may be used.

To do so without a spectrometer would require you to get a special yellow filter.

Some earlier attempts to get a single image involved use of a special filter.