These pictures were taken on daylight film.
Illumination is tungsten light from the lamp.
The uncorrected image on the left is too yellow. An 80A filter was use to color correct the image on the right. When using print film, this type of lighting problem can be corrected during printing. For most color pictures, no filter is necessary when you use a film with the light source for which it is balanced. However, there is one filter that many photographers like to have on hand.