Microscopes with lens filters

Light filters

— light filters used in the illumination system change the characteristics of the light entering the preparation and further into the eyepiece. This allows you to adjust the lighting to the specifics of a particular situation. Most microscopes use a holder for replaceable filters, however, there are also models with a built-in turret disc, which has a set of built-in filters.

And here are some of the most popular types of such filters nowadays:

— Blue colour. Used to give the image a cooler tone. It is relevant primarily in microphotography — in cases where the preparation is illuminated by an incandescent lamp or a "halogen" with a pronounced warm colour of the glow.

— Yellow colour. It is used both to give the image a warmer shade, and for some studies — in particular, to detect defects on metal surfaces.

— Green colour. Improves the efficiency of aberration correction in achromatic and planachromatic lenses. Recall that such lenses are installed in most modern microscopes, and they eliminate distortions best of all in the green part of the spectrum. Also, a green filter can be useful for phase contrast studies — for similar reasons.

— Matte (diffuser). White colour filters that do not change the colour of the light, but provide additional dispersion. This can be useful, in particular, when working with low magnification lenses.

— Neutral. Filters that reduce the brightness of the backlight, but do not affect the hue of the image. They can be useful, in particular in microphotography, if the preparation is illuminated too brightly and the camera does not have a sufficiently fast shutter speed.

— For coloured preparations. Light filters that improve the visibility of individual colours. They do not colorize the image in a certain hue, unlike regular colour ones — instead, they highlight a certain colour and muffle the rest.

— Fluorescent. Filters used in fluorescence microscopy. They are divided into two types — exciting (they separate UV radiation from the general backlight spectrum to illuminate the drug) and closing (protect the user's eyes from ultraviolet radiation and at the same time let the fluorescent glow of the drug pass through).