the world > physical sensation > sight and vision > optical instruments > instruments for observing > [noun] > for viewing photographs (4)
An optical apparatus by means of which photographs placed inside it may be viewed. Now historical.
An apparatus containing a magnifying lens arranged for viewing engravings, photographs, etc.
A device for imparting the effect of colour to monochromatic photographs. Obsolete.
An optical device used for viewing images recorded on a particular medium, esp. those recorded on microfilm.