Imaging the diatom slide using microscope 276.

This microscope images using reflected light only. The magnification of this microscope is approximately 125x.

Note the circular marks on this image. These are probably circular scratches in the objective lens produced during the grinding and/or polishing process. They are black because they refract light.

There are several optical aberrations apparent in this image: Chromatic, spherical, and field curvature are the most prominent.