SEM and ESEM only show the surface. Internal structures seen in many transparent specimens are not visible. Soaked in oil or water even agglutinated forams show internal structures. As a result the SEM-images differ substantially from the real appearance, thus not representing, what should be shown.
Asterigerina rotula (Kaufmann, 1867), Eocene, Moravia, Czech Repbulic painted by Miroslav Bubik, Czech Geological Survey and SEM of Asterigerina guerichi Franke 1912, Eocene, Northern Germany.
While the SEM shows details, the drawing illustrates the internal structure.
Optical Images often lack quality
The optical images of Asterigerina guerichi Franke 1912, Oligocene, Kasseler Meeressande lack quality as many optical images. The smaller the size the more difficult gets the optical imaging. The main problem is caused by the thickness of the forams. The area of sharpness is very small, so that many images need to be made and stacked together. Thus optical imaging is far less used than SEM imaging.
Conclusion
Drawings should nowadays still be seen as a proper means in foram-illustration and should be used more. A combination of drawings, SEM- and optical-imaging is recommended to achieve the best result in optical representation:
Cibicides lobatulus (=Lobatula lobatula) (Walker & Jacob, 1798), recent, from sea around Smoegen, Sweden.
Cibicides lobatulus (=Lobatula lobatula) (Walker & Jacob, 1798), recent, from sea around Lizard, Cornwall, UK.
Cibicides arguta Bykova, 1954, Eocene, Moravia painted by Miroslav Bubik, Czech Geological Survey, Czech Republic
