تصويرالمتحجرات -٢'- مركبات معدنية وصخور .. مجلة فن التصوير اللبنانية _ ع٣٧

Photographing fossils -2'-
Mineral compounds and rocks

Fossils.. a new facility that you go to for photography in the jungle or in similar locations, and these fossils of various types should be identified with identification of the circumstances of their formation and therefore the methods that must be followed for photographing them.

For small, static subjects that can be easily moved around, the direct camera setup is more useful than the lighting arrangement. There are four things to consider:
(1) Strength - to be sufficient to allow a small aperture of depth of field.
(2) Direction - Traditionally, the main light is usually directed from the top left or top of the image, and it is possible to add other fill lights.
(3) Dispersion - Less dispersion reveals fine details of structure, and more dispersion is better for overall shape and color gamut.
(4) Reflection - Reflectors - White Cardboard, Silver Foils, Mirrors - Essential to make accurate adjustment of shades.

There is a great discrepancy between the advantages of geological samples because the conditions that were formed as a result of them were not similar at all, so it is necessary to treat each sample according to its own characteristics and adjust the lighting to show these essential characteristics. We always have to choose good samples among their kind, aluminum silicate crystals, for example, are often found intertwined - that is, overlapping, and it is worth looking for this feature, as it appears in it clearly.

Mineral compounds are one of the basic constituents of the earth's crust. Each of them has its precise chemical content. When the mineral compounds are allowed to freeze freely out of their previous state as a solution, they form crystals with flat shapes and sheets that distinguish them from the concept that typical crystals are rare and most mineral compounds grow as agglomerations of crystals, as the individual crystalline form is immersed in the larger mass form.
They are forms that have their advantages as well, and allow the mineral compound to be determined. Mica, for example, often appears in the form of iron ore with flat crusty chips. Branches of sofas, ferns. .
As for the method of refraction of individual metal compounds. It has another feature when the refraction is irregular. It is called rupture. Some mineral compounds are ruptured, and there are mineral compounds in a very distinctive way, such as the curved surfaces of the shag - other black volcanic glass that often displays cracks. to arise.

As for the optical advantages of metallic compounds, they include transparency, color, and luster.

The photographer usually has the greatest dilemma, since this is an advantage of principally the way the surface of a mineral composite reflects light—and descriptions such as metallic, resinous, oily, silky, and pearly luster are very easy to understand, as well as to be seen when a specimen is turned over in the palm to change the play of light on it, and to make the nuances evident in the Photograph We need skillful static lighting.
As for the rocks, they form an accumulation of mineral compounds with much greater variation. There are three types of rocks: volcanic formed from direct melted lava, sedimentary formed from water or other particles carried by the wind, and extrusive formed from a change affecting existing rocks under conditions of temperature and pressure. The important features that need to be highlighted here are the content, structure and structure. The clarity of the rock content depends on the scale of the grains in the individual mineral compounds, and the similarity of these to each other. If we come to granite, we find it showing its content very clearly as long as the granules are not only large and clear, but the three contents in it - quartz - are distinctly different. The surface structure of the rock can also be very distinctive, from the delicate smoothness of marble to the coarseness of lime stone. As for the structure, on the other hand, it often depends on a scale that is much larger than what can be seen in a small sample, although some rocks such as colloidal lava. It shows obvious structural advantages.

lighting

The same general lighting conditions apply to mineral compounds and rocks as they apply to shells and fossils, and many of the same methods can be used. Knowing the intrinsic characteristics of a particular sample will help to decide on the lighting approach. If it is for the boat

Metallic has an interesting luster, for example, like the oily, waxy appearance of chalcedony, then well-dispersed light will reveal it with maximum clarity.
On the other hand, we find that the illumination itself will do nothing to reveal the compact powdery structure of the loess. It is silt deposited by the wind that will appear better with strong direct light, while low-angle light reveals surface interpretations with maximum clarity, but if the structure is of no importance in a sample, more confrontational lighting can be used.

Crystals are probably the most difficult mineral compounds to photograph, since there are many reflections and light cracks to contend with.
The standard approach in general is to show as many surfaces as possible while leaving the overall appearance simple. The best way to achieve this is to make the lighting vary on each surface. We have to capture the reflections of a large light source that is dispersed in at least two main surfaces, and when photographing transparent crystals in particular. This, and it is possible to work carefully on placing reflectors with different strengths on aluminum foil or white cardboard to give different strengths of reflection in each surface.