A camera meter often tries to turn a mostly black subject into middle grey. Increasing exposure reveals noise, dust, and the background while sacrificing the deep tone that made the specimen distinctive. The better approach is to design the reflection before adjusting brightness.
Place the specimen on a quiet, matte surface. Use one broad light source—a window with indirect light or a lamp shining through white fabric—and turn off competing lights. Move a white card around the specimen until a narrow reflection describes the edge or curved fracture surface.
Build the photograph in layers
- Set the camera and specimen so neither moves.
- Choose a background that separates the outline without creating glare.
- Move the broad light until one surface becomes legible.
- Add a small white card for an edge reflection if needed.
- Reduce exposure until the body remains convincingly dark.
- Make a second frame with a scale card if the image is a record.
A polarizing filter can suppress reflections, but complete suppression is rarely the goal with glass. Reflection is part of the evidence for luster and surface shape. The useful photograph controls glare rather than erasing it.
Record versus portrait
A specimen portrait may favor strong light and selective focus. A reference photograph should also show scale, multiple faces, and a neutral color target. Keep those purposes separate. One dramatic image is not a substitute for a plain documentary frame.
Clean the surface with air or a soft brush rather than aggressive polishing. Dust is distracting, but minor marks and weathering may belong to the specimen’s history. Editing should correct exposure and color, not manufacture structures that were not present.