lighting for taking photos of polished rock

[James]

what type of light can i use that will alow me to take photos of polished
rock. the surface of which is quite reflective.

 

[Daniel J. Stern]

what type of light can i use that will alow me to take photos of polished
rock. the surface of which is quite reflective.

Use a directional light source placed at approximately a 45-degree
angle above the subject matter, and use a rotable linear polarizing filter
on your camera lens, rotated until the reflection of the light source
disappears.

-Stern

 

[Paco Rosso]

what type of light can i use that will alow me to take photos of polished
rock. the surface of which is quite reflective.

I would do this:

First envolve the rock with a white surface, as fabric, clothes ¿How is
in english that white fabric you use to sleep? (in spanish "sábana").
Put the lights on the other side of the fabric, so it work as a diffusor.

Other solution. Put the rock into a white space, by chande a white room,
and set the light to shoot to the walls, never to the rock.

Other, you can use that reflective surfaces used in construction:
porexpan. But remember it reflect a great amount of ultraviolet light,
so you can get a bluish color fominant in the photo.

 

[Stephen H. Westin]

what type of light can i use that will alow me to take photos of polished
rock. the surface of which is quite reflective.

That depends on what you want to do. If you want to eliminate the
reflection entirely, use *two* polarizers: one on the light source and
one on the camera lens. Rotate so that the specular reflection is
cross-polarized and disappears. This will only work completely for a
flat surface, but it will probably help with others. If, on the other
hand, you want to show some reflection but subdue it, maximize the
area of the light source. Shoot inside a white tent, or use a softbox,
umbrella, or other diffuser to give a large, low-intensity light that
will reduce highlight contrast. This is typically done when
photographing cars or glassware.

 

[William H. Hathaway]

That depends on what you want to do. If you want to eliminate the
reflection entirely, use *two* polarizers: one on the light source and
one on the camera lens. Rotate so that the specular reflection is
cross-polarized and disappears. This will only work completely for a
flat surface, but it will probably help with others. If, on the other
hand, you want to show some reflection but subdue it, maximize the
area of the light source. Shoot inside a white tent, or use a softbox,
umbrella, or other diffuser to give a large, low-intensity light that
will reduce highlight contrast. This is typically done when
photographing cars or glassware.

I can see how the polarizers would help with flat surfaces.
The white tent or softbox, etc. seems like it would help with
glassware, which tends to have curved surfaces.

I have the task (for my spare time - gales of laughter) of
photographing a collection (>1000 items) of light bulbs (and
vacuum tubes.) Lighting of light bulbs, with their spherical
and near-spherical reflective envelopes (or a mercury pool
arc rectifier with three or six 'ports') is not a light-duty
endeavor. I need to show the insides clearly without glare -
and probably in separate shots, get images of ID markings on
the glass surfaces or base. Fun.
I got good ideas from a publication ("Old Timer's Bulletin") put
out by the Antique Wireless Association. Spread out light and
white and embrace the blessings of quick feedback from digital
cameras.

My advice - stick with your flat polished rocks.

"If it were easy, it would have been done."
Wm. Hathaway