All surfaces are reflective. Some more, some less.
If you shoot a photo of any object before a flat wall, the wall is illuminated
You get a flash back / bright spot in the center of the photo.
Say I photo people or an object before a wall. If the wall is mat or dark in color, I get some flash back from the wall, particularly in the center of my photo, but not to bright. If the wall is a mirror (or glass) I get a very bright flash back or actually a mirror images of the flash itself in the photo.
So all surfaces are reflective, some more or less.
Light moves like a pool ball or billiard ball. When it goes straight in, it bounces straight back.
When it goes in at an angle, it bounces back at the reflected angle.
When you shine a light or flash at an angle, then the reflected light bounces off in the other direction.
So to shoot glass objects, or any thing shiny, bring light in at an angle.
Light or a flash can come directly from the camera, or from a different source;
day light, window light, lamp or separate lighting.
If your only light is on the flash twist your reflective object so the primary surfaces are not perpendicular to the camera lens to avoid most flash back.
If you are photographing against any wall, dark is best, reflects little light.
Light wall reflects more back. Distant back grounds reflect less then near back grounds.
Plain dark back ground will make the primary thing in the photos to be brighter and more visually dominant.
Shoot at an angle to the wall or the primary shiny surfaces.
Most of the light will bounce off in another direction, little flash back.
Better not to use a flash on shiny walls, or glass reflective objects.
Use an external light, flash, lamp, daylight so light come to the object at an angle, not perpendicular to the camera lens.
If the light comes in from the side, it will bounce off to the other side.
Then you can clearly see the edges, surfaces, subject of your photo, like a glass object or other reflective item, .
Photos are but renderings of light. Glass objects or walls reflect light depending on the angle of incident, the angle the light hits them, it bounces off in complimentary angle (like a pool ball shot reflected off the edge of pool table.).
I have an on board (attached) flash, but I can rotate the flash angle, so I can bounce the light off the ceiling or a side wall. Then I don’t get flash back seen in the lens and in the photos.
If you bounce light or a flash, be careful of the surface color you bounce from.
If you bounce from a pink wall, it will color the image with the pink color.
White or beige may be best as a flash bounce surface so as not to color the object of your photo.
Trial and error is the way to learn.
Learn in advance before you have a particular problem. You do not usually learn everything in one trail.
Digital photos give instant results, so you can see what you are doing. (easier to learn) If you work in film, you should write down in advance what different ways you will light, so when you get the photos back, you can see what the different methods rendered in your final images.
Ted Elden, photographer 304 344 2335 email@example.com www.abodia.com
. . . . . . . . . . . . . . . . . . . . . . . . . . .
from Ted Elden - PhotographerTedElden@SuddenLink.net, tel 304 344 2335