~ Author Unknown

Visible light from the sun travels in a straight line as a wave that is oscillating in all directions, such as up and down, and from side to side. When that light is reflected off an object, it is the reflected wavelength of the light that determines the colour of the object. The rest of the colours are absorbed by the object.

For example, a pure blue-coloured object reflects only blue light and absorbs the red, orange, yellow, green, indigo, and violet parts of the light. Likewise, green leaves on trees only reflect green and some yellow, whilst absorbing the other colours.

If the light being reflected or scattered travels in only one direction – the polarized one – it will cause glaring and reduce the colour intensity of the reflected surface. So, by using a special filter to remove this polarized light, the colour intensity will be restored.

A polarizing filter has a layer of Polaroid sandwiched between two glass plates. In a circular polarizing filter, as the front plate is rotated, the angle of polarization and thus the amount of polarized light that passes through the filter changes. This allows precise control of the degree of polarized light that is to be removed.

Now, when sunlight encounters atoms in the Earth’s atmosphere, which are mostly of nitrogen and oxygen, the light scatters. Blue light is scattered more than red light, which is why a clear sky during the day appears blue in colour.

The electric field of scattered light tends to oscillate in one direction. So, if the photographer is looking perpendicularly to the direction from which the light is travelling, it will be polarized because the energy goes one way.

By applying a Polaroid filter, the energy of the light along one axis can only pass through, hence why the filtering effect works best when the sun is at right angles to the direction the photo is being taken, and the sky will appear to be darker blue in colour.

If the sun is in front or behind the photographer, the polarizing filter will make no difference because the axis of oscillation will not be filtered by the Polaroid, and thus no effect will be seen.

There are two kinds of polarizing filter available to photographers – linear and circular, but only the circular type will work properly with digital cameras. This is because the linear type affects metering accuracy as autofocus cameras already polarize some light inside the camera and a false meter reading will be obtained.

Circular polarizing filters are made with a wave-retardation plate, exactly a quarter of a wavelength in thickness, which lets the light to passing into the metering system appear unpolarized. However, if you do have a linear polarizer, simply take a meter reading before attaching the filter, and then increase exposure time by a couple of stops. That should do the trick. With film cameras it makes no difference which type of filter you use.

All digital SLR cameras have an auto exposure lock button. When you press the AE-L button, the current exposure settings are fixed (locked) so that they can’t change as you recompose the shot – even if the level of light alters as you aim the camera elsewhere.

When the shutter is pressed halfway down, the autofocus mechanism is engaged. As it does so, the camera takes a meter reading and sets the exposure. But what if you want to focus and meter from different parts of the scene?

This is where the auto exposure lock function comes in handy. It lets you take an exposure reading independently of where you want to focus.

The AE-L function is best used with spot or partial metering in order to fix the meter reading from a small area in the scene. This is very useful in lighting conditions that may fool the metering system.

For example, if you shoot a scene that has a bright source in part of the image, an evaluative, matrix or multi-zone meter can easily force underexposure. To get the right exposure, you need to take a reading away from the bright region.

This can be easily be done by taking a spot or partial meter reading from a mid-tone area of the scene and then locking that reading by pressing the AE-L button, and keeping it pressed until you’ve recomposed and taken the shot. On some cameras you don’t need to keep the AE-L button depressed, on others you do.

The AE-L button can be used if the subject or subjects are positioned off-centre in the scene. It is also useful when you are shooting a sequence of images that you want to be stitched together in order to produce a panoramic photograph. The AE-L function makes sure that every shot taken in the sequence has exactly the same exposure settings.

Antique Photo Enlargements

Just because most vintage photographs are not large in size, doesn’t require that you be limited to tiny pieces of wall art. It is quite simple to order enlargements from old photographs if you are fortunate enough to have negatives for them. But, even if you don’t have a negative, a small antique photo can still be transformed into a larger piece of wall art. With a scanner you will be able to turn your small photograph into a large digital photography file. Then you can print that file as a large wall portrait or use a poster printer and create a unique and personal antique print or poster.

Antique Photo Collage

When you have a selection of favorite vintage photos it is the perfect opportunity to create a photo collage. You may choose picture frames which are made for the purpose of displaying numerous photos or you may want to create a custom photo layout using a scanner and printer, and computer graphics software. To begin, select the vintage photographs you would like to utilize. Next, come up with your layout by arranging the photos over and around each other in different ways. Don’t forget to take a snapshot with your camera when you come up with a collage layout that you like best to refer to later. Scan the photos you’ve chosen, making sure to enlarge any that you need to. You may then print the individual photographs, and then arrange them according to your layout plan and attach them to a board for backing. If you have graphics software you can arrange them digitally and then simply print your layout.

Antique Photo Enhancement

Often old photographs get somewhat degraded over time. With computer graphics software you will be able to enhance them. After you’ve scanned a photo, retouching tools may be used to eliminate fold lines and bends and to reconstruct areas that may have become torn through the years. You will be surprised at the improvement this process will have on your vintage photos. The computer graphics software will also give you the ability to adjust colors and produce several different special effects. One such visual enhancement would be to change a scan of an old black and white photograph by adding a lovely old sepia tint. These techniques allow you to enhance your antique photos, without needing to alter or damage the originals.