When light strikes the CCD surface, it frees electrons to move around and those electrons accumulate in capacitors. Those electrons are “counted” at regular intervals by a circuit which dumps the electrons from each point on the CCD surface. When all of these measurements are combined, a picture can be instantly reproduced as a “virtual mosaic” of the individual point measurements. This is the picture we see. The more points of measurement found on the CCD, the higher the “resolution” of the resulting picture.
When building a highly specialized camera, digital technology such as this opens new doors which are not possible with film based technology.
In dentistry, an X-ray machine can be converted to a digital camera with a CCD which is sensitive to the photons that make up the X-ray spectrum. Instead of imprinting an image of X-ray on film, developing the film and finally reviewing the tiny film image, modern X-ray cameras can instantly display an X-ray image on a computer screen as the CCD processes the array of photon measurements. This not only saves time, but also produces no waste in the form of exposed film and development chemicals. So with this frequently used, specialized camera, digital technology creates improvements in a dentist’s practice and protects the environment.
Another specialized camera that benefits from digital technology is the telescope. Traditional cameras, mounted to telescopes collect points of light and expose the film. This can provide more sensitivity than the human eye to faint points of light, but brighter points of light can also obscure fainter ones by “washing out” the image. With the application of digital technology the film camera is replaced by a digital camera using a CCD. The CCD can continue to receive and measure photons indefinitely. This means the process is a continuous measurement in contrast to the more simple exposure of a piece of film. Computers can then electronically filter out brighter sources of light making possible the detection of very faint points of light in the sky and even the study of celestial objects by the detection of the shadows they cast instead of the light they give off. By comparing the light collected over time, digital technology also allows this digital camera to detect distant objects by inferring their presence.
A twenty-four millimeter wide angle lens sees an angle of eighty-four degrees, sufficiently wide for our purposes. A wider angle lens starts to show too much distortion through foreshortening and a less wide lens will make the room seem smaller. A second choice of a twenty-eight millimeter lens with an angle of view of seventy-five degrees is acceptable. A trick I have used to increase the width of view is to shoot through a doorway, just missing the sides of the opening. Unless you own an expensive perspective correcting lens, a distance of four feet from the floor is ideal to prevent convergence (when the walls appear to tilt in). If you own a digital camera with a 28mm lens, perspective can be corrected digitally with software from Adobe Image Ready or the equivalent. Most wide angle lenses share the fault of barrel distortion. This can be corrected with software from radcor.com.
Walk around the room and choose a view that includes the best look for most of the furniture. Two different views may be necessary to tell the whole story. For a spacious look, shoot into a corner, slightly to the right or left of dead center. Pictures taken at right angles to a wall look constricted and less spacious. Interesting table tops will look better from a higher angle. Be sure to light all lamps in the rooom.
Another method of presenting a whole room in one picture is to use the stitch method. First find the center of the lens node. This is a point halfway between the front element and the sensor chip. Place the camera on a tripod, attached at the node point. Level the camera, set the lens on 50mm* (equivalent) and take several slightly overlapping pictures. The images may be stitched manually or helped with software for that purpose. Be sure to smooth any indications of joining.
While flash on the camera is safe and will render the whole scene in accurate color, too much is lost in the way of depth, highlight and shadow detail and in attaining an interesting look. Flash on the camera flattens the scene, reflects unnaturally off flat surfaces and introduces a dark shadow around every object in the room. A better lighting includes a single bright light in a large reflector and a second light bounced off the back wall not appearing in the picture. Items of a dark nature like a dark stained cabinets need an additional spotlight in order to balance the tones in the picture. Night time pictures avoid the problem of overly lit windows, but if the window treatment only looks good with light coming through the window, time your photos at dawn or at dusk. The bluish light entering the window at these times while not matching in color temperature is quite dramatic and attractive. This blue light can be corrected later in the computer.
Fan Heater Not Suitable for Darkroom Heating
In times gone by I used a fan heater which was fine for drying the finished prints hanging on the “clothes line” but created a dust problem with negatives needing to be repeatedly dusted off. Sometimes I’d get hairy strands of dust sticking to the emulsion of negatives while hanging in the darkroom to dry. Eventually I abandoned this method of darkroom heating, the hassle to keep warm being just too much.
Warming the Developer with Hot Water
To warm the developer to a quick acting temperature, I have for some time used a second, larger tray of hot water with the developer tray sitting in it. Whenever the water feels cool to my fingers it’s time to add another jug of hot water, until after a few top-ups, the developer tray starts to float, at which time I tip out the water and start again with more hot water. This method has served me well for 15 years or so and is a good way to go in a low budget darkroom.
Electric Bar Heater for Darkroom Heating
Over recent times I’ve used a bar heater on the darkroom wall. With some care, given the colour and low level of light, the paper has been unaffected by this darkroom heating.
But today I just couldn’t stand the fiddling with jugs of hot water any longer. I unscrewed the bar heater from the wall and placed it on the darkroom floor, facing upwards, under the wet bench, to heat not only the darkroom space but also the chemicals.
I want you to picture yourself and your family outside on a nice afternoon. It’s Thanksgiving, a great day for a family portrait. Unless it is a cloudy day, some nice shade will produce a flattering lighting ratio for your portrait. This means that the brightest part of the picture and the darkest part are not too far apart in value for the film or hard drive card to capture. Then choose a uniform background for you portrait. A stand of dark evergreens, a barn wall, a distant lawn, or a high hedge are all excellent backgrounds. The back of the house and patio, the driveway with the parked cars, or partially sunlit woods are too busy a background for your picture.
Next find something for people to sit on: a log, a small table from the patio, a picnic bench or a patio chair. The object is to have everyone’s head at a different level. Small children are, of course already low to the ground. Seat some people at chair height, others on the ground. Sitting like an Indian is not a viable pose. Try sitting the person down on the ground with their knees together, ankles crossed and to the side. Standing and leaning against something also provides a different height for your composition. Try to place the heads so that they do not line up either vertically or horizontally. Rather than presenting a square shoulder to the camera, a slight turn to the body is preferable. Eye glasses can be held in the hands or tilted down. Be creative in you grouping – two, threes and fours in a close grouping look better than one group of seventeen evenly spaced. Remember to overlap shoulders so that heads are closer together. One shoulder is all that is necessary to see.
Arms should never hang straight down. Instead, place some hands in pockets, around shoulders or holding hands. Diagonals in the composition increase the dynamic qualities of your portrait. Pay attention to the legs and feet. Natural looking positions include crossed ankles, placing the feet forty-five degrees apart (standing), and crossed knees. After the positioning everyone, stand back and squint at the effect with blurred eyes. Turn any straight on bodies and relocate any misplaced color or glaring whites for a more pleasing effect.
A broad, low light source is ideal for a flattering look to your portrait. An open sky overhead will result in dark eye shadowing. Reflecting light into the shadow areas or using fill flash will correct this situation. Take advantage of the light from a white building or a setting sun. A natural solution is to place your group under some overhanging branches.