Simon Trussell Photography

Simon Trussell
Exposure control

The size of the aperture and the brightness of the scene controls the amount of light that enters the camera during a period of time, and the shutter controls the length of time that the light hits the recording surface. Equivalent exposures can be made with a larger aperture and a faster shutter speed or a corresponding smaller aperture and with the shutter speed slowed down.

There are many ongoing questions about different aspects of photography. In her writing "On Photography" (1977), Susan Sontag discusses concerns about the objectivity of photography. This is a highly debated subject within the photographic community. Photographers decide what to take a photo of, what elements to exclude and what angle to frame the photo. Along with the context that a photograph is received in, photography is definitely a subjective form.

Modern photography has raised a number of concerns on its impact on society. In Alfred Hitchcock's Rear Window (1954), the camera is presented as a promoter of voyeuristic inhibitions. 'Although the camera is an observation station, the act of photographing is more than passive observing'.

The Pentax K-x sits in the slot previously occupied by the company's K200D - one of the best-specified entry-level DSLRs on the market in its time - though that position has now been elevated by the arrival of a new breed of simplified models below it. In Pentax's line-up that means the K2000/K-m designed to entice compact camera users into DSLR ownership with its easy-to-use interface and diminutive scale, and it's that camera the K-x is immediately reminiscent of (they share the same body).

Despite its compact size and use of AA batteries, there is more than a hint of the K-7 about the new model's specifications. It gains the K-7's 11-point AF system and PRIME II imaging engine, along with its abilities to correct for chromatic aberration and distortion when using Pentax DA and DFA lenses. It also features an orientation sensor.

While, unlike the K-m, on the K-x you can now at least select the active AF-point, it's still not displayed in the viewfinder. However, despite of all the shared features with the K2000/K-m and K-7 there is still plenty new about the K-x.

The camera is based around a 12.4 megapixel CMOS sensor with onboard A/D conversion (a system often associated with Sony), with output fast enough not only for the camera to shoot at 4.7 frames per second, but also for capturing 24 frames of 720p HD video per second. Along with the sensor come higher ISOs - now up to 6400, expandable to 12800. Plus there's a revised version of the K-m's shutter mechanism to allow the high continuous shooting speed, which ups the maximum shutter speed to 1/6000 sec. The camera also features a new 'cross-processing' mode on top of an already impressive range of filters and processing options.
Pentax K-x Key Features

* 12.4 megapixel APS-C-format CMOS sensor (total pixels: 12.9 million)
* PRIME II imaging engine
* 1/6000th maximum shutter speed
* 720p HD video (24 fps)
* 2.7" LCD monitor (230,000 dots)
* Image sensor cleaning (sensor shake)
* 11 selectable AF points
* IS0 200-6400 range (100-12,800 when expanded)
* 4.7 frames per second continuous shooting (for 17 frames)

Color photography was explored beginning in the mid 1800s. Early experiments in color could not fix the photograph and prevent the color from fading. The first permanent color photo was taken in 1861 by the physicist James Clerk Maxwell.

According to a survey made by Kodak in 2007, 75 percent of professional photographers say they will continue to use film, even though some embrace digital.

According to the U.S. survey results, more than two-thirds (68 percent) of professional photographers prefer the results of film to those of digital for certain applications including:

* film’s superiority in capturing more information on medium and large format films (48 percent);
* creating a traditional photographic look (48 percent);
* capturing shadow and highlighting details (45 percent);
* the wide exposure latitude of film (42 percent); and
* archival storage (38 percent)

Digital imaging has raised many ethical concerns because of the ease of manipulating digital photographs in post processing. Many photojournalists have declared they will not crop their pictures, or are forbidden from combining elements of multiple photos to make "illustrations," passing them as real photographs. Today's technology has made picture editing relatively simple for even the novice photographer. However, recent changes of in-camera processing allows digital fingerprinting of RAW photos to verify against tampering of digital photos for forensics use.

Camera phones, combined with sites like Flickr, have led to a new kind of social photography.