Digital photography

Digital camera.

Digital photography consists of obtaining images using a camera obscura, similar to analog photography. However, just as in the latter the images are recorded on a photosensitive film and are later revealed by a chemical process, in digital photography the images are captured by an image sensor that has multiple photosensitive units, which take advantage of the effect photoelectric to convert light into an electrical signal, which is digitized and stored in a memory.

Advantages

The advantage of this system compared to chemical photography is that it allows you to have the recorded images instantly, without the need to take the film to the laboratory and develop the negatives to be able to see the images; This advantage in the rapidity in the availability of the image allows the photographer to make the changes at the moment and make the corrections that he considers pertinent immediately, thus making it easier to achieve the desired image.

On the digital camera, you can see the photos you just took on one screen. The camera can be connected to a computer or other device capable of displaying photos on a monitor. As they are in a digital format, the photos can be sent directly by email, posted on the web, and can be processed with photo editing programs on a computer, to enlarge or reduce them, crop (a part of the photo), rectify colors and brightness, and make many other possible modifications depending on the program used.

Another great advantage of digital photography is that each time the camera takes a photo it creates an exif metadata file (non-visual data) and saves relevant information about the capture such as date, time, etc. within the image file. aperture, shutter speed, ISO speed. This information is very useful to study the images and understand more about each photograph and also facilitates the ordering and management of photographic files.

Other useful resources in digital photography are the brightness histogram, which is a graph that shows the distribution of image pixels according to their brightness levels; as well as the RGB histogram that shows the distribution of the pixels in the different color channels: in the case of RGB mode, they will be the channels of red (R: red), Green (G: green), and Blue (B: blue). This resource does not exist in chemical photography.

Transformations in the creation of digital photographs

Professional digital cameras have the option of customizing for different types of user, allowing adjustment of important image characteristics such as saturation, contrast, sharpness, and color tone. They also allow personalized management of the white balance, which can significantly vary the color range and also allow you to capture images in black and white, sepia, with filters, etc. The easy and fast control of the ISO sensitivity helps to solve the problems of lack or excess of light.

Hoja de vid. Image source in IG - kllnt.95

Digital cameras, on the other hand, favor a greater production of photographs, while the limit of the cost and the number of frames of the films disappears, being reduced to the little known data of the useful life of the digital shutter.

Transformations in the circulation and reception of digital photographs

The cost per printed photograph -compared to the chemical system- is lower; this considering that multiple shots can be taken, and choose only desired photographs for printing.

Technological convergence has brought digital cameras to mobile phones and other devices such as tablets, increasing the number of photography users exponentially and each time new models improve optical quality and image resolution, this has caused the photographer's task to be rethought and restructured. Digital photography has created a revolution in the photographic medium. Images are viewed more and more on screens than on paper.

In 2010, there are already millions of users who share their images through social networks such as Facebook and other specialized websites such as Flickr or Picasa, which allow them to store, order, search and share photos online.

Authors such as Fred Richtin, Joan Fontcuberta, or Pedro Meyer have analyzed these phenomena within the framework of what has been called "post-photography". These authors point out that the ease of access of digital photography and the abundance of images are diluting the traditional role of the photographer, the social function of photography and privacy barriers, among other aspects.

Disadvantages

Resolution

The resolution of a 35mm film is around 320 pixels per millimeter, being approximately 87 megapixels. In contrast, expert photographers say that a good chemical film camera, with a high resolution lens, a high resolution film quality and good development would be equivalent to about 40 megapixels. However, in most cases, photography on 35mm film—especially with low-cost film—doesn't exceed 6,000,000 dots, due to the type of camera and inexperience of the person photographing. On the other hand, with a relatively high-quality digital camera and an inexperienced person, better resolution images can be obtained than with its chemical counterpart. Today (2011) some digital cameras have reached 45 megapixels in the 35mm format, as is the case with the Sigma SD1 camera.

Noise

Digital cameras with full frame sensors have a better noise figure than chemical film, especially at low ISO sensitivities. On the other hand, and as a somewhat more subjective view, some photographers consider that the grain of the 35mm film is more pleasant to the eye than the noise of the digital camera; the grain is always —or almost always— monochromatic, while the noise is expressed in colored dots, which interrupt the uniformity of the image.

Due to the heating of the electronic device by the continuous flow of current, the sensor adds noise to the images when these are obtained through a long exposure; in professional systems, this is generally corrected by using a Peltier cell, which keeps the device at a low temperature, thus avoiding the appearance of thermal noise, and in some cases (astronomical photography) the use of very low-temperature liquids is frequent for sensor cooling (liquid nitrogen and hydrogen); another that is known as exposure stacking or exposure stacking, which superimposes several images taken during the general capture time to subtract the noise pattern of the final image.

Abejorro. Image source in IG - kllnt.95

Price

Another disadvantage of digital cameras is their higher cost, compared to conventional cameras, although day by day this gap is narrowing.

One disadvantage of DSLR (digital single-lens reflex) cameras is that they are more delicate than film SLRs, as the sensor that digitizes the image is very fragile and can be easily scratched or damaged; In addition, this tends to get dirty frequently during the change of objectives, in such a way that a delicate cleaning process is necessary periodically. In the case of the chemical film, the possibility of the appearance of dust is diminished due to the fact that the sensitive surface is continuously changed, displacing any possible trace of dirt.

Sometimes digital cameras take a long time while saving file information to the memory card and the BUSY announcement appears, preventing new pictures from being taken until the recording is complete. process the information, this is annoying because some images cannot be captured and escape while this archiving process occurs, this does not happen in chemical photography where the drive motor is in charge of moving the film and leaving the camera ready for the next take.

Achieving a multiple exposure effect is easier in chemical photography than in digital.

Types of cameras

As in classic photography, there are many different types of digital cameras, whether pocket-sized, medium-sized, or for advanced or professional use, with more or less complete optics, and with more or less sophisticated systems. A peculiar characteristic of digital cameras, however, is the resolution. Also in classical photography we talk about resolution, but in this case it depends on the type of film used, since it is the size of the photosensitive grains and the physical dimension of the film that determines the resolution independently of the camera. There is also talk of "magnificent resolution", but only that of the sensor should be taken into account, since interpolation consists of a process that enlarges the image without gaining quality (it can even lose it slightly), since that it always starts from the resolution of the sensor and this is interpolated with mathematical procedures in which it is impossible to obtain the details that the sensor did not capture.

Compact Digital Cameras

They are characterized by being very easy to use, quite small in size (most similar to a cell phone) and simplified operation; this design limits the creative capabilities of capturing images, limiting itself to amateur use. Due to the optical and electronic characteristics (small sensor, low-light objectives), they almost always have a fairly wide depth of field. This allows multiple objects to be in focus at the same time, which makes it easier to use, but it's also one of the reasons advanced photographers find images taken by these cameras flat or artificial. These cameras are ideal for taking landscapes and occasional use. They often save image files in JPEG format, have limited dynamic range, and many apply noise reduction to images, even at the lowest sensitivity available.

Advanced Compact (or Long Zoom) Cameras

These cameras allow greater control of the shots and have more quality and features than the previous ones. Physically, they are larger, with more knobs and buttons, and a larger grip, thus resembling SLR cameras, and sharing some of their features. They generally have long optical zoom (hence their name) which ensures greater creative capacity. They are sometimes marketed as and confused with digital SLR (dSLR) cameras since the camera bodies resemble each other. On some models, screw-in converters can be added to improve range or angle coverage, can take video, record audio, and scene composition takes place on the LCD screen or in an electronic viewfinder. The response speed of these cameras tends to be slower than a true digital SLR, but they can achieve very good image quality while being lighter and more compact. Many of these cameras save photos in JPEG format and there are more and more that can do so in RAW format.

DSLR cameras

DSLRs are the equivalent of chemical film cameras. They are intended for the photojournalism industry, fine art photography, and other advanced/professional uses, because their response characteristics and image quality are generally superior to those of compact cameras. Compared to compact cameras, they have a larger sensor, which is equivalent to a higher signal/noise ratio that translates into better image quality. The design of the electronic components is optimized to provide a response time similar to that of traditional SLR cameras. They have the ability to record in higher quality formats (low compression JPEG, RAW), which is useful in image post-processing. Commercially they are divided by sectors: amateur (few controls, automatic assisted functions, small size), advanced amateur (greater capture customization, additional accessories) and professional (high shooting speed and response, high ISO performance, full frame sensor).

Features

The resolution in digital photography is measured by multiplying the height by the width of the photographs that the camera allows to obtain and generally starts with one million pixels, for the cheapest cameras, and increases to more than ten million pixels, for professional cameras. The term "pixel" (from English picture element), is the smallest unit that captures a gray or color value of the photograph. A camera with four million pixels will generate larger images than one with two million, allowing a print of up to 50 × 75 cm to be obtained, but not necessarily of higher quality since the quality of the image is more important in this regard. optics used. However, since cameras are more expensive at more megapixels, it is common for them to also have better lenses.

Another feature of digital photography is the digital zoom. Using this zoom you can enlarge a photo, but the effect is not that of an optical zoom. The optical zoom zooms in and enlarges what you want to photograph without reducing the resolution of the camera, since the approach is achieved with the lens. Digital zoom, by contrast, enlarges the image you've already received, thereby lowering the resolution, just as you would by ordering an enlargement from the lab or using a graphics editing program.

Currently, digital cameras also allow you to take videos, generally in resolutions from 320×240 to 1920×1080 pixels and between 12 and 60 frames per second, sometimes with sound (usually monophonic) in the case of the most complete models. These videos are reaching such a high level of quality that many professionals are using SLR cameras instead of video cameras.

History

In 1975, the Kodak company commissioned engineer Steve Sasson to develop a prototype camera that did not use film but an electronic sensor. Between the 1960s and 1970s, the electronics industry had produced the first CCDs, sensors that could record a small monochrome image, so Sasson took a CCD, a lens, and an electronic circuit in which he programmed the conversion of electrical values that output to the sensor in digital values. With these three elements, he was able to develop a prototype digital camera whose design was patented by Kodak in 1978. Kodak commercialized this technology in 1991, the year in which its Digital Camera System (DCS) combined a Kodak sensor of 1.3 megapixel with a Nikon F3 camera body. The proposal was to have a camera that could create files to be printed in newspapers and magazines, at that time there were no digital printing services, nor the Internet! The camera had a separate unit connected by a cable, in which the photo taken could be viewed and archived. At the same time, in the graphic industry for the production of books, magazines and printed matter, more and more digital processes were incorporated, which gave rise to the gradual use of graphic design and photographic retouching programs such as Adobe Photoshop. In 1999 the Nikon D1 appeared, the first digital SLR developed entirely by Nikon, with 2.7 megapixels and in 2003 the Canon 300D entered the market, with 6.3 megapixels, the first affordable digital SLR for intermediate users. By 2003 most SLR camera manufacturers had a digital model available. In 1998 Fuji developed the first Digital Minilab, the Fuji Frontier, which allows copies to be obtained on photographic paper from digital photographs, by using a laser that prints the image from the file on the photosensitive paper. Towards the year 2000 the massive use of the Internet began and in 2008 the social networks that included photographs exploded with the appearance of Facebook.

Throughout the history of photography, more than 3,700 digital cameras of different brands have been marketed. (smartphone) that began to conquer ground over the traditional digital camera.