sensor photos on Flickr

These recently uploaded Kodachrome pictures have no artistic value. They were just uploaded to be representative of consumer Kodachrome picture recording during about 70 of the 75 years that Kodachrome was commercially available to the public. Unlike in today’s digital world it took time, money and effort to make a Kodachrome slide. We took fewer pictures, trying to stretch resources, but some are still frivolous.

I'm 97 (2016). I'm about at the end of my ability to continue posting.. The ratio of today’s digital pictures that are kept for any length of time and/or printed is much less than the film photos taken in days past. History will be lost. Meanwhile you get to be bored by some old Kodachromes, Anscochromes, a Dufaycolor and perhaps an old black&white or so.

The Camera: Kodak Retina Reflex ca. 1957?

This picture was taken with a rebuilt Kodak Retina Reflex circa 1957. It had the better six-element (3+3 elements in 4 groups) Schneider-Kreuznach Retina-Xenon C 50mm f/2 lens. This photo was taken in between 2007 and 2010. The lens could out resolve the Kodachrome used. The latest batches of Kodachrome 25 and 64 were rated by the ever truthful Kodak as being equal. Test rolls shot of the same scene in the same light minutes apart with the same clear sky and a Zeiss 50mm F:1.4 on a Contax RX did not look the same under a 60x microscope. The 25 was far superior. Perhaps Joe Isuzu is now Joe Kodak. I must be REALLY old because I can remember when the “branding” of Kodak meant quality consumer products. Today?????

The Film: Kodak Kodachrome 64

Kodachrome was my favorite film. My first roll in the late 30s was such a marvel to a young man. I had tried Dufaycolor which did pretty good, but if it had to be projected you had to ignore the lines of color which made up the image. Kodachrome was so much more colorful to boot. It was extremely sharp and almost grainless compared to other color and B&W processes.

Kodachrome was unique in American film history. Except for a licensee who used Kodachrome’s older process for a few years, nobody made anything like it. Most color films had all the color in the film. Kodachrome picked up color from the processing baths. Also unlike modern slide films which use chemical energy to reverse the negative image, Kodachrome used filtered lights to re-expose within the processing machine. Kodachrome evolved over the years, and was usually the clearest, sharpest grain free color film one could buy. That is until Kodak made a decision to reduce the budget to improve the product in favor of other products and offerings. Fuji Velvia soon eclipsed it in resolution and could be processed locally in regular E-6 mini-machines.

Kodak claimed that their Kodachrome ISO 64 would resolve as much detail as their ISO 25. My results did not bear that out. Had I taken this photo with the ISO 25 instead, the small letters on the sign would be clear and crisp, even with the camera hand held by an old man.

The Scanner, a Nikon 5000:

The Nikon 5000 was rated by the manufacture to scan at 4000 PPI. Unlike most other scanners testing with a glass plate USAF 1951 with the resolution chart metal deposited on it, showed both vertical and horizontal resolution to be very close to that figure. When scanning a chart at maximum resolution one has to be concerned with registration between the lines on the chart and the pixel placement of the sensor. Exact registration is a hit and miss, re-trial exercise. With film the scanned bits of silver and dye clumps are randomly scattered without the need to have perfect alignment. I’d rate the 5000 at or very near 4000 PPI on film. Most scanners are over rated by 50-100%

Sensors by Víctor Castells

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Agfa Silette LK Sensor by Jörg Krüger

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Agfa Silette LK Sensor, introduced 1970, perhaps one of the last Silettes and an early Agfa with the red shutter release button. The body is based on the Agfa Optima 200 from 1968.

It is a low-budget camera, the lens barrel and the housing are made of plastic, though the top and the bottom look like metal. This camera hasn't a rewind crank, the rewinding is done by the advance lever, when the button "R" is tripped before, so the inner mechanism is complex.

The lens is a Color-Agnar 2.8/45 mm with three elements, the shutter is a Parator with 1/30 to 1/300 s and B. The Selenium exposure meter is coupled and the match needle is displayed in the viewfinder and on top, the ASA range is from 25 to 400 ASA. All settings has to be done manually, like on all Silettes, I think. The LK has a thread for a cable release on the backside and a hot shoe. There is no self-timer, no focussing aid and the frame counter has to be reset manually.

(If you want to remove the top plate: there is a third screw hidden in the hot shoe. The cover in the hot shoe has the most diabolic clip mechanism I've ever experienced.)

SENSOR:DISRUPT 2022 by Silicon Saxony e. V.

28. September 2022 | Carlowitzcenter Chemnitz

Sensor Support Structure by Simplified Building

Find out more about this senor suppor at: www.simplifiedbuilding.com/blog/sensor-support-structure/

Sensor by Durley Beachbum

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Our Daily Challenge 31 December -6 January : Slot

My chimney sweep is also a fireman and persuaded me to get this!

St Peter's church Guestwick Norfolk by David

HDR. AEB +/-3 total of 7 exposures processed with Photomatix.

High-dynamic-range imaging (HDRI) is a high dynamic range (HDR) technique used in imaging and photography to reproduce a greater dynamic range of luminosity than is possible with standard digital imaging or photographic techniques. The aim is to present a similar range of luminance to that experienced through the human visual system. The human eye, through adaptation of the iris and other methods, adjusts constantly to adapt to a broad range of luminance present in the environment. The brain continuously interprets this information so that a viewer can see in a wide range of light conditions.

HDR images can represent a greater range of luminance levels than can be achieved using more 'traditional' methods, such as many real-world scenes containing very bright, direct sunlight to extreme shade, or very faint nebulae. This is often achieved by capturing and then combining several different, narrower range, exposures of the same subject matter. Non-HDR cameras take photographs with a limited exposure range, referred to as LDR, resulting in the loss of detail in highlights or shadows.

The two primary types of HDR images are computer renderings and images resulting from merging multiple low-dynamic-range (LDR) or standard-dynamic-range (SDR) photographs. HDR images can also be acquired using special image sensors, such as an oversampled binary image sensor.

Due to the limitations of printing and display contrast, the extended luminosity range of an HDR image has to be compressed to be made visible. The method of rendering an HDR image to a standard monitor or printing device is called tone mapping. This method reduces the overall contrast of an HDR image to facilitate display on devices or printouts with lower dynamic range, and can be applied to produce images with preserved local contrast (or exaggerated for artistic effect).

In photography, dynamic range is measured in exposure value (EV) differences (known as stops). An increase of one EV, or 'one stop', represents a doubling of the amount of light. Conversely, a decrease of one EV represents a halving of the amount of light. Therefore, revealing detail in the darkest of shadows requires high exposures, while preserving detail in very bright situations requires very low exposures. Most cameras cannot provide this range of exposure values within a single exposure, due to their low dynamic range. High-dynamic-range photographs are generally achieved by capturing multiple standard-exposure images, often using exposure bracketing, and then later merging them into a single HDR image, usually within a photo manipulation program). Digital images are often encoded in a camera's raw image format, because 8-bit JPEG encoding does not offer a wide enough range of values to allow fine transitions (and regarding HDR, later introduces undesirable effects due to lossy compression).

Any camera that allows manual exposure control can make images for HDR work, although one equipped with auto exposure bracketing (AEB) is far better suited. Images from film cameras are less suitable as they often must first be digitized, so that they can later be processed using software HDR methods.

In most imaging devices, the degree of exposure to light applied to the active element (be it film or CCD) can be altered in one of two ways: by either increasing/decreasing the size of the aperture or by increasing/decreasing the time of each exposure. Exposure variation in an HDR set is only done by altering the exposure time and not the aperture size; this is because altering the aperture size also affects the depth of field and so the resultant multiple images would be quite different, preventing their final combination into a single HDR image.

An important limitation for HDR photography is that any movement between successive images will impede or prevent success in combining them afterwards. Also, as one must create several images (often three or five and sometimes more) to obtain the desired luminance range, such a full 'set' of images takes extra time. HDR photographers have developed calculation methods and techniques to partially overcome these problems, but the use of a sturdy tripod is, at least, advised.

Some cameras have an auto exposure bracketing (AEB) feature with a far greater dynamic range than others, from the 3 EV of the Canon EOS 40D, to the 18 EV of the Canon EOS-1D Mark II. As the popularity of this imaging method grows, several camera manufactures are now offering built-in HDR features. For example, the Pentax K-7 DSLR has an HDR mode that captures an HDR image and outputs (only) a tone mapped JPEG file. The Canon PowerShot G12, Canon PowerShot S95 and Canon PowerShot S100 offer similar features in a smaller format.. Nikon's approach is called 'Active D-Lighting' which applies exposure compensation and tone mapping to the image as it comes from the sensor, with the accent being on retaing a realistic effect . Some smartphones provide HDR modes, and most mobile platforms have apps that provide HDR picture taking.

Camera characteristics such as gamma curves, sensor resolution, noise, photometric calibration and color calibration affect resulting high-dynamic-range images.

Color film negatives and slides consist of multiple film layers that respond to light differently. As a consequence, transparent originals (especially positive slides) feature a very high dynamic range

Tone mapping

Tone mapping reduces the dynamic range, or contrast ratio, of an entire image while retaining localized contrast. Although it is a distinct operation, tone mapping is often applied to HDRI files by the same software package.

Several software applications are available on the PC, Mac and Linux platforms for producing HDR files and tone mapped images. Notable titles include

Adobe Photoshop

Aurora HDR

Dynamic Photo HDR

HDR Efex Pro

HDR PhotoStudio

Luminance HDR

MagicRaw

Oloneo PhotoEngine

Photomatix Pro

PTGui

Information stored in high-dynamic-range images typically corresponds to the physical values of luminance or radiance that can be observed in the real world. This is different from traditional digital images, which represent colors as they should appear on a monitor or a paper print. Therefore, HDR image formats are often called scene-referred, in contrast to traditional digital images, which are device-referred or output-referred. Furthermore, traditional images are usually encoded for the human visual system (maximizing the visual information stored in the fixed number of bits), which is usually called gamma encoding or gamma correction. The values stored for HDR images are often gamma compressed (power law) or logarithmically encoded, or floating-point linear values, since fixed-point linear encodings are increasingly inefficient over higher dynamic ranges.

HDR images often don't use fixed ranges per color channel—other than traditional images—to represent many more colors over a much wider dynamic range. For that purpose, they don't use integer values to represent the single color channels (e.g., 0-255 in an 8 bit per pixel interval for red, green and blue) but instead use a floating point representation. Common are 16-bit (half precision) or 32-bit floating point numbers to represent HDR pixels. However, when the appropriate transfer function is used, HDR pixels for some applications can be represented with a color depth that has as few as 10–12 bits for luminance and 8 bits for chrominance without introducing any visible quantization artifacts.

History of HDR photography

The idea of using several exposures to adequately reproduce a too-extreme range of luminance was pioneered as early as the 1850s by Gustave Le Gray to render seascapes showing both the sky and the sea. Such rendering was impossible at the time using standard methods, as the luminosity range was too extreme. Le Gray used one negative for the sky, and another one with a longer exposure for the sea, and combined the two into one picture in positive.

Mid 20th century

Manual tone mapping was accomplished by dodging and burning – selectively increasing or decreasing the exposure of regions of the photograph to yield better tonality reproduction. This was effective because the dynamic range of the negative is significantly higher than would be available on the finished positive paper print when that is exposed via the negative in a uniform manner. An excellent example is the photograph Schweitzer at the Lamp by W. Eugene Smith, from his 1954 photo essay A Man of Mercy on Dr. Albert Schweitzer and his humanitarian work in French Equatorial Africa. The image took 5 days to reproduce the tonal range of the scene, which ranges from a bright lamp (relative to the scene) to a dark shadow.

Ansel Adams elevated dodging and burning to an art form. Many of his famous prints were manipulated in the darkroom with these two methods. Adams wrote a comprehensive book on producing prints called The Print, which prominently features dodging and burning, in the context of his Zone System.

With the advent of color photography, tone mapping in the darkroom was no longer possible due to the specific timing needed during the developing process of color film. Photographers looked to film manufacturers to design new film stocks with improved response, or continued to shoot in black and white to use tone mapping methods.

Color film capable of directly recording high-dynamic-range images was developed by Charles Wyckoff and EG&G "in the course of a contract with the Department of the Air Force". This XR film had three emulsion layers, an upper layer having an ASA speed rating of 400, a middle layer with an intermediate rating, and a lower layer with an ASA rating of 0.004. The film was processed in a manner similar to color films, and each layer produced a different color. The dynamic range of this extended range film has been estimated as 1:108. It has been used to photograph nuclear explosions, for astronomical photography, for spectrographic research, and for medical imaging. Wyckoff's detailed pictures of nuclear explosions appeared on the cover of Life magazine in the mid-1950s.

Late 20th century

Georges Cornuéjols and licensees of his patents (Brdi, Hymatom) introduced the principle of HDR video image, in 1986, by interposing a matricial LCD screen in front of the camera's image sensor, increasing the sensors dynamic by five stops. The concept of neighborhood tone mapping was applied to video cameras by a group from the Technion in Israel led by Dr. Oliver Hilsenrath and Prof. Y.Y.Zeevi who filed for a patent on this concept in 1988.

In February and April 1990, Georges Cornuéjols introduced the first real-time HDR camera that combined two images captured by a sensor3435 or simultaneously3637 by two sensors of the camera. This process is known as bracketing used for a video stream.

In 1991, the first commercial video camera was introduced that performed real-time capturing of multiple images with different exposures, and producing an HDR video image, by Hymatom, licensee of Georges Cornuéjols.

Also in 1991, Georges Cornuéjols introduced the HDR+ image principle by non-linear accumulation of images to increase the sensitivity of the camera: for low-light environments, several successive images are accumulated, thus increasing the signal to noise ratio.

In 1993, another commercial medical camera producing an HDR video image, by the Technion.

Modern HDR imaging uses a completely different approach, based on making a high-dynamic-range luminance or light map using only global image operations (across the entire image), and then tone mapping the result. Global HDR was first introduced in 19931 resulting in a mathematical theory of differently exposed pictures of the same subject matter that was published in 1995 by Steve Mann and Rosalind Picard.

On October 28, 1998, Ben Sarao created one of the first nighttime HDR+G (High Dynamic Range + Graphic image)of STS-95 on the launch pad at NASA's Kennedy Space Center. It consisted of four film images of the shuttle at night that were digitally composited with additional digital graphic elements. The image was first exhibited at NASA Headquarters Great Hall, Washington DC in 1999 and then published in Hasselblad Forum, Issue 3 1993, Volume 35 ISSN 0282-5449.

The advent of consumer digital cameras produced a new demand for HDR imaging to improve the light response of digital camera sensors, which had a much smaller dynamic range than film. Steve Mann developed and patented the global-HDR method for producing digital images having extended dynamic range at the MIT Media Laboratory. Mann's method involved a two-step procedure: (1) generate one floating point image array by global-only image operations (operations that affect all pixels identically, without regard to their local neighborhoods); and then (2) convert this image array, using local neighborhood processing (tone-remapping, etc.), into an HDR image. The image array generated by the first step of Mann's process is called a lightspace image, lightspace picture, or radiance map. Another benefit of global-HDR imaging is that it provides access to the intermediate light or radiance map, which has been used for computer vision, and other image processing operations.

21st century

In 2005, Adobe Systems introduced several new features in Photoshop CS2 including Merge to HDR, 32 bit floating point image support, and HDR tone mapping.

On June 30, 2016, Microsoft added support for the digital compositing of HDR images to Windows 10 using the Universal Windows Platform.

HDR sensors

Modern CMOS image sensors can often capture a high dynamic range from a single exposure. The wide dynamic range of the captured image is non-linearly compressed into a smaller dynamic range electronic representation. However, with proper processing, the information from a single exposure can be used to create an HDR image.

Such HDR imaging is used in extreme dynamic range applications like welding or automotive work. Some other cameras designed for use in security applications can automatically provide two or more images for each frame, with changing exposure. For example, a sensor for 30fps video will give out 60fps with the odd frames at a short exposure time and the even frames at a longer exposure time. Some of the sensor may even combine the two images on-chip so that a wider dynamic range without in-pixel compression is directly available to the user for display or processing.

en.wikipedia.org/wiki/High-dynamic-range_imaging

Flexible Sensors by Lawrence Livermore National Laboratory (LLNL)

Lawrence Livermore National Laboratory is developing several microelectromechanical-based sensors, which are fabricated from silicon with techniques similar to those used by the electronics industry. MEMS-based sensors are ideal for use in warheads because of their small dimensions, material properties, low power consumption, and mass manufacturability. Embedded sensors must fit into spaces not originally designed to accommodate them. As a result, they must be extremely thin (about one-half the thickness of a human hair) and be able to bend, flex, and stretch to conform to any curved surface. The flexible array of 900 contact stress sensors shown here can conform to any shape. [More information]

sensores by valdorre

diodos infrarrojos y encoder, partes usadas del mouse

Standout sensor by Sandia Labs

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A version of Sandia National Laboratories’ advanced sensor, called Icarus, is displayed separate from its ultra-high-speed, burst-mode camera. An Albuquerque-based startup plans to make the highly sought tech available to new markets.

Learn more at bit.ly/3yB6UCq

Photo by Craig Fritz

Sensors of Heat by Yudysun Pratama

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PENTAX K10D

TAMRON SP AF 90mmF/2.8 Di MACRO1:1 MODEL 272E

P1460070 MHV77 BV66 VGM at London Bridge Station London Bridge South Side London Bridge London GONEW049 by Anthony Or

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Go-Ahead London Central (MHV77, BV66 VGM, Camberwell/Warner Road (Q)-based) at London Bridge (South Side)/Duke Street Hill, London Bridge, London. Body no NB693, delivered new 13/09/2016. Apologies for the mark on the left hand side of the photo, caused by a clump of sensor dust that got into one of the filters in my camera lens.

Building sensors with Joel by Ben Chun

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Using Arduino to get the cost of probeware down (for science education).

Vernier's cheapest interface is $61 and handles one sensor: www.vernier.com/mbl

Arduino Uno is $30 and has 6 analog inputs: www.sparkfun.com/products/9950

Our goal is to interoperate with this curriculum: www.concord.org/activities/research-focus/probeware

Stroke sensor bracelet by Plusea

Photo Transistor Light Sensor by Adafruit Industries

Available at Adafruit!

SENSOR:DISRUPT 2022 by Silicon Saxony e. V.

28. September 2022 | Carlowitzcenter Chemnitz

St Andrew's church Guist Norfolk by David

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HDR. AEB +/-3 total of 7 exposures processed with Photomatix. Colors adjusted in PSE.