Educational Content
NOTE: Educational documents here are provided for the betterment of the readers photographic knowledge.
No financial gain is derived from any of the documents provided herine and no copyright infringement is intended by their distribution.
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Taking the "perfect" photo...
« Science is the knowledge of many, orderly and methodically digested and arranged, so as to become attainable by one. »
- John Frederick William Herschel (English Polymath 1642-1726)
This section is designed to teach the reader all they may need to know in order to obtain quality photographic results, no matter the scenario, with very little energy expenditure in thinking about how to achieve the desired exposure.
Important Terminology:
Abberation (Chromatic):
The tendancy for light within a lens to
Abberation (Spherical):
The tendancy for light within a lens to
Aperture:
The size of the opening in the camera lens allowing light to reach the sensor or film. Think of this as controling the volume of light entering the camera, more light requires a faster shutter speed to compensate and keep from making an overexposed image, and vice versa.
NOTE: Adjusting aperture will invariably impact the depth of field in a scene.
Depth of Field:
The region of an image that is in focus, this is represented by an imaginary flat plane perfecdtly parallel with the film or sensor plane. This plane is very narrow when aperture is wide open, and becomes much larger when a smaller aperture is utilized.
NOTE: when using a shallow depth of field obtaining perfect focus on the desired subject is crutial. A larger depth of field provides more leniancy if the object in question is moving or if a landscape is the subject
Dynamic Range:
"The dynamic range (DR) is the ratio between the highest and lowest exposure that can be acquired on the sensing device." A high dynamic range offers a more detailed record of the information in highlights and shadows.
Element:
An individual optical lens within a larger compound lens system.
Front and rear element refering to the front of the lens, and the back of the lens respectiveley.
Focal Length:
The focal length of a given lens is the distance from the rear element to the sensor/film plane when the lens is focused at infinity.
NOTE: Focusing on objects closer than infinity requires moving the lens farther away from the sensor/film. This poses a limitation to some cameras and lenses, such as high zoom lenses and large format cameras, as they need to be prohibitively long to allow for closer focusing. To compensate for this, adapters exist to extend the disance from the rear element to the sensor/film. Additionally larger bellows are sold to allow for similar range in large format cameras.
HDR digital photo:
Using multiple exposures and a tripod, photographs taken using different exposure settings may be merged to create an image with a much higher dynamic range than a camera may be able to produce in a single image. This process is easily handled by photo editing softwares such as Photoshop and GIMP, and can result in vastly improved imagery from what a camera may otherwise be able to obtain.
ISO:
Refers to the sensitivity of a cameras sensor or film to light entering the camera.
NOTE: ISO cannot be changed in a film camera once a roll of film has been started. ISO, from the greek word Isos meaning equal.
Shutter:
The physical barrier that governs the duration of a sensor or films exposure. The speed, size, and shape this opening passes across the film plane impacts the amount of light allowed to reach the camera sensor. Shutters are generally either curtain or leaf, with the latter predominately being used in older cameras and large format photography.
NOTE: fast moving object will expose at different locations as the shutter passes across the sensor or film, this can be seen in the wheels of fast moving cars appearing to flatten and angle in the direction of movement.
Citations
https://corp.dxomark.com/wp-content/uploads/2017/11/2012-Film_vs_Digital_final_copyright.pdf
"Film" Speed
Known as ISO, the speed of a film being utilized will impact the amount of light a camera will need to take in in order to obtain desired exposure levels. Depicted below is a Bayer filter, invented by a Kodak lab tech, used to categorize the entire spectrum of light entering a camera into discrete colors used in processing the otherwise monochrome sensor imagery into a full color RBG photograph. It consists of an array of colored filters and microlenses scattered in a uniform pattern over the camera sensor.
Note: The size of a cameras individual pixels has the greatest impact on the sensitivity of said pixels. Larger pixels are capable of taking in a greater amount of light, and thus result in a less noisy image. Meaning a full frame
P.S. ISO is the name of the International Organization for Standardization (simplified using the Greek Isos, meaning "equal" ie. Isosceles triangle)
Shutter Speed
IR Filtered
ISO: 500
Time: 8 sec
(Infra-Red filtration blocks out upwards of 80-90% of light entering the camera, much like the neutral density filters (ND) one mght use to make a sportsball player drag into a ghostly effect, or take along exposure shot of a waterfall during broad daylight. This means a much higher ISO, or slower shutter speed is necessary to maintain the "exposure triangle" and obtain a proper photo. In this case a combination of both was utilized to keep the exposure from becoming prohibitively long.)
Standard B&W
ISO: 100
Time: 1/60 sec
(This image was taken at the same time as a control to demontrate the necessary changes to ISO and shutter speed that must be made when taking an Infra-Red image. This demontration is still very relevant outside of IR photography.)
No Light Filter
ISO: 400
Time: 1/2500 sec
200mm
F/4.5
Aperture, F/Stops, & Depth of Field
The GIF above helps to demonstrate the effects of changing the aperture of a lens.
(while simultaneously correcting for exposure by changing the shutter speed to compensate for the increase and decrease in light reaching the sensor)
This image (NOT MINE) shows the distinct difference in bokeh (or blurryness) of the background when a lens is stopped far down, on the left, and when it is wide open, on the right.
Note: in order to achieve proper exposure while limiting high ISO enduced grain, a slower shutter speed must be selected for the image on the left half.
Bokeh: The blurred appearance of objects not within the in focus depth of field of a cameras viewed scene. The characteristic shape of these points are determined by the properties of the lens.
Bokeh & Aperture Shape
These images demonstrate the reduction in light entering the camera as the aperture is stopped down to its maximum. Exposure corrected images are also supplied to demonstrate the effective power of post production exposure modification.
NOTE: As the aperture becomes smaller it takes on the shape made by the metal blades that form it. In the case of this lens it is clearly composed of a 6 blade design, given its characteristic hexagonal Bokeh.
f/4.5 (Post Capture Exposure Corrected)
f/4.5
f/5.6 (Post Capture Exposure Corrected)
f/5.6
f/6.7 (Post Capture Exposure Corrected)
f/6.7
f/8 (Post Capture Exposure Corrected)
f/8
f/9.5 (Post Capture Exposure Corrected)
f/9.5
f/11 (Post Capture Exposure Corrected)
f/11
f/16 (Post Capture Exposure Corrected)
f/16
f/22 (Post Capture Exposure Corrected)
f/22
NOTE: Above images are taken of sun glare on a window crack, artifacts to the lower left and uper right of the primary glare are not diffraction spikes.
Depth of Field
As demonstrated in the images above,
when a high aperture is selected (an aperture with a higher f/#) the depth of field is much wider, allowing much more of a scene to be brought into focus.
When a lower aperture is selected (an aperture with a low f/#) the depth of field is much shallower, bringing a much narrower region/plane of a scene into sharp focus
Note: the laws of physics limit the actual sharpness of an image at very high f/#'s, this is known as diffraction limitation and is resultant from the limit posed by the wavelength of light itself as it passes through the aperture. More about this can be read about in the "Diffraction Limitation" section (this can be searched for using the table of contents or the magnifying glass both at the top of the page). With this said, THE SHARPEST IMAGES are obtained using the widest possible aperture even though the region that can be brought into focus will be shallower.
Diffraction Spikes
The long lines radiating from point sources of light, intensified by increasing the aperture, are caused by the interaction of light with the edge of the aperture blades. The wider open the aperture the more circular the blades and the less prominant the optical property, the smaller the aperture blades the more prominant the shape they form. For this reason more expensive lenses will have ever more blades in their apertures to make an ever more perfect circle.
This is a diffraction property of light, the same property by which holograms and lippmann plates operate, see Darkroom Science for more details.
Focal Length
Examle of the compression effects between an 18m lens and a 34mm lens.
Nikkor DX 18mm
These photographs of the Japanese Botanical Gardens in Austin provide an idea of the perspective control that different focal lengths allow the photographer to employ.
Nikkor DX 30mm
Nikkor DX 52mm
Nikkor DX 95mm
Nikkor DX 140mm
Nikkor 24mm
Granit 80mm
Granit 100mm
Granit 120mm
Granit 150mm
Granit 200mm
Granit 80mm + 2X Teleconverter
Granit 200mm + 2x Teleconverter
Dynamic Range
Before editing in Lightroom
After editing in Lightroom
Note: The dynamic range of a RAW image file is much higher than that of a processed JPEG file. This dynamic range can be utilized in editing software such as the adobe suit of programs to bring out otherwise dark shadows and bring down otherwose blown out highlights. This can be utilized to save otherwise ruined looking images, and can be helpful in a tight situation where you have accidentally shot a scene over or under exposed.
Dynamic range is a topic one could go into extreme depth on, but this should serve as a cursory overview of what one needs to know in order to get photos that look the way you want.
The dynamic range is roughly, the range of light levels within a scene over which a camera may record useable data at one time.
When a photograph is taken, the range over which light levels will be recorded at a pleasing value will be limited. This limit is set by the responsiveness of the sensor medium or film to incoming light. Given that digital sensors function at their root essentially as light meters, there is a peak value at which point no higher levels of light data may be recorded, known in the literature as a "well limit". This peak cutoff is depicted on the graph below, comparing the dynamic range of color 35mm Kodak Portra 160 film with a digital sesnor. The effect of this peak is that highlights will have no data recorded beyond a certain exposure value, severely limiting the dynamic range over which the sensor is able to record valuable data (an image).
This cuttoff in recording highlight detail is not seen in the response curve of the film tested, however it is to be noted that the signal to noise ratio of the film is significantly lower than that of digital sensors. This means that the "grain" of a film image will be inherently higher, but the overall ability to capture an image over a wider range of light levels will also be greater.
Further reading
Zone System by Ansel Adams, method of guaging the necessary exposure of a scene using the desired highlights and shadows
Citation:
https://corp.dxomark.com/wp-content/uploads/2017/11/2012-Film_vs_Digital_final_copyright.pdf
Bokeh, Explained
Bokeh is a Japanese word meaning "blur" or "haze."
This term has been used since 1997 to refer to an often very aesthestic blured foreground and/or background that is often utilized in creating certain atmospheres in cinema, and is used to focus the eyes attention on a subject in portraiture rather than their setting.
Older lenses will often display prominant spherical abberation in the shape of their respective bokeh. Functionally this is seen as pinpoints of light, otherwise perfectly round in a wide open lens, flattening towards the edges of the lens. This results in a circular pattern within any one Bokeh pattern on lenses with excessive spherical abberation
Optics Continued...
Chromatic Aberration:
Spherical Aberration:
These two things have plagued all forms of optics since man first looked through a camera obscura in ancient times. Initially longer focal lengths were used because the collimated nature of the light inherently brought all of the wavelenghts of visible light into better focus, which works great for telescopes, but inevitably more compact optics were needed to make more practical the burgeoning and novel art of photography in the mid 19th century. This led to the development of a number of different photographic lenses manufactured to reduce these aberrations. But it was not until 1954 that a Kodak optical engineer, who's position at Kodak comes entirely thanks to a personal recomendation from Albert Einstein himself, named Maximilian Herzberger invented the Superachromat a lens capable of bringing into reasonable focus all the wavelengths of light from IR to UV. Maximilian was denied a professorship at Jena University and forced to emigrate to the US by the increasing restrictions of the Nazi regime.
Literature
Here you will find an incomplete and costantly updating list of texts I have read in my studies of the photographic arts. It is my hopes that some of these texts will be of much assistance to any photographers in search of valuable historical and or practical resources.
Photographic Media Identification & Preservation:
Inception and Public Release of Photography:
Documents supplied in the original French, along with an english translation made the following decade.
Texts By Mike Ware:
Silver Processes
Blue Iron Processes
Gold Processes
Platinum Processes
Dictionary of Names
Mike Ware Resource Location:
https://www.mikeware.co.uk/mikeware/downloads.html
Important Figures in Photographic History
Scientists
Lippman
Carl Zeiss
German Lens ManufacturerWilliam Hershell
inventorof the CyanotypeHenry Niepce
Louis Daguere
George Eastman
Henry Foxtrot Talbot
lumieres
Nadar
Harold Eugene "Doc" Edgerton
Russell A. Kirsch
Dr. Richard Leach Maddox
Artists
Landscape
Ansel Adams
Portraiture
Architecture
War
Roger Fenton
Photojournalists
Alfred Stieglitz
Andy Warhol
Jean-Baptiste Gustave Le Gray-
"the most important French photographer of the nineteenth century"Robert Howlett
British PhotographerCarleton E. Watkins
Alexander Gardner
Julia Margaret Cameron
Andrew Joseph Russell
William Henry Jackson
Timothy H. O'Sullivan
Eadweard Muybridge
Wilhelm Conrad Röntgen
Clarence Hudson White
Louis Marie-Auguste Boutan
Frederick H. Evans
Edward Jean Steichen
Edward Sherriff Curtis
John T. Daniels
Lewis Hine
Ernest Joseph Bellocq
weegee
Jacques Henri Lartigue
Paul Strand
Edward Henry Weston
Man Ray
Rudolf Koppitz
August Sander
Erich Salomon
Henri Cartier-Bresson
Robert Doisneau
James Augustus Van Der Zee
Heinrich Hoffmann
Yevonde Philone Middleton
Dorothea Lange
Margaret Bourke-White
Robert Capa
Herbert List
Bill Brandt
Yousuf Karsh
Dmitri Baltermants
Gordon Roger Alexander Buchanan Parks
Frank Powolny
Joseph John Rosenthal
Yevgeny Ananyevich Khaldei
Alfred Eisenstaedt
Andreas Bernhard Lyonel Feininger
William Eugene Smith
Willy Ronis
Ralph Theodore Morse
Arthur Sasse
Hyman Peskin
Alfred Gregory
Ernest C. Withers
Ogle Winston Link
Alberto Díaz Gutiérrez
Peter Leibing
Abraham Zapruder
Charles Lee Moore
Early names for Photography:
Heliograph
Photogenic Drawing
Photogram
Photogene
Types of Photography:
Autochrome Lumiere
Daguerotype
Callotype
Ambrotype
Cyanotype
Albumen Print
Platinotype
Uranotype
Siderotype
Argyrotype
Chrysotype
Tintype
Wet Plate Collodion
Collodion Dry Plate
Gelatin Dry Plate
Ortho/Panchromatic Film
Reprography
Cinematography
Schlieren Photography
Infrared Photography
Kirlian Photography
Photogrammetry
Ultra Violet Photography
Hologram
Etymologies:
From the Greek etymologia, meaning the "study of the true sense (of a word)." Etymos meaning "true, real, actual" and -logia meaning "study of, a speaking of."
Abberation:
Aperture:
From the Latin apertura, meaning "an opening." The past participle of aperire, meaning "to open, uncover." Prot-Indo-European apo- meaning "off, away," and wer- meaning "to cover"Bulb
From the Greek bolbos, meaning "plant with round swelling on underground stem."Camera
From the Latin camera, meaning "a vault, vaulted room." Originally from Greek kamara, meaning "vaulted chamber, anything with an arched cover."Cinema
From the Greek kinetic, meaning motion.Depth
From the Proto.Indo.european. *dheub-, meaning "deep, hollow."Develop
From the French desveloper (variously spelled développer, desvoleper, or desvoloper) meaning to "unwrap, unfurl, unveil; reveal the meaning of, explain." Des- meaning "undo," and +veloper meaning "wrap up."Diffraction
From the Latin diffringere, meaning "break apart in pieces." Dis- meaning "apart" and +frangere meaning "to break."Digital
From the Latin digitus, meaning "finger or toe." As numbers under 10 were counted on the hands.Dynamic
From the Greek dynasthai, meaning "to be able, to have power, be strong enough."Expose
From the Latin exponere, meaning "set forth, lay open, exhibit, reveal, publish." Ex- meaning "from, forth," and +ponere meaning "to put, place."Fast
From the old English fæst, meaning "firmly fixed, steadfast, constant; secure; enclosed, watertight; strong, fortified."Film
From Proto-Germanic *fello(m), meaning "animal hide."Fix
From the Latin fixus, meaning "fixed, fast, immovable; established, settled."Flash
From the Proto-Indo-European *bhel-, meaning "to shine, flash, burn."ISO
From the Greek isos, meaning "equal."Landscape
From the Middle Dutch landscap, meaning "landscape." Land- meaning "region," and -scap meaning "ship, state, condition."Lens
From the Latin lens, genetive of lentis, meaning "lentil plant" as double convexed lenses resemble the seedds of this legumeLithograph
From the Greek words litho-, meaning "stone" and -graphie, meaning "to write, draw."Optics
From Greek optikos, meaning "of or having to do with sight." Optos meaning "seen, visible," and -ikos meaning "pertaining to."Orthochromatic
From Greek orthos-, meaning "correct, upright" and -chromatic, meaning "color."Panchromatic
From Greek pan-, meaning "all, every" and -chromatic, meaning "color."Panorama
From Greek pan-, meaning "all, every" and -horama, meaning "sight, spectacle, that which is seen."Photograph
From Greek phōs, meaning "light" and graphie, meaning "to write, draw."Portrait
From the Latin protrahere, meaning "to draw forth, paint" Pro-, meaning "forth" and trahere "to drag, draw."Pose
From Old French poser, meaning "put, place, propose." Derived from Latin pausare, meaning "to halt, rest, cease, pause," originally from the Greek pauein, meaning "to stop, hold back, arrest, to cause to cease." Confused meaning from Latin ponere, with no real etymological connection. Ponere coming from Proto.Indo.European. *apo-, meaning "off, away," and *sinere, meaning "to leave, let"Range
From Old French reng or renge, meaning "a row, line. rank."Shutter
From Middle English shitten, meaning "close; lock, fasten closed."Speed
From Old English sped, meaning "success; prosperity, riches, wealth; luck; opportunity, advancement."Time
From Proto-Germanic *timon-, meaning "time." Originally from Proto.Indo.European. di-mon-, di/da- meaning "to divide," and -mon possibly a suffix of action, state, or condition.Vision
From the Latin videre, meaning "to see"
Citation
https://www.etymonline.com/