Category: photography

 

https://www.studiobinder.com/blog/camera-lens-buying-guide/

 

https://www.studiobinder.com/blog/e-books/camera-lenses-explained-volume-1-ebook

Butterfly

Loop

Rembrandt

Split

Rim

Broad

Short

www.thisiscolossal.com/2021/04/reuben-wu-ex-stasis/

Wu programmed a stick of 200 LED lights to shift in color and shape above the calm landscapes. He captured the mesmerizing movements in-camera, and through a combination of stills, timelapse, and real-time footage, produced four audiovisual works that juxtapose the natural scenery with the artificially produced light and electronic sounds.

www.videomaker.com/article/c03/18984-how-to-calculate-contrast-ratios-for-more-professional-lighting-setups

 

 

To measure the contrast ratio you will need a light meter. The process starts with you measuring the main source of light, or the key light.

 

Get a reading from the brightest area on the face of your subject. Then, measure the area lit by the secondary light, or fill light. To make sense of what you have just measured you have to understand that the information you have just gathered is in F-stops, a measure of light. With each additional F-stop, for example going one stop from f/1.4 to f/2.0, you create a doubling of light. The reverse is also true; moving one stop from f/8.0 to f/5.6 results in a halving of the light.

 

Let’s say you grabbed a measurement from your key light of f/8.0. Then, when you measured your fill light area, you get a reading of f/4.0. This will lead you to a contrast ratio of 4:1 because there are two stops between f/4.0 and f/8.0 and each stop doubles the amount of light. In other words, two stops x twice the light per stop = four times as much light at f/8.0 than at f/4.0.

 

theslantedlens.com/2017/lighting-ratios-photo-video/

 

 

 

What Can’t Ratios Tell You?

Ratios are great but they don’t solve all the challenges of a lighting set up for a DP. Ratios help with the mood but there are a number of other factors that need to be considered as well.

1. Type of Lighting:

Soft light vs. Hard Light.  Ratios can’t help you determine whether to use soft light or hard light. You have to know what the differences are and when to employ them.

2. Direction of Lighting

Ratios can’t help you determine where the Key light should be coming from.

3. Color

Ratios are no good for color.  You have to develop your project and understand how the color temperature of lights impacts mood and feeling.

 

To get the most out of the images below you have to know what you are looking at. The FSI False Color is user adjustable (one of the reasons it is so powerful) and they way I have set it up reads like this.

 

RED = 3 Stops Over
Yellow = 2 Stops Over
Light Green = 1 Stop Over
Grey = Key
Teal = 1 Stop Under
Light Blue = 2 Stops Under
Dark Blue = 3 Stops Under
Black = 4 Stops Under

 

 

Replicating the fake color process through Foundry Nuke:

set cut_paste_input [stack 0]
version 13.2 v7
push $cut_paste_input
Expression {
expr0 "(r > 2) || (g > 2) || (b > 2) ? 3:0"
expr1 "((r > 1) && (r < 2)) || ((g > 1) && (g < 2)) || ((b > 1) && (b < 2))\n ? 2:0"
expr2 "((r > 0) && (r < 1)) || ((g > 0) && (g < 1)) || ((b > 0) && (b < 1))\n ? 1:0"
name Expression4
selected true
xpos 631
ypos 54
}
Blur {
size 100
filter quadratic
name Blur1
selected true
xpos 631
ypos 120
}

 

 

Blurring an image using the same scheme:

set cut_paste_input [stack 0]
version 13.2 v8
push $cut_paste_input
Dot {
name Dot27
selected true
xpos 446
ypos 2259
}
set N329d7800 [stack 0]
Expression {
expr0 "(r > 2) || (g > 2) || (b > 2) ? 3:0"
expr1 "((r > 1) && (r < 2)) || ((g > 1) && (g < 2)) || ((b > 1) && (b < 2))\n ? 2:0"
expr2 "((r > 0) && (r < 1)) || ((g > 0) && (g < 1)) || ((b > 0) && (b < 1))\n ? 1:0"
name Expression1
selected true
xpos 521
ypos 2167
}
set N66560500 [stack 0]
Shuffle2 {
fromInput1 {{0} B}
fromInput2 {{0} B}
mappings "4 black -1 -1 rgba.red 0 0 rgba.green 0 1 rgba.alpha 0 3 black -1 -1 rgba.blue 0 2 rgba.green 0 1 rgba.green 0 1"
name Shuffle7
selected true
xpos 621
ypos 2241
}
push $N329d7800
Copy {
inputs 2
from0 rgba.alpha
to0 rgba.alpha
name Copy1
selected true
xpos 621
ypos 2315
}
Blur {
size 50
maskChannelInput rgba.alpha
name Blur3
selected true
xpos 621
ypos 2384
}
push $N66560500
Shuffle2 {
fromInput1 {{0} B}
fromInput2 {{0} B}
mappings "4 black -1 -1 rgba.green 0 1 black -1 -1 rgba.red 0 0 rgba.blue 0 2 rgba.blue 0 2 rgba.blue 0 2 rgba.alpha 0 3"
name Shuffle1
selected true
xpos 730
ypos 2242
}
push $N329d7800
Copy {
inputs 2
from0 rgba.alpha
to0 rgba.alpha
name Copy2
selected true
xpos 793
ypos 2318
}
Blur {
size 100
maskChannelInput rgba.alpha
name Blur4
selected true
xpos 793
ypos 2380
}
Merge2 {
inputs 2
operation matte
name Merge3
selected true
xpos 621
ypos 2459
}
push $N66560500
Shuffle2 {
fromInput1 {{0} B}
fromInput2 {{0} B}
mappings "4 rgba.red 0 0 rgba.red 0 0 rgba.red 0 0 rgba.alpha 0 3 black -1 -1 rgba.blue 0 2 black -1 -1 rgba.green 0 1"
name Shuffle8
selected true
xpos 521
ypos 2241
}
push $N329d7800
Copy {
inputs 2
from0 rgba.alpha
to0 rgba.alpha
name Copy3
selected true
xpos 521
ypos 2315
}
Merge2 {
inputs 2
operation matte
name Merge5
selected true
xpos 521
ypos 2506
}

 

The two options together

 

set cut_paste_input [stack 0]
version 13.2 v8
push $cut_paste_input
Group {
 name FalseColorCompositionTest
 selected true
 xpos 389
 ypos 192
}
 BackdropNode {
  inputs 0
  name VIEWER_1
  xpos 458
  ypos -174
 }
 BackdropNode {
  inputs 0
  name VIEWER_2
  xpos 722
  ypos -108
  bdwidth 161
  bdheight 68
 }
 BackdropNode {
  inputs 0
  name VIEWER_3
  tile_color 0x8e8e8eff
  note_font_size 42
  xpos 738
  ypos 301
  bdheight 110
 }
 BackdropNode {
  inputs 0
  name VIEWER_4
  xpos 394
  ypos -43
 }
 Input {
  inputs 0
  name Input1
  xpos 467
  ypos -326
 }
 Dot {
  name DotIN
  xpos 501
  ypos -258
 }
 Dot {
  name Dot2
  label "\n"
  xpos 501
  ypos -144
 }
set N28599ad0 [stack 0]
 Dot {
  name Dot27
  xpos 611
  ypos -144
 }
set N2859e960 [stack 0]
 Expression {
  expr0 "(r > 2) || (g > 2) || (b > 2) ? 3:0"
  expr1 "((r > 1) && (r < 2)) || ((g > 1) && (g < 2)) || ((b > 1) && (b < 2))\n ? 2:0"
  expr2 "((r > 0) && (r < 1)) || ((g > 0) && (g < 1)) || ((b > 0) && (b < 1))\n ? 1:0"
  name Expression4
  xpos 828
  ypos -148
 }
push $N2859e960
 Expression {
  expr0 "(r > .6) || (g > .6) || (b > .6) ? 3:0"
  expr1 "((r > .22) && (r < .6)) || ((g > .22) && (g < .6)) || ((b > .22) && (b < .6))\n ? 2:0"
  expr2 "((r > 0) && (r < .22)) || ((g > 0) && (g < .22)) || ((b > 0) && (b < .22))\n ? 1:0"
  name Expression1
  xpos 710
  ypos -186
 }
 Switch {
  inputs 2
  name Switch1
  xpos 760
  ypos -78
 }
set N28650240 [stack 0]
 Dot {
  name Dot1
  xpos 878
  ypos 5
 }
set N286582c0 [stack 0]
 Shuffle2 {
  fromInput1 {{0} B}
  fromInput2 {{0} B}
  mappings "4 black -1 -1 rgba.red 0 0 rgba.green 0 1 rgba.alpha 0 3 black -1 -1 rgba.blue 0 2 rgba.green 0 1 rgba.green 0 1"
  name Shuffle7
  xpos 844
  ypos 41
 }
push $N2859e960
 Copy {
  inputs 2
  from0 rgba.alpha
  to0 rgba.alpha
  name Copy1
  xpos 844
  ypos 115
 }
 Blur {
  size 100
  maskChannelInput rgba.alpha
  name Blur3
  xpos 844
  ypos 184
 }
push $N286582c0
 Shuffle2 {
  fromInput1 {{0} B}
  fromInput2 {{0} B}
  mappings "4 black -1 -1 rgba.green 0 1 black -1 -1 rgba.red 0 0 rgba.blue 0 2 rgba.blue 0 2 rgba.blue 0 2 rgba.alpha 0 3"
  name Shuffle1
  xpos 953
  ypos 42
 }
push $N2859e960
 Copy {
  inputs 2
  from0 rgba.alpha
  to0 rgba.alpha
  name Copy2
  xpos 953
  ypos 111
 }
 Blur {
  size 200
  maskChannelInput rgba.alpha
  name Blur4
  xpos 953
  ypos 173
 }
 Merge2 {
  inputs 2
  operation matte
  name Merge3
  xpos 844
  ypos 259
 }
push $N286582c0
 Shuffle2 {
  fromInput1 {{0} B}
  fromInput2 {{0} B}
  mappings "4 rgba.red 0 0 rgba.red 0 0 rgba.red 0 0 rgba.alpha 0 3 black -1 -1 rgba.blue 0 2 black -1 -1 rgba.green 0 1"
  name Shuffle8
  xpos 744
  ypos 41
 }
push $N2859e960
 Copy {
  inputs 2
  from0 rgba.alpha
  to0 rgba.alpha
  name Copy3
  xpos 744
  ypos 115
 }
 Merge2 {
  inputs 2
  operation matte
  name Merge5
  xpos 744
  ypos 354
 }
push $N28650240
push $N28599ad0
 Saturation {
  saturation 0
  name Saturation1
  xpos 398
  ypos -15
 }
push $N28599ad0
 ContactSheet {
  inputs 4
  width 6100
  height 2501
  rows 1
  center true
  name ContactSheet1
  xpos 482
  ypos 437
 }
 Dot {
  name DotOUT
  xpos 512
  ypos 553
 }
 Output {
  name Output1
  xpos 478
  ypos 630
 }
end_group

 

www.studiobinder.com/blog/academy-award-for-best-cinematography-winners

 

2019 – Roger Deakins, 1917
2018 – Alfonso Cuarón, Roma
2017 – Roger Deakins, Blade Runner 2049
2016 – Linus Sandgren, La La Land
2015 – Emmanuel Lubezki, The Revenant
2014 – Emmanuel Lubezki, Birdman or (The Unexpected Virtue of Ignorance)
2013 – Emmanuel Lubezki, Gravity
2012 – Claudio Miranda, Life of Pi
2011 – Robert Richardson, Hugo
2010 – Wally Pfister, Inception
2009 – Mauro Fiore, Avatar
2008 – Anthony Dod Mantle, Slumdog Millionaire
2007 – Robert Elswit, There Will Be Blood
2006 – Guillermo Navarro, Pan’s Labyrinth
2005 – Dion Beebe, Memoirs of a Geisha
2004 – Robert Richardson, The Aviator
2003 – Russell Boyd, Master and Commander: The Far Side of the World
2002 – Conrad L. Hall, Road to Perdition
2001 – Andrew Lesnie, The Lord of the Rings: The Fellowship of the Ring
2000 – Peter Pau, Crouching Tiger, Hidden Dragon
1999 – Conrad L. Hall, American Beauty
1998 – Janusz Kamiński, Saving Private Ryan
1997 – Russell Carpenter, Titanic
1996 – John Seale, The English Patient
1995 – John Toll, Braveheart
1994 – John Toll, Legends of the Fall
1993 – Janusz Kamiński, Schindler’s List
1992 – Phillipe Rousselot, A River Runs Through It
1991 – Robert Richardson, JFK
1990 – Dean Semler, Dances with Wolves
1989 – Freddie Francis, Glory
1988 – Peter Biziou, Mississippi Burning
1987 – Vittorio Storaro, The Last Emperor
1986 – Chris Menges, The Mission
1985 – David Watkin, Out of Africa
1984 – Chris Menges, The Killing Fields
1983 – Sven Nykvist, Fanny and Alexander
1982 – Billy Williams, Ronnie Taylor, Gandhi
1981 – Vittorio Storaro, Reds
1980 – Geoffrey Unsworth, Ghislain Cloquet, Tess
1979 – Vittorio Storaro, Apocalypse Now
1978 – Néstor Almendros, Days of Heaven
1977 – Vilmos Zsigmond, Close Encounters of the Third Kind
1976 – Haskell Wexler, Bound for Glory
1975 – John Alcott, Barry Lyndon
1974 – Fred J. Koenekamp, Joseph Biroc, The Towering Inferno
1973 – Sven Nykvist, Cries and Whispers
1972 – Geoffrey Unsworth, Cabaret
1971 – Oswald Morris, Fiddler on the Roof
1970 – Freddie Young, Ryan’s Daughter
1969 – Conrad Hall, Butch Cassidy and the Sundance Kid
1968 – Pasqualino De Santis, Romeo and Juliet
1967 – Burnett Guffey, Bonnie and Clyde
1966 – Ted Moore, (Color) A Man for All Seasons
Haskell Wexler, (B&W) Who’s Afraid of Virginia Woolf?
1965 – Freddie Young, (Color) Doctor Zhivago
(Ernest Laszlo), (B&W) Ship of Fools
1964 – Harry Stradling, (Color) My Fair Lady (
Walter Lassally, (B&W) Zorba the Greek
1963 – Leon Shamroy, (Color) Cleopatra
James Wong Howe, (B&W) Hud
1962 – Freddie Young, (Color) Lawrence of Arabia
Jean Bourgoin, Walter Wottitz, (B&W) The Longest Day
1961 – Daniel L. Fapp, (Color) West Side Story
Eugen Schüfftan, (B&W) The Hustler
1960 – Russell Metty, (Color) Spartacus
Freddie Francis, (B&W) Sons and Lovers
1959 – Robert Surtees, (Color) Ben-Hur
William C. Mellor, (B&W) The Diary of Anne Frank
1958 – Joseph Ruttenberg, (Color) Gigi
Sam Leavitt, (B&W) The Defiant Ones
1957 – Jack Hildyard, The Bridge on the River Kwai
1956 – Lionel Lindon, (Color) Around the World in 80 Days
Joseph Ruttenberg, (B&W) Somebody Up There Likes Me
1955 – Robert Burks, (Color) To Catch a Thief
James Wong Howe, (B&W) The Rose Tattoo
1954 – Milton Krasner, (Color) Three Coins in the Fountain
Boris Kaufman, (B&W) On the Waterfront
1953 – Loyal Griggs, (Color) Shane
Burnett Guffey, (B&W) From Here to Eternity
1952 – Winton C. Hoch, Archie Stout, (Color) The Quiet Man
Robert Surtees, (B&W) The Bad and the Beautiful
1951 – Alfred Gilks, John Alton, (Color) An American in Paris
William C. Mellor, (B&W) A Place in the Sun
1950 – Robert Surtees, (Color) King Solomon’s Mines
Robert Krasker, (B&W) The Third Man
1949 – Winton C. Hoch, (Color) She Wore a Yellow Ribbon
Paul C. Vogel, (B&W) Battleground
1948 – Joseph Valentine, William V. Skall, Winton C. Hoch, (Color) Joan of Arc
William Daniels, (B&W) The Naked City
1947 – Jack Cardiff, (Color) Black Narcissus
Guy Green, (B&W) Great Expectations
1946 – Charles Rosher, Leonard Smith, Arthur Arling, (Color) The Yearling
Arthur C. Miller, (B&W) Anna and the King of Siam
1945 – Leon Shamroy, (Color) Leave Her to Heaven
Harry Stradling, (B&W) The Picture of Dorian Gray
1944 – Leon Shamroy, (Color) Wilson
Joseph LaShelle, (B&W) Laura
1943 – Hal Mohr, W. Howard Greene, (Color) Phantom of the Opera
Arthur C. Miller, (B&W) The Song of Bernadette
1942 – Leon Shamroy, (Color) The Black Swan
Joseph Ruttenberg, (B&W) Mrs. Miniver
1941 – Ernest Haller, Ray Rennahan, (Color) Blood and Sand
Arthur C. Miller, (B&W) How Green Was My Valley
1940 – George Périnal, (Color) Thief of Bagdad
George Barnes, (B&W) Rebecca
1939 – Ernest Haller, Ray Rennahan, (Color) Gone with the Wind
Gregg Toland, (B&W) Wuthering Heights
1938 – Oliver T. Marsh, Allen Davey, (Color) Sweethearts
Joseph Ruttenberg, (B&W) The Great Waltz
1937 – W. Howard Greene, (Color) A Star is Born
Karl Freund, (B&W) The Good Earth
1936 – W. Howard Greene, Harold Rossen, (Color) The Garden of Allah
Tony Guadio, (B&W) Anthony Adverse
1935 – Hal Mohr, A Midsummer Night’s Dream
1934 – Victor Milner, Cleopatra
1933/32 – Charles Lang, A Farewell to Arms
1932/31 – Lee Garmes, Shanghai Express
1931/30 – Floyd Crosby, Tabu: A Story of the South Seas
1930/29 – Joseph T. Rucker, Willard Van der Veer, With Byrd at the South Pole
1929/28 – Clyde De Vinna, White Shadows in the South Seas
1928/27 – Charles Rosher, Karl Struss, Sunrise: A Song of Two Humans

www.studiobinder.com/blog/full-frame-vs-crop-sensor

https://petapixel.com/2021/03/16/photographer-spends-12-years-1250-hours-exposing-photo-of-milky-way/

 

 

 

 

www.myheritage.com/deep-nostalgia

www.bbc.com/news/technology-56210053

https://us.rosco.com/en/products/family/gobos

 

www.xuanprada.com/blog/2014/11/3/hdri-shooting

 

http://blog.gregzaal.com/2016/03/16/make-your-own-hdri/

 

http://blog.hdrihaven.com/how-to-create-high-quality-hdri/

 

Shooting checklist

• Full coverage of the scene (fish-eye shots)
• Backplates for look-development (including ground or floor)
• Macbeth chart for white balance
• Grey ball for lighting calibration
• Chrome ball for lighting orientation
• Basic scene measurements
• Material samples
• Individual HDR artificial lighting sources if required

Methodology

• Plant the tripod where the action happens, stabilise it and level it
• Set manual focus
• Set white balance
• Set ISO
• Set raw+jpg
• Set apperture
• Metering exposure
• Set neutral exposure
• Read histogram and adjust neutral exposure if necessary
• Shot slate (operator name, location, date, time, project code name, etc)
• Set auto bracketing
• Shot 5 to 7 exposures with 3 stops difference covering the whole environment
• Place the aromatic kit where the tripod was placed, and take 3 exposures. Keep half of the grey sphere hit by the sun and half in shade.
• Place the Macbeth chart 1m away from tripod on the floor and take 3 exposures
• Take backplates and ground/floor texture references
• Shoot reference materials
• Write down measurements of the scene, specially if you are shooting interiors.
• If shooting artificial lights take HDR samples of each individual lighting source.

Exposures starting point

• Day light sun visible ISO 100 F22
• Day light sun hidden ISO 100 F16
• Cloudy ISO 320 F16
• Sunrise/Sunset ISO 100 F11
• Interior well lit ISO 320 F16
• Interior ambient bright ISO 320 F10
• Interior bad light ISO 640 F10
• Interior ambient dark ISO 640 F8
• Low light situation ISO 640 F5

https://www.researchgate.net/publication/342521609_CAMERA_PROJECTION_MAPPING_FOR_ENVIRONMENTS_IN_NUKE

Also see: http://www.pixelsham.com/2015/05/16/how-aperture-shutter-speed-and-iso-affect-your-photos/

 

In photography, exposure value (EV) is a number that represents a combination of a camera’s shutter speed and f-number, such that all combinations that yield the same exposure have the same EV (for any fixed scene luminance).

 

 

The EV concept was developed in an attempt to simplify choosing among combinations of equivalent camera settings. Although all camera settings with the same EV nominally give the same exposure, they do not necessarily give the same picture. EV is also used to indicate an interval on the photographic exposure scale. 1 EV corresponding to a standard power-of-2 exposure step, commonly referred to as a stop

 

EV 0 corresponds to an exposure time of 1 sec and a relative aperture of f/1.0. If the EV is known, it can be used to select combinations of exposure time and f-number.

 

https://www.streetdirectory.com/travel_guide/141307/photography/exposure_value_ev_and_exposure_compensation.html

Note EV does not equal to photographic exposure. Photographic Exposure is defined as how much light hits the camera’s sensor. It depends on the camera settings mainly aperture and shutter speed. Exposure value (known as EV) is a number that represents the exposure setting of the camera.

 

Thus, strictly, EV is not a measure of luminance (indirect or reflected exposure) or illuminance (incidental exposure); rather, an EV corresponds to a luminance (or illuminance) for which a camera with a given ISO speed would use the indicated EV to obtain the nominally correct exposure. Nonetheless, it is common practice among photographic equipment manufacturers to express luminance in EV for ISO 100 speed, as when specifying metering range or autofocus sensitivity.

 

The exposure depends on two things: how much light gets through the lenses to the camera’s sensor and for how long the sensor is exposed. The former is a function of the aperture value while the latter is a function of the shutter speed. Exposure value is a number that represents this potential amount of light that could hit the sensor. It is important to understand that exposure value is a measure of how exposed the sensor is to light and not a measure of how much light actually hits the sensor. The exposure value is independent of how lit the scene is. For example a pair of aperture value and shutter speed represents the same exposure value both if the camera is used during a very bright day or during a dark night.

 

Each exposure value number represents all the possible shutter and aperture settings that result in the same exposure. Although the exposure value is the same for different combinations of aperture values and shutter speeds the resulting photo can be very different (the aperture controls the depth of field while shutter speed controls how much motion is captured).

EV 0.0 is defined as the exposure when setting the aperture to f-number 1.0 and the shutter speed to 1 second. All other exposure values are relative to that number. Exposure values are on a base two logarithmic scale. This means that every single step of EV – plus or minus 1 – represents the exposure (actual light that hits the sensor) being halved or doubled.

https://www.streetdirectory.com/travel_guide/141307/photography/exposure_value_ev_and_exposure_compensation.html

 

Formula

https://en.wikipedia.org/wiki/Exposure_value

 

https://www.scantips.com/lights/math.html

 

which means   2^EV = N² / t

where

• N is the relative aperture (f-number) Important: Note that f/stop values must first be squared in most calculations
• t is the exposure time (shutter speed) in seconds

EV 0 corresponds to an exposure time of 1 sec and an aperture of f/1.0.

Example: If f/16 and 1/4 second, then this is:

(N² / t) = (16 × 16 ÷ 1/4) = (16 × 16 × 4) = 1024.

Log₂(1024) is EV 10. Meaning, 2¹⁰ = 1024.

 

Collecting photographic exposure using Light Meters

https://photo.stackexchange.com/questions/968/how-can-i-correctly-measure-light-using-a-built-in-camera-meter

The exposure meter in the camera does not know whether the subject itself is bright or not. It simply measures the amount of light that comes in, and makes a guess based on that. The camera will aim for 18% gray, meaning if you take a photo of an entirely white surface, and an entirely black surface you should get two identical images which both are gray (at least in theory)

https://en.wikipedia.org/wiki/Light_meter

For reflected-light meters, camera settings are related to ISO speed and subject luminance by the reflected-light exposure equation:

where

• N is the relative aperture (f-number)
• t is the exposure time (“shutter speed”) in seconds
• L is the average scene luminance
• S is the ISO arithmetic speed
• K is the reflected-light meter calibration constant

 

For incident-light meters, camera settings are related to ISO speed and subject illuminance by the incident-light exposure equation:

where

• E is the illuminance (in lux)
• C is the incident-light meter calibration constant

 

Two values for K are in common use: 12.5 (Canon, Nikon, and Sekonic) and 14 (Minolta, Kenko, and Pentax); the difference between the two values is approximately 1/6 EV.
For C a value of 250 is commonly used.

 

Nonetheless, it is common practice among photographic equipment manufacturers to also express luminance in EV for ISO 100 speed. Using K = 12.5, the relationship between EV at ISO 100 and luminance L is then :

L = 2^(EV-3)

 

The situation with incident-light meters is more complicated than that for reflected-light meters, because the calibration constant C depends on the sensor type. Illuminance is measured with a flat sensor; a typical value for C is 250 with illuminance in lux. Using C = 250, the relationship between EV at ISO 100 and illuminance E is then :

 

E = 2.5 * 2^(EV)

 

https://nofilmschool.com/2018/03/want-easier-and-faster-way-calculate-exposure-formula

Three basic factors go into the exposure formula itself instead: aperture, shutter, and ISO. Plus a light meter calibration constant.

f-stop²/shutter (in seconds) = lux * ISO/C

 

If you at least know four of those variables, you’ll be able to calculate the missing value.

So, say you want to figure out how much light you’re going to need in order to shoot at a certain f-stop. Well, all you do is plug in your values (you should know the f-stop, ISO, and your light meter calibration constant) into the formula below:

lux = C (f-stop²/shutter (in seconds))/ISO

 

Exposure Value Calculator:

https://www.vroegop.nu/exposure-value-calculator/

 

From that perspective, an exposure stop is a measurement of Exposure and provides a universal linear scale to measure the increase and decrease in light, exposed to the image sensor, due to changes in shutter speed, iso & f-stop.
+-1 stop is a doubling or halving of the amount of light let in when taking a photo.
1 EV is just another way to say one stop of exposure change.

 

One major use of EV (Exposure Value) is just to measure any change of exposure, where one EV implies a change of one stop of exposure. Like when we compensate our picture in the camera.

 

If the picture comes out too dark, our manual exposure could correct the next one by directly adjusting one of the three exposure controls (f/stop, shutter speed, or ISO). Or if using camera automation, the camera meter is controlling it, but we might apply +1 EV exposure compensation (or +1 EV flash compensation) to make the result goal brighter, as desired. This use of 1 EV is just another way to say one stop of exposure change.

 

On a perfect day the difference from sampling the sky vs the sun exposure with diffusing spot meters is about 3.2 exposure difference.

 ~15.4 EV for the sun
 ~12.2 EV for the sky

That is as a ballpark. All still influenced by surroundings, accuracy parameters, fov of the sensor…

 

 

EV calculator

https://www.scantips.com/lights/evchart.html#calc

http://www.fredparker.com/ultexp1.htm

 

Exposure value is basically used to indicate an interval on the photographic exposure scale, with a difference of 1 EV corresponding to a standard power-of-2 exposure step, also commonly referred to as a “stop”.

 

https://contrastly.com/a-guide-to-understanding-exposure-value-ev/

 

Retrieving photographic exposure from an image

IF you are still trying to gauge relative brightness, the level of the sun in Nuke can vary, but it should be in the thousands. Ie: between 30,000 and 65,0000 rgb value depending on time of the day, season and atmospherics.

 

The values for a 12 o’clock sun, with the sun sampled at EV 15.5 (shutter 1/30, ISO 100, F22) is 32.000 RGB max values (or 32,000 pixel luminance).
The thing to keep an eye for is the level of contrast between sunny side/fill side.  The terminator should be quite obvious,  there can be up to 3 stops difference between fill/key in sunny lit objects.

 

Note: In Foundry’s Nuke, the software will map 18% gray to whatever your center f/stop is set to in the viewer settings (f/8 by default… change that to EV by following the instructions below).
You can experiment with this by attaching an Exposure node to a Constant set to 0.18, setting your viewer read-out to Spotmeter, and adjusting the stops in the node up and down. You will see that a full stop up or down will give you the respective next value on the aperture scale (f8, f11, f16 etc.).
One stop doubles or halves the amount or light that hits the filmback/ccd, so everything works in powers of 2.
So starting with 0.18 in your constant, you will see that raising it by a stop will give you .36 as a floating point number (in linear space), while your f/stop will be f/11 and so on.

If you set your center stop to 0 (see below) you will get a relative readout in EVs, where EV 0 again equals 18% constant gray.
Note: make sure to set your Nuke read node to ‘raw data’

 

In other words. Setting the center f-stop to 0 means that in a neutral plate, the middle gray in the macbeth chart will equal to exposure value 0. EV 0 corresponds to an exposure time of 1 sec and an aperture of f/1.0.

 

To switch Foundry’s Nuke’s SpotMeter to return the EV of an image, click on the main viewport, and then press s, this opens the viewer’s properties. Now set the center f-stop to 0 in there. And the SpotMeter in the viewport will change from aperture and fstops to EV.

 

If you are trying to gauge the EV from the pixel luminance in the image:
– Setting the center f-stop to 0 means that in a neutral plate, the middle 18% gray will equal to exposure value 0.
– So if EV 0 = 0.18 middle gray in nuke which equal to a pixel luminance of 0.18, doubling that value, doubles the EV.

.18 pixel luminance = 0EV
.36 pixel luminance = 1EV
.72 pixel luminance = 2EV
1.46 pixel luminance = 3EV
...

 

This is a Geometric Progression function: x_n = ar^(n-1)

The most basic example of this function is 1,2,4,8,16,32,… The sequence starts at 1 and doubles each time, so

• a=1 (the first term)
• r=2 (the “common ratio” between terms is a doubling)

And we get:

{a, ar, ar², ar³, … }

= {1, 1×2, 1×2², 1×2³, … }

= {1, 2, 4, 8, … }

In this example the function translates to: n = 2^(n-1)
You can graph this curve through this expression: x = 2^(y-1)  :

You can go back and forth between the two values through a geometric progression function and a log function:

(Note: in a spreadsheet this is: = POWER(2; cell# -1)  and  =LOG(cell#, 2)+1) )

2(y-1)	log2(x)+1
x	y
1	1
2	2
4	3
8	4
16	5
32	6
64	7
128	8
256	9
512	10
1024	11
2048	12
4096	13

 

Translating this into a geometric progression between an image pixel luminance and EV:

(more…)

noahwitchell.com
http://www.noahwitchell.com/freebies

 

locationtextures.com
https://locationtextures.com/panoramas/

 

maxroz.com
https://www.maxroz.com/hdri/list

 

HDRI Haven
https://hdrihaven.com/

 

Poly Haven
https://polyhaven.com/hdris

 

Domeble
https://www.domeble.com/

 

IHDRI
https://www.ihdri.com/

 

HDRMaps
https://hdrmaps.com/

 

NoEmotionHdrs.net
http://noemotionhdrs.net/hdrday.html

 

OpenFootage.net
https://www.openfootage.net/hdri-panorama/

 

HDRI-hub
https://www.hdri-hub.com/hdrishop/hdri

.zwischendrin
https://www.zwischendrin.com/en/browse/hdri

Longer list here:

https://cgtricks.com/list-sites-free-hdri/

 

www.sharegrid.com/learn/lens-test-data

www.sharegrid.com/learn/the-3-tests

www.sharegrid.com/learn/lens-test-approach

https://ciechanow.ski/cameras-and-lenses/

 

 

shotdeck.com

https://www.studiobinder.com/blog/different-types-camera-lenses-explained/?utm_campaign=Weekly_Newsletter&utm_medium=email&utm_source=sendgrid&utm_term=types-of-camera-lenses-sendgrid&utm_content=types-of-camera-lenses-sendgrid

Virtual Production Field Guide

 

v1.2.02 Local copy:

 

 

gumroad.com/l/XUOQrK

bernardsmith.eu/computatrum/scan_and_restore_archive_and_print/scanning/

github.com/colour-science/colour-checker-detection

A Python package implementing various colour checker detection algorithms and related utilities.

 

The 300dpi digital poster is now available to all PixelSham.com subscribers.

 

If you have already subscribed and wish a copy, please send me a note through the contact page.