For beginers - Introduction to exposure
Jan 13, 2019 16:37:42 #
Shutter Speed.
The Shutter
Controls how long the sensor is exposed to the light.
The shutter is like a door in front of the sensor and is normally closed and only opens for the exposure.
The time the shutter is open is expressed in seconds or fractions of a second.
Shutter speed settings.
(1) Must be set to ensure correct exposure along with aperture and Sensor ISO settings.
(2) Must be fast enough to prevent camera movement resulting in un sharp photographs.
When hand holding, a guideline is that 1/focal length of the lens (in 35mm terms) = the shutter speed.
On a consumer SLR the sensor is smaller than a film (35mm) sensor
So with 18-55 "kit lens" lens (28-80 mm in 35mm film camera terms) the shutter speed used should be 1/30 second at the wide end and 1/75 second at the long end or faster.
If the camera/lens that has image stabilistion or vibration reduction than these shutter speeds can be reduced (see your camera/lens instruction book)
(3) If required must be fast enough to stop subject motion.
(4) Can be used creatively eg, subject motion and panning.
Examples:
(1) 1/10 @ F6.3, ISO 1600
This was shot hand held with an image stabilised lens.
Notice the scene and onlookers are sharp, however the shutter speed wasn't fast enough to freeze the motion of the walking girls.
.
The Shutter
Controls how long the sensor is exposed to the light.
The shutter is like a door in front of the sensor and is normally closed and only opens for the exposure.
The time the shutter is open is expressed in seconds or fractions of a second.
Shutter speed settings.
(1) Must be set to ensure correct exposure along with aperture and Sensor ISO settings.
(2) Must be fast enough to prevent camera movement resulting in un sharp photographs.
When hand holding, a guideline is that 1/focal length of the lens (in 35mm terms) = the shutter speed.
On a consumer SLR the sensor is smaller than a film (35mm) sensor
So with 18-55 "kit lens" lens (28-80 mm in 35mm film camera terms) the shutter speed used should be 1/30 second at the wide end and 1/75 second at the long end or faster.
If the camera/lens that has image stabilistion or vibration reduction than these shutter speeds can be reduced (see your camera/lens instruction book)
(3) If required must be fast enough to stop subject motion.
(4) Can be used creatively eg, subject motion and panning.
Examples:
(1) 1/10 @ F6.3, ISO 1600
This was shot hand held with an image stabilised lens.
Notice the scene and onlookers are sharp, however the shutter speed wasn't fast enough to freeze the motion of the walking girls.
.
Jan 13, 2019 16:40:36 #
Here the relatively high shutter speed, 1/500 second, has frozen the action. The rider was ok.
Camera Canon EOS 40D
Exposure 0.002 sec (1/500)
Aperture f/10
Focal Length 400 mm
ISO Speed 400
.
Camera Canon EOS 40D
Exposure 0.002 sec (1/500)
Aperture f/10
Focal Length 400 mm
ISO Speed 400
.
Jan 13, 2019 16:43:17 #
Relatively slow shutter speed, 1/100 second, and smoothly tracked vehicle whilst shooting (panning). Notice the wheels are blurred, as well as the background.
Camera Canon EOS 5D
Exposure 0.01 sec (1/100)
Aperture f/16.0
Focal Length 80 mm
ISO Speed 100
.
Camera Canon EOS 5D
Exposure 0.01 sec (1/100)
Aperture f/16.0
Focal Length 80 mm
ISO Speed 100
.
Jan 13, 2019 17:03:19 #
If the camera is supported by a tripod, or some other object, you can shoot at much longer shutter speeds. In this case 3 seconds.
Camera Canon EOS 5D
Exposure 3.2 (Seconds)
Aperture f/8.0
Focal Length 45 mm
ISO Speed 200
More to come (in a few hours).
Camera Canon EOS 5D
Exposure 3.2 (Seconds)
Aperture f/8.0
Focal Length 45 mm
ISO Speed 200
More to come (in a few hours).
Jan 13, 2019 19:43:16 #
Putting it all together
The first I set is the ISO, usually to the lowest I think I will need for the available lighting conditions.
What ISO do I want?
(1) If I am using a tripod I can keep the ISO as low as possible. Nowdays if shooting in aperture priority I will use autoi ISO
(2) If Hand holding I will take in to consideration what lens I am using (so I can shoot at high enough shutter speed to prevent camera shake) and my lenses maximum aperture.
A guide is the old "Sunny 16" rule which states, when shooting on a bright sunny say, Exposure = 1/ISO @ F16
So if shooting at ISO 100 that will give me a choice of;
1/50 @ F22
1/100 @ F16 ********* Sunny 16
1/200 @ F11
1/400 @ F8
1/800 @ F5.6
1/1600 @ F4
1/3200 @ F2.8
1/6400 @ F2
(3) What are the lighting/weather conditions like.
In the shade or overcast I will be thinking at least ISO 400
In heavy rain or very late afternoon it will be 800 +
And available light indoor and of an evening it will be 1600(+)
Indoor and available light - Shooting hand held with an Image stabilised lens. I selected ISO 3200
Camera Canon EOS 5D
Exposure 0.05 sec (1/20)
Aperture f/5.0
Focal Length 24 mm
ISO Speed 3200
Exposure Bias -2/3 EV
Flash Off, Did not fire
.
The first I set is the ISO, usually to the lowest I think I will need for the available lighting conditions.
What ISO do I want?
(1) If I am using a tripod I can keep the ISO as low as possible. Nowdays if shooting in aperture priority I will use autoi ISO
(2) If Hand holding I will take in to consideration what lens I am using (so I can shoot at high enough shutter speed to prevent camera shake) and my lenses maximum aperture.
A guide is the old "Sunny 16" rule which states, when shooting on a bright sunny say, Exposure = 1/ISO @ F16
So if shooting at ISO 100 that will give me a choice of;
1/50 @ F22
1/100 @ F16 ********* Sunny 16
1/200 @ F11
1/400 @ F8
1/800 @ F5.6
1/1600 @ F4
1/3200 @ F2.8
1/6400 @ F2
(3) What are the lighting/weather conditions like.
In the shade or overcast I will be thinking at least ISO 400
In heavy rain or very late afternoon it will be 800 +
And available light indoor and of an evening it will be 1600(+)
Indoor and available light - Shooting hand held with an Image stabilised lens. I selected ISO 3200
Camera Canon EOS 5D
Exposure 0.05 sec (1/20)
Aperture f/5.0
Focal Length 24 mm
ISO Speed 3200
Exposure Bias -2/3 EV
Flash Off, Did not fire
.
Jan 13, 2019 19:49:10 #
(4) What shutter speed and aperture do I want and what ISO will give it to me?
In poor light, and lens dependant you may need to make compromises.
What shooting mode?
If shutter speed is important, either to prevent problems with camera or subject movement, freeze action, or for creative use like panning then I will use shutter priority and an ISO to give me an aperture of around F8-F11 at the shutter speed I want to use.
In this example I wanted to freeze the action.
Canon EOS 40D + EF100-400mm f/4.5-5.6L IS USM
1/100 @ ƒ/8.0, ISO 400 and F=400mm
Flash (off, did not fire)
.
.
In poor light, and lens dependant you may need to make compromises.
What shooting mode?
If shutter speed is important, either to prevent problems with camera or subject movement, freeze action, or for creative use like panning then I will use shutter priority and an ISO to give me an aperture of around F8-F11 at the shutter speed I want to use.
In this example I wanted to freeze the action.
Canon EOS 40D + EF100-400mm f/4.5-5.6L IS USM
1/100 @ ƒ/8.0, ISO 400 and F=400mm
Flash (off, did not fire)
.
.
Jan 13, 2019 19:52:18 #
If aperture is important, to control depth of field (DOF) then I will use aperture priority and select an ISO that will give me a shutter speed where camera shake or subject movement wouldn't be a problem.
I mostly use it for shallow DOF pics to isolate subjects from backgrounds.
This was an historical fashion parade, in a city street and I wanted to isolate the model from the messy background so I used an aperture of F2 on a 135mm lens.
Camera Canon EOS 40D
Exposure 0.001 sec (1/1600)
Aperture f/2.0
Focal Length 135 mm
ISO Speed 100
Exposure Bias -2/3 EV
.
I mostly use it for shallow DOF pics to isolate subjects from backgrounds.
This was an historical fashion parade, in a city street and I wanted to isolate the model from the messy background so I used an aperture of F2 on a 135mm lens.
Camera Canon EOS 40D
Exposure 0.001 sec (1/1600)
Aperture f/2.0
Focal Length 135 mm
ISO Speed 100
Exposure Bias -2/3 EV
.
Jan 13, 2019 19:57:40 #
In poor light I will be in aperture priority mode and at or near maximum ISO and take what ever shutter speed I can get.
Shortly after sunset.
Camera Canon EOS 40D
Exposure 0.003 sec (1/400)
Aperture f/5.6 (Wide open)
Focal Length 260 mm
ISO Speed 3200 (Maximum)
Exposure Bias -2/3 EV
.
Shortly after sunset.
Camera Canon EOS 40D
Exposure 0.003 sec (1/400)
Aperture f/5.6 (Wide open)
Focal Length 260 mm
ISO Speed 3200 (Maximum)
Exposure Bias -2/3 EV
.
Jan 13, 2019 20:06:05 #
Finally if I want total control I will be shooting manual exposure.
I mainly use it for night shots, macro's, & difficult lighting conditions.
This example was on a dawn shoot and I was using a 3 stop soft ND grad filter to control the sky.
It really did go "off" that morning.
Canon EOS 5D + Canon EF28-135mm f/3.5-5.6 IS USM
1 second @ ƒ/8.0 ISO 50 and F=28mm
That's about it and feel free to contribute and/or ask questions.
-------------------------------
The main thing to remember it is a "balancing act".
ISO, shutter speed and aperture all work together and normally if you change one you change the other.
.
I mainly use it for night shots, macro's, & difficult lighting conditions.
This example was on a dawn shoot and I was using a 3 stop soft ND grad filter to control the sky.
It really did go "off" that morning.
Canon EOS 5D + Canon EF28-135mm f/3.5-5.6 IS USM
1 second @ ƒ/8.0 ISO 50 and F=28mm
That's about it and feel free to contribute and/or ask questions.
-------------------------------
The main thing to remember it is a "balancing act".
ISO, shutter speed and aperture all work together and normally if you change one you change the other.
.
Jan 14, 2019 05:09:26 #
In the shot from the fashion parade, could you explain what you were protecting when you used an exposure compensation setting (exposure bias) of -2/3.
Jan 14, 2019 06:24:36 #
Very much appreciate this thread; I have some knowledge (I would call myself a somewhat advanced amateur), but the suggestions are both good and valid. Thanks!
Jan 14, 2019 06:46:19 #
Jan 14, 2019 06:53:42 #
Richard, your discussion is outstanding. I have printed it to let my lady friend, whom I'm teaching photography, read and study. Thank you for the time you spent.
Jan 14, 2019 07:12:51 #
R.G. wrote:
In the shot from the fashion parade, could you explain what you were protecting when you used an exposure compensation setting (exposure bias) of -2/3.
From memory, it was a cloudless winters day (very bright sunshine) and all the model pics were shot around 1pm. They all have an EV of -2/3 or -1. I do not chimp after every shot, just every now and again on these shoots, however I probably had a "blinkies" indication (over exposure) so I reduced the exposure a bit to correct it.
Jan 14, 2019 07:13:23 #
jeffhacker wrote:
Very much appreciate this thread; I have some knowledge (I would call myself a somewhat advanced amateur), but the suggestions are both good and valid. Thanks!
Thanks very much.
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