Specialists in medium and large format photographic equipment

What is EV (Exposure Value)?

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[fusion_text]Exposure Values were launched in 1954 by the Prontor shutter company at the Photokina event. Originally they were called LV (Light Values) then renamed to EV (Exposure Values). The EV summarises all equivalent combinations of shutter and aperture, to provide a single exposure. For example, the EV 1 value means the following set up exposures:

Be aware that the EV does not take into account film speed. This third factor is controlled separately by what film you load into the camera! You will need to set the appropriate film speed on your light meter, otherwise you will not get the correct light readings.[/fusion_text][fusion_text]

EV 1 EV 8
1 second at f1.4 1/60 second at f2
2 seconds at f2 1/30 second at f2.8
4 seconds at f2.8 1/15 second at f4
8 seconds at f4 1/8 second at f5.6
through to… through to…
64 seconds at f11. 1 second at f16

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Prontor Shutter with EV Scale

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Hasselblad C 80mm Planar Lens with EV

[/fusion_text][/one_half][fusion_text]Why do Hasselblad use EV?

500 series Hasselblad cameras do not have integrated light meters. When using a prism which contains an electronic light meter the photographer must manually set the camera to the desired exposure. As the shutter and aperture are controlled from the same location, the lens, it is sensible to set these at the same time. And the EV allows this to be done.[/fusion_text][one_half last=”no” spacing=”yes” center_content=”no” hide_on_mobile=”no” background_color=”” background_image=”” background_repeat=”no-repeat” background_position=”left top” border_position=”all” border_size=”0px” border_color=”” border_style=”” padding=”” margin_top=”” margin_bottom=”” animation_type=”” animation_direction=”” animation_speed=”0.1″ class=”” id=””][/one_half][one_half last=”yes” spacing=”yes” center_content=”no” hide_on_mobile=”no” background_color=”” background_image=”” background_repeat=”no-repeat” background_position=”left top” border_position=”all” border_size=”0px” border_color=”” border_style=”” padding=”” margin_top=”” margin_bottom=”” animation_type=”” animation_direction=”” animation_speed=”0.1″ class=”” id=””][/one_half][one_half last=”no” spacing=”yes” center_content=”no” hide_on_mobile=”no” background_color=”” background_image=”” background_repeat=”no-repeat” background_position=”left top” border_position=”all” border_size=”0px” border_color=”” border_style=”” padding=”” margin_top=”” margin_bottom=”” animation_type=”” animation_direction=”” animation_speed=”0.1″ class=”” id=””][/one_half][one_half last=”yes” spacing=”yes” center_content=”no” hide_on_mobile=”no” background_color=”” background_image=”” background_repeat=”no-repeat” background_position=”left top” border_position=”all” border_size=”0px” border_color=”” border_style=”” padding=”” margin_top=”” margin_bottom=”” animation_type=”” animation_direction=”” animation_speed=”0.1″ class=”” id=””][/one_half][fusion_text]What are the advantages of EV readings?

If your camera has a single physical location from where both the shutter speed and aperture can be controlled, but there is no light meter, then EV makes operation and control much simpler:

  • The light meter on a camera is easier to use. The photographer must transfer a single EV measurement from the light meter on the camera. Only having to remember single number, such as 14, is easier than remembering a series of shutter/aperture combinations.
  • Comparisons between two lights readings are simplified. Comparing the difference between EV 13 and 15 is easy: two stops. Whereas the difference between 1/250 @ f5.6and 1/60 @ f22 is not so straightforward; incidentally the answer is the exactly same – 2 stops.
  • Separation between determining the exposure and setting the shutter/aperture combination. When taking a photograph, you are automatically guided through a two step process. The different parts of the camera support the two separate decisions:

Step 1 – select part of the scene to take a light reading from, and, if appropriate, apply an exposure compensation. Set this light reading on the camera.

Step 2 – decide what depth of field, or shutter speed, would give you be best image

[/fusion_text][fusion_text]Why do 35mm and other cameras not use EV?

The primary advantages of using EV exist when a camera’s shutter and aperture are located together, and the light meter is somewhere else. In a fully manually controlled 35mm camera the aperture is controlled by the lens, and the shutter control is on the camera body: the shutter and aperture are disconnected; when one is changed the other is not automatically adjusted.

As cameras became more automated, the light meter would generally be added to the body and connected both the lens aperture and shutter. On a Rolleiflex and Nikon F Photomic both the shutter and aperture are physically connected to the light meter in the body/prism.[/fusion_text][one_half last=”no” spacing=”yes” center_content=”no” hide_on_mobile=”no” background_color=”” background_image=”” background_repeat=”no-repeat” background_position=”left top” border_position=”all” border_size=”0px” border_color=”” border_style=”” padding=”” margin_top=”” margin_bottom=”” animation_type=”” animation_direction=”” animation_speed=”0.1″ class=”” id=””][imageframe lightbox=”no” lightbox_image=”” style_type=”none” hover_type=”none” bordercolor=”” bordersize=”0px” borderradius=”0″ stylecolor=”” align=”center” link=”” linktarget=”_self” animation_type=”0″ animation_direction=”down” animation_speed=”0.1″ hide_on_mobile=”no” class=”” id=””] [/imageframe][/one_half][one_half last=”yes” spacing=”yes” center_content=”no” hide_on_mobile=”no” background_color=”” background_image=”” background_repeat=”no-repeat” background_position=”left top” border_position=”all” border_size=”0px” border_color=”” border_style=”” padding=”” margin_top=”” margin_bottom=”” animation_type=”” animation_direction=”” animation_speed=”0.1″ class=”” id=””][imageframe lightbox=”no” lightbox_image=”” style_type=”none” hover_type=”none” bordercolor=”” bordersize=”0px” borderradius=”0″ stylecolor=”” align=”none” link=”” linktarget=”_self” animation_type=”0″ animation_direction=”down” animation_speed=”0.1″ hide_on_mobile=”no” class=”” id=””] [/imageframe][/one_half][one_half last=”no” spacing=”yes” center_content=”no” hide_on_mobile=”no” background_color=”” background_image=”” background_repeat=”no-repeat” background_position=”left top” border_position=”all” border_size=”0px” border_color=”” border_style=”” padding=”” margin_top=”” margin_bottom=”” animation_type=”” animation_direction=”” animation_speed=”0.1″ class=”” id=””][fusion_text]

Rolleiflex Meter – setting the shutter and aperture
move the eye, so you locate it over the meter’s needle

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Nikon F Photomic – the meter is located in the prism, and
has direct couplings to both the shutter and aperture

[/fusion_text][/one_half][fusion_text]Does modern equipment have EV?

Yes, EV can still be found on modern photographic equipment. Hasseblad are most persistent in still having EV on their products, even a modern H system camera can display EV![/fusion_text][one_third last=”no” spacing=”yes” center_content=”no” hide_on_mobile=”no” background_color=”” background_image=”” background_repeat=”no-repeat” background_position=”left top” border_position=”all” border_size=”0px” border_color=”” border_style=”” padding=”” margin_top=”” margin_bottom=”” animation_type=”” animation_direction=”” animation_speed=”0.1″ class=”” id=””][imageframe lightbox=”no” lightbox_image=”” style_type=”none” hover_type=”none” bordercolor=”” bordersize=”0px” borderradius=”0″ stylecolor=”” align=”center” link=”” linktarget=”_self” animation_type=”0″ animation_direction=”down” animation_speed=”0.1″ hide_on_mobile=”no” class=”” id=””] [/imageframe][/one_third][one_third last=”no” spacing=”yes” center_content=”no” hide_on_mobile=”no” background_color=”” background_image=”” background_repeat=”no-repeat” background_position=”left top” border_position=”all” border_size=”0px” border_color=”” border_style=”” padding=”” margin_top=”” margin_bottom=”” animation_type=”” animation_direction=”” animation_speed=”0.1″ class=”” id=””][imageframe lightbox=”no” lightbox_image=”” style_type=”none” hover_type=”none” bordercolor=”” bordersize=”0px” borderradius=”0″ stylecolor=”” align=”center” link=”” linktarget=”_self” animation_type=”0″ animation_direction=”down” animation_speed=”0.1″ hide_on_mobile=”no” class=”” id=””] [/imageframe][/one_third][one_third last=”yes” spacing=”yes” center_content=”no” hide_on_mobile=”no” background_color=”” background_image=”” background_repeat=”no-repeat” background_position=”left top” border_position=”all” border_size=”0px” border_color=”” border_style=”” padding=”” margin_top=”” margin_bottom=”” animation_type=”” animation_direction=”” animation_speed=”0.1″ class=”” id=””][imageframe lightbox=”no” lightbox_image=”” style_type=”none” hover_type=”none” bordercolor=”” bordersize=”0px” borderradius=”0″ stylecolor=”” align=”center” link=”” linktarget=”_self” animation_type=”0″ animation_direction=”down” animation_speed=”0.1″ hide_on_mobile=”no” class=”” id=””] [/imageframe][/one_third][one_third last=”no” spacing=”yes” center_content=”no” hide_on_mobile=”no” background_color=”” background_image=”” background_repeat=”no-repeat” background_position=”left top” border_position=”all” border_size=”0px” border_color=”” border_style=”” padding=”” margin_top=”” margin_bottom=”” animation_type=”” animation_direction=”” animation_speed=”0.1″ class=”” id=””][fusion_text]

Sekonic Light Meter’s EV Display

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Hasselblad CB Lens’s EV Control

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Hasselblad H displays an EV value

[/fusion_text][/one_third][fusion_text]Technical Information

The chart below, from the wikipedia, shows different EV for aperture and shutter combinations:
– follow the red line for an EV, at any point on the red line read off using the horizontal and vertical scales to find the aperture and shutter
– the green lines show for two different lenses, what an automatic program mode would set as the aperture and shutter. The lower green line is for a fast 50mm f1.4 lens, and the upper is for a 24-85mmm f3.5 zoom lens[/fusion_text][imageframe lightbox=”no” lightbox_image=”” style_type=”none” hover_type=”none” bordercolor=”” bordersize=”0px” borderradius=”0″ stylecolor=”” align=”center” link=”” linktarget=”_self” animation_type=”0″ animation_direction=”down” animation_speed=”0.1″ hide_on_mobile=”no” class=”” id=””] [/imageframe][fusion_text]

EV Chart from https://upload.wikimedia.org/wikipedia/commons/d/d8/Exposure_program_chart.gif

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