Electronic viewfinder
Encyclopedia
An electronic viewfinder or EVF is a viewfinder
where the image captured by the lens is projected electronically onto a miniature display. The image on this display is used to assist in aiming the camera at the scene to be photographed.
. Electronic viewfinders in digital still camera
s are very similar to those in video camera
s.
Electronic viewfinders have the following limitations (2007):
Electronic viewfinders have been in use with bridge cameras for some years, and later entered the field of compact cameras (with the Ricoh
GX100) and of cameras such as the micro four thirds camera Panasonic
DMC-G1 or the newer Nikon 1
V1
, which are not actually DSLR, but have interchangeable lenses, and electronic viewfinder in place of an optical one.
Many professional photographers and advanced amateurs prefer digital single-lens reflex
cameras which have a true optical through-the-lens viewfinder (OVF). From 2006 some digital SLR camera models provide both through-the-lens
viewing and a "live preview" on the LCD display (as distinct from an electronic viewfinder). These include the Olympus
E-330
, E-410
, E-510
and E-3
, the Panasonic Lumix DMC-L1
and DMC-L10
, the Leica Digilux 3
, the Canon EOS 40D
, EOS 50D
, EOS 60D
, EOS 7D
and EOS-1D Mark III
, and the Nikon
D3
, D300
and D90
.
Viewfinder
In photography, a viewfinder is what the photographer looks through to compose, and in many cases to focus, the picture. Most viewfinders are separate, and suffer parallax, while the single-lens reflex camera lets the viewfinder use the main optical system. Viewfinders are used in many cameras of...
where the image captured by the lens is projected electronically onto a miniature display. The image on this display is used to assist in aiming the camera at the scene to be photographed.
Operation
The sensor records the view through the lens, the view is processed, and finally projected on a miniature display which is viewable through the eyepieceEyepiece
An eyepiece, or ocular lens, is a type of lens that is attached to a variety of optical devices such as telescopes and microscopes. It is so named because it is usually the lens that is closest to the eye when someone looks through the device. The objective lens or mirror collects light and brings...
. Electronic viewfinders in digital still camera
Still camera
A still camera is a type of camera used to take photographs. Traditional cameras capture light onto photographic film. Digital cameras use electronics, usually a charge coupled device to store digital images in computer memory inside the camera...
s are very similar to those in video camera
Video camera
A video camera is a camera used for electronic motion picture acquisition, initially developed by the television industry but now common in other applications as well. The earliest video cameras were those of John Logie Baird, based on the electromechanical Nipkow disk and used by the BBC in...
s.
Electronic viewfinders in still photography
Electronic viewfinders have the following advantages over optical viewfinders:- Lack of parallaxParallaxParallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight, and is measured by the angle or semi-angle of inclination between those two lines. The term is derived from the Greek παράλλαξις , meaning "alteration"...
and ability to cope with high zoom-ratio lenses, without the need for a bulky reflex mirrorSingle-lens reflex cameraA single-lens reflex camera is a camera that typically uses a semi-automatic moving mirror system that permits the photographer to see exactly what will be captured by the film or digital imaging system, as opposed to pre-SLR cameras where the view through the viewfinder could be significantly...
. Cameras with a separate optical viewfinder show the scene from a different viewpoint than that of the camera lens. - Information about the scene, such as a histogramImage histogramAn image histogram is a type of histogram that acts as a graphical representation of the tonal distribution in a digital image. It plots the number of pixels for each tonal value. By looking at the histogram for a specific image a viewer will be able to judge the entire tonal distribution at a...
, can be overlaid with the scene. - EVFs can show approximately how the scene will look like under the chosen exposure.
- EVFs can show a low-light scene brighter than it is when they are display-priority.
- Most EVFs show 100% coverage of the final image.
- EVFs provide a more accurate depiction of the contrast and tonal qualities that will appear in the final image.
Electronic viewfinders have the following limitations (2007):
- There may be a noticeable lag between the changes in the scene and the electronic viewfinder display.
- The resolutionDisplay resolutionThe display resolution of a digital television or display device is the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is controlled by all different factors in cathode ray tube , flat panel or projection...
of the display may be too low to allow for accurate manual focusingFocusingIn psychotherapy-related disciples, the term focusing is used to refer to the simple matter of holding a kind of open, non-judging attention to something which is directly experienced but is not yet in words. Focusing can be used to become clear on what one feels or wants...
. Some cameras assist in this by magnifying the center of the image or by outlining the edges of in-focus objects; even with this adaptation, manual focus using an EVF is more difficult than using a DSLR optical viewfinder. - A very few EVFs do not have automatic gain control and become virtually blank in low-light conditions.
- An EVF has high power consumption, usually comparable to the main LCD screen. For saving battery, PanasonicPanasonicPanasonic is an international brand name for Japanese electric products manufacturer Panasonic Corporation, which was formerly known as Matsushita Electric Industrial Co., Ltd...
Lumix G1 and G2 both have automatic eye sensors which switch the display from the rear LCD to the EVF when we put the EVF to our eye. Whereas Panasonic Lumix G10 has a button to switch the display.
Electronic viewfinders have been in use with bridge cameras for some years, and later entered the field of compact cameras (with the Ricoh
Ricoh
or Ricoh, is a Japanese company that was established in 1936 on February 6th, as , a company in the RIKEN zaibatsu. Its headquarters is located in Ricoh Building in Chūō, Tokyo....
GX100) and of cameras such as the micro four thirds camera Panasonic
Panasonic
Panasonic is an international brand name for Japanese electric products manufacturer Panasonic Corporation, which was formerly known as Matsushita Electric Industrial Co., Ltd...
DMC-G1 or the newer Nikon 1
Nikon 1 series
The Nikon 1 series are high-speed mirrorless interchangeable-lens cameras. Announced on 21 September 2011, Nikon claims that it is "Nikon's most significant announcement since we introduced our first digital camera 14 years ago"...
V1
Nikon 1 V1
The Nikon 1 V1 is a Nikon 1 series mirrorless interchangeable-lens camera launched by Nikon on 21 September 2011....
, which are not actually DSLR, but have interchangeable lenses, and electronic viewfinder in place of an optical one.
Many professional photographers and advanced amateurs prefer digital single-lens reflex
Single-lens reflex camera
A single-lens reflex camera is a camera that typically uses a semi-automatic moving mirror system that permits the photographer to see exactly what will be captured by the film or digital imaging system, as opposed to pre-SLR cameras where the view through the viewfinder could be significantly...
cameras which have a true optical through-the-lens viewfinder (OVF). From 2006 some digital SLR camera models provide both through-the-lens
Through-the-lens
Through-the-lens metering is a photographic term describing a feature of cameras capable of measuring light levels in a scene through their taking lenses, as opposed to a separate metering window...
viewing and a "live preview" on the LCD display (as distinct from an electronic viewfinder). These include the Olympus
Olympus Corporation
is a Japan-based manufacturer of optics and reprography products. Olympus was established on 12 October 1919, initially specializing in microscope and thermometer businesses. Its global headquarters are in Shinjuku, Tokyo, Japan, while its USA operations are based in Center Valley, Pennsylvania,...
E-330
Olympus E-330
The Olympus E-330 is a DSLR launched on 30 January 2006, using the Four Thirds System lens mount standard. Its main feature is its live image preview functionality, permitting an image to be previewed on the LCD screen. While live image preview is not new in compact digital cameras, the E-330 is...
, E-410
Olympus E-410
The Olympus E-410 is a 10 megapixel digital single-lens reflex camera intended be the smallest and lightest DSLR on the market...
, E-510
Olympus E-510
The Olympus E-510 is a 10 megapixel digital single-lens reflex camera oriented to the "prosumer" or "hobbyist" market. Announced in March 2007 to succeed the E-500, it represents the first use of the new Panasonic MOS sensors instead of the Kodak CCD sensors that Olympus had used previously...
and E-3
Olympus E-3
The Olympus E-3 was until 2011 Olympus Corporation's previous flagship camera, positioned as a professional DSLR camera. It is the successor to the Olympus E-1, which was launched in November 2003. The E-3, originally codenamed Olympus E-P1, was announced on 17 October 2007. The E-3, like the other...
, the Panasonic Lumix DMC-L1
Panasonic Lumix DMC-L1
The Lumix DMC-L1 was Panasonic's first digital single-lens reflex camera, and was announced in February 2006. This camera adheres to the Four Thirds System lens mount standard, making it the first non-Olympus Four Thirds camera, and thus confirming that the Four Thirds System is a semi-open...
and DMC-L10
Panasonic Lumix DMC-L10
The Lumix DMC-L10 is Panasonic's second digital single-lens reflex camera , a follow-up to the previous Lumix DMC-L1 model. It was announced in August 2007, and, like the Lumix DMC-L1, this model uses the Four Thirds System lens mount standard and contains some basic parts provided by Olympus...
, the Leica Digilux 3
Leica Digilux 3
The Digilux 3 is a digital single-lens reflex camera introduced by Leica on 14 September 2006. The Digilux 3 and the Panasonic Lumix DMC-L1 are identical cameras, using the Four Thirds standard lens mount and featuring a 7.5 Megapixels live view N-MOS sensor, but the Digilux 3 has improved firmware...
, the Canon EOS 40D
Canon EOS 40D
The Canon EOS 40D is a 10.1-megapixel semi-professional digital single-lens reflex camera. It was initially announced on August 20, 2007 and was released at the end of that month. It is the successor of the Canon EOS 30D, and is succeeded by the EOS 50D. It can accept EF and EF-S lenses...
, EOS 50D
Canon EOS 50D
The Canon EOS 50D is a 15.1-megapixel digital single-lens reflex camera. It is part of the Canon EOS line of cameras and succeeds the EOS 40D. In turn, it has been succeeded by the EOS 60D....
, EOS 60D
Canon EOS 60D
The Canon EOS 60D is a digital single-lens reflex camera from Canon. It is part of the Canon EOS line of cameras and succeeds the EOS 50D. It was publicly announced on August 26, 2010....
, EOS 7D
Canon EOS 7D
The Canon EOS 7D is an 18.0 effective megapixel APS-C crop CMOS digital single-lens reflex camera made by Canon. It was announced on September 1, 2009...
and EOS-1D Mark III
Canon EOS-1D Mark III
The EOS 1D Mark III is a professional 10.1 megapixel digital single lens reflex camera camera body produced by Canon. The EOS 1D Mark III was announced on February 21, 2007 and is the successor of the Canon EOS-1D Mark II N and was first released in May 2007...
, and the Nikon
Nikon
, also known as just Nikon, is a multinational corporation headquartered in Tokyo, Japan, specializing in optics and imaging. Its products include cameras, binoculars, microscopes, measurement instruments, and the steppers used in the photolithography steps of semiconductor fabrication, of which...
D3
Nikon D3
The Nikon D3 is a 12.1 megapixel professional grade full frame digital single lens reflex camera announced by the Nikon Corporation on 23 August 2007 along with the Nikon D300 DX format camera. The D3, along with the Nikon D3X, was a flagship model in Nikon's line of DSLRs, superseding the D2Hs...
, D300
Nikon D300
The Nikon D300 is a 12.3-megapixel professional DX format digital single-lens reflex camera that Nikon Corporation announced on 23 August 2007 along with the Nikon D3 FX format camera. It replaced the D200 as Nikon's DX format flagship DSLR...
and D90
Nikon D90
The Nikon D90 is a 12.3 megapixel digital single-lens reflex camera model announced by Nikon on August 27, 2008. It is a prosumer model that replaces the Nikon D80, fitting between the company's entry-level and professional DSLR models. Nikon gives the D90's Estimated Selling Price in the U.S...
.