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Pentaprism

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Pentaprism
A multi sided glass prism housed in the roof of an single-lens reflex camera so that the image that's seen be the lens can be viewed through an optical viewfinder above the lens. The light enters through the lens is reflected up by a reflex mirror to the prism and across to the eye.


Pentaprism
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Pentaprism
Edit Read more: Camera parts, Focusing system
Edited by Awcam
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A pentaprism is a five-sided reflecting prism used to deviate a beam of light by a constant 90, even if the entry beam is not at 90 to the prism.

Pentaprism
Techniques Glossary Pentaprism
A multi sided glass prism housed in the roof of an single-lens reflex camera so that the image that's seen be the lens can be viewed through an optical viewfinder above the lens.

~
Optical device, found on SLR cameras, which corrects the image (reversed by the lens), allowing eye-level viewing and focusing via the viewfinder.
(see Finder, Focusing screen, & SLR )
Perspective control lens
(see Shift) ...

~
The prism that sits on the top of most SLRs. The pentaprism transmits the light reflected upward by the camera's mirror into the camera's eyepiece.

~ Optical Viewfinder for 100% FOV and .95 magnification
Low profile glass pentaprism viewfinder, with interchangeable focusing screens, achieves a 100% optical field of view for framing accuracy in a highly compact form factor.
Magnesium alloy body w stainless steel chassis ...

~ - Five-sided prism in SLR cameras that renders a correctly-oriented view of the focusing screen.
PERSPECTIVE - Technique of depicting volumes and spacial relationships (a scene in three-dimensions) on a flat surface (an image having two dimensions).

-~ - optical device, usually fitted on 35mm cameras, which makes it possible to view the image while focusing. A mirror device laterally reverses the image so that the scene is viewed through the camera upright and the right way round.

~ (brighter)
So which camera is better depends, as always, on your needs. The consumer series cameras are inexpensive lightweight cameras and an excellent value for beginners and people on a budget.

A ~ distinguishes the D7000 from it's lower-end cousins the D3100 and D5000, which use pentamirror viewfinders. Pentaprisms are heavier, and add to the cost of the camera, but offer a brighter viewfinder image.

With a pentaprism providing 100 percent coverage the D7100 provides a bigger, brighter view through the viewfinder than the penta-mirror system of the D5200 with 95 percent coverage. It also has a bigger 3.

The camera uses a pentaprism like other digital SLRs to reflect the image entering the lens up to the viewfinder.
When you look through the viewfinder of the E-330, you see exactly what the lens sees, one of the advantages of a digital SLR camera.

html" } , { "Title" : "Focusing Screen" ,"GlossaryIcon" : "" ,"HideInGlossary" : "" ,"Summary" : "An element between the mirror and pentaprism or pentamirror in a single-lens-reflex camera. The mirror reflects the image from the lens upward onto the screen.

1949: East German Zeiss develops the Contax S, first SLR with an unreversed image in a pentaprism viewfinder
1955: Edward Steichen curates Family of Man exhibit at New York's Museum of Modern Art
1959: Nikon F introduced.

adjacent to the pentaprism
at the base of the lens mount
and many other places, depending on designer's will Usually, there is at least one silicon photo-diode.

It has three main elements: a hinged mirror, a matte focusing screen, and a five-sided glass prism called a pentaprism The mirror, in the viewing position, is below the viewing screen and behind the lens.

Usually rest around the pentaprism of the camera (but some were designed around the film rewind knob). It has an electrical contact which mated with a contact in the mounting foot of the flash unit.

The D7000 features a pentaprism viewfinder.
The body is compatible with the older AF and non-AF, AI lenses. So it has many non-CPU lenses that can be locked in-including my old favorites like the 55mm macro and 85mm fast telephoto.

The optical viewfinder uses a fixed pentaprism to provide TTL viewing (96 percent coverage) and metering.

Better SLRs use a solid glass prism (pentaprism) to direct the light path to the eyepiece. Some SLRs use a hollow box lined with mirrors (pentamirror), which saves some weight and bulk as well as cost. Although pentamirrors used to be dimmer than pentaprisms, this is no longer a hard rule.

Cameras with a pentaprism (as opposed to pentamirror) ensure that little light is lost before it hits your eye, however these often increase the cost of the camera significantly. Larger format sensors also produce a brighter viewfinder image (such as full frame 35 mm, compared to 1.5-1.

The penta mirror is an optical component equivalent to a pentaprism, of considerably reduced weight achieved by replacing a glass prism block with a combination of several mirrors.

There is a pentaprism in there, a five sided mirrored glass element that turns the light right side up and not backwards by reflecting the light with the camera mirror and the pentaprism. These 3 reflections turn the image so when we look through the viewfinder we see things as we normally do.

Today, with the availability of high resolution display screens, the use of a mirror, pentaprism/pentamirror and viewfinder is obsolete.

The photographer views the viewfinder screen through a pentaprism that makes the image eye-level and so that it appears right-side-up and not reversed.

A major difference between basic compact cameras and Digital Slr cameras is that Digital Slr cameras use a
mirror and pentaprism system to reflect the light coming through the lens directly to the eye level viewfinder.

Initially, the things that separated mid-range from entry-level DSLRs were a PC outlet to accommodate studio flash, a faster burst rate (usually more than 3fps), a higher-resolution LCD monitor, and a pentaprism viewfinder instead of a pentamirror finder.

Part of the space savings in these cameras comes from the removal of the mirror and the mechanical mechanisms that actuate that mirror. The iconic pentaprism on the top of an SLR can disappear and the body can get thinner and lighter because they eliminate the need to make room for a piece of glass ...

Light entering the camera through the lens is reflected up by a mirror behind the lens onto a ground glass screen above. This screen is viewed through the viewfinder and a glass pentaprism which turns the image the correct way up.

The advantages include smaller, lighter bodies with fewer moving parts (there's no need for the mirror or ~ used by SLRs) and full-time live view. This makes them easier to understand for users migrating up from a compact digital camera.

EVIL (Electronic Viewfinder Interchangeable Lens): EVIL is a term widely used to describe a type of digital, interchangeable-lens camera that, unlike a conventional single lens reflex camera, does not use a mirror system and ~ to direct light from the lens to an optical viewfinder.

That light is sent from the ~ into the viewfinder, allowing you to see what you are taking a picture of. When you press the shutter down, the mirror flips, allowing the light to go through the shutter onto the sensor for the amount of time set by the shutter speed.

Subsequent accessory shoes have been built as part of the camera and usually reat on top of the camera's ~; others are separate items that you mount on the camera body when you need them.

2 megapixel DX sensor, 39-point AF system, Expeed 2 image processor, ISO up to 25,600, magnesium alloy body, 2,016-pixel RGB metering sensor, 1080/24p video recording, 6 fps burst shooting, dual SD slots, and 100%, glass ~ viewfinder
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See also: See also: What is the meaning of Prism, Camera, Light, Finder, Image?

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