User:Bellabellab/pentaxlx

(DRAFT PAGE FOR Pentax LX, CONTAINS INCOMPLETE MAJOR CHANGES)

The Pentax LX is a 35 mm single-lens reflex camera produced by Pentax in Japan. It was introduced in 1980, to commemorate the 60th anniversary of Asahi Optical, and was produced until 2001. The LX uses the K mount, which is the Pentax proprietary bayonet lens mount, and has manual and aperture priority automatic exposure modes. It is the top-of-the-line professional, or "system", camera in the Pentax manual focus range, and has a large body of accessories. Compared with contemporary professional camera bodies from rival manufacturers, like the Canon New F-1 or Nikon F3, the LX body is smaller and lighter, weighing in at 570 g with its standard FA-1 finder.

Construction and features
The camera's construction is strong and durable, with a solid cast metal frame and metal covering plates. All buttons and dials are weather and dust sealed, a unique feature not found on other professional cameras of the day. This weather-sealing made it suitable for photography in mechanically-difficult coastal environments with salt in the air. Underneath the satin black finish is black chrome, so the underlying metal would not look brassy as the surface finish inevitably wore through in hard professional use. Both the viewfinder and the focusing screen are interchangeable to suit the task at hand, with a large choice of alternatives available.

The camera has an uncommon frame counter, being able to keep track of the frame number in either direction, whether advancing or rewinding the film. This feature dramatically adds to the flexibility of the camera, as well as aiding in taking multiple exposures. The front of the camera has a multi-function lever that allows mirror lock-up and depth of field preview, and acts as the camera's self-timer. The film take-up spool is of the "Magic-Needles" type, as found on the Pentax M Series cameras, which simplified loading.

These features made the LX highly sought-after among professionals both during and after production, with prices on e-commerce sites like E-bay in the range of $200 to $400.

Shutter and metering
The shutter and metering systems are very sophisticated, as much or more than any other camera of its time. The titanium shutter curtains are horizontally running with a flash synchronization ('X') speed of 1/75 second. The film speed dial can be set from 6 to 3200 ASA, and co-axially is an exposure compensation dial, which operates in 1/3 EV steps. When compensation mode is active, a small flag appears in the viewfinder to remind the user of the change from normal. The LX uses dynamic, off-the-film-plane TTL metering called Integrated Direct Metering (IDM).

Pre-release exposure information is obtained from light passing through a semi-silvered area of the mirror and then reflected down by a small secondary mirror to a metering cell in the base of the camera. From this, the user is given a shutter speed prediction by means of a vertical row of LEDs in the viewfinder. In auto mode, once the shutter is released, the light reflected from the first shutter curtain and the film continues to be measured by the same photocell as the exposure takes place, and is used to adjust the exposure time even if the subject light level is varying. The exposure metering has a range from EV1 to EV19 for manual exposure and an EV-6.5 to EV20 in automatic, in which exposures can be up to 125 seconds, making the camera excellent for available light photography.

In the manual mode, the predicted shutter speed is still displayed in the viewfinder as a recommendation, allowing the user to choose the speed indicated by aligning the translucent blue flag along the LED row, in addition to being able to select any other speed. The shutter is controlled mechanically at flash sync speed and all speeds above it, and electronically for all speeds below it. The whole upper range of speeds, including the flash sync speed, is therefore available without batteries in the camera.

Because the metering is entirely within the body of the camera, it functions fully with any of the interchangeable viewfinders, or even without one. The system also removes any necessity for a viewfinder window blind. The lens aperture is visible in the finder via a small window within the principle ones of the six viewfinders.

TTL flash control is also available using Pentax and certain third party dedicated units in the hot shoe (e.g. the Pentax AF280T), which are controlled by the camera taking measurements from the IDM during the exposure. The TTL capabilities are extended to dedicated external flash units (such as the Pentax AF400T hammerhead unit) via a special lead which connects to the conventional PC socket and additional contacts adjacent to it. The hot shoe and PC socket can also be used with non-dedicated flash units.

Interchangeable accessories
A number of professional accessories were made available for the LX, in addition to the conventional hot shoe flashes and motor drive:

Viewfinders
The LX has six unique interchangeable viewfinders, each designed for different use cases. These include:
 * The standard FA-1 eye-level pentaprism finder, which has a hot shoe and built-in adjustable diopter correction from 0 to 1.5 for users with corrective lenses. The aperture f-stop is visible at the top of the finder window.
 * The FA-1W eye-level pentaprism finder; the same as the FA-1, but with a diopter correction range of 1 to 3.
 * The FA-2 eye-level pentaprism finder intended to be compact and lightweight; the same as the FA-1, but without the hot shoe or the f-stop window.
 * The FE-1 waist-level "Magni-Finder" intended for close-up photography or situations where magnification is needed for accurate focusing. The f-stop is not visible through the viewfinder, and it has no hot shoe.
 * The FF-1 waist-level finder can fold to be almost flat when not in use. There is no hot shoe, and the aperture f-stop is not visible.
 * The FB-1 system finder base, which is used with any of three separate bayonet-mounted eyepieces:
 * The FC-1 action eyepiece, which can rotate 180° to provide either an eye-level view with a high eyepoint or a waist-level view.
 * The FD-1 "Magni-Eyepiece" which magnifies the view through the lens at a 45° viewing angle. The eyepiece features a diopter correction range of -4.5 to +3.5.
 * The FD-2 standard eyepiece, which has a 45° viewing angle, ideal for microscopy. Aperture f-stop is not visible in the viewfinder.

To switch viewfinders, a small lever is pushed to release the current one, allowing it to be removed and replaced with another. The task of changing can be performed with one hand. Both the LX and the Canon New F-1 use a more secure rail system to attach viewfinders, as opposed to the Nikon F3's dual latch system.

Focusing screens
[insert photo or diagram of SC-1 screen]

The LX has a total of 17 focusing screens (originally 9 with the early model ) that are specially coated to appear brighter than the screens in other cameras. The 9 focusing screens designed for the earlier Pentax MX system can also be used in the LX, as they have the same dimensions, though are not as bright. To switch focusing screens, a small "pincette", supplied with each new screen, is used to remove the current one from the focusing screen frame through the lens mount, and then to insert the new screen in its place.

The original 9 screens include:
 * The standard SC-21 ground-glass focusing screen with a split-image and microprism collar center.
 * SA-21, a simplified version of the SC-21 with only the microprism center (without the split-image component).
 * SA-23, similar to the SA-21, but modified to aid in focusing high-speed lenses (lenses with maximum apertures wider than ).
 * SB-21, a simplified version of the SC-21 without the microprism collar.
 * SD-21 all-matte focusing screen with crosshairs in the center, intended for astrophotography and macrophotography.
 * SD-11, similar to the SD-21 but with a clear background.
 * SE-20 all-matte focusing screen intended for use with macro and telephoto lenses.
 * SG-20, similar to the SE-20 but with an etched 6mm grid pattern intended for aligning architectural subjects or multiple exposure composition.
 * SI-20, similar to the SE-20 but with an engraved axial scale intended for determining subject size in microscope and bellows photography.

Five screens were added in the late model, most of which were variations of previous screens redesigned for long telephoto lenses:
 * SA-26, similar to the SA-23, but designed for lenses with focal lengths greater than 300mm.
 * SA-32 all-microprism field screen with finer microprism center.
 * SA-37, similar to the SA-32, but intended for use with telephoto lenses or close-up photography.
 * SC-26, similar to the SC-21, but designed for lenses with focal lengths greater than 300mm.
 * SE-25, similar to the SE-20, but designed for lenses with focal lengths greater than 300mm.

Three additional focusing screens were added for the limited release of the LX 2000, which were about 1/6 EV brighter than original LX screens:
 * SC-69, the same as the late-model SC-26.
 * SE-60 plain all-matte field screen designed for use with mirror lenses and Pentax "Star" lenses.
 * SG-60 all-matte field screen with a grid, designed for use with mirror lenses and Pentax "Star" lenses.

Detachable back
The standard camera back is detachable and interchangeable with two data backs, one of which, the Dial Data LX superimposes up to three characters chosen by the user in a corner of the frame, and the other, the Watch Data LX, superimposes a tiny analog clockface in the corner of the frame. For use with the Watch Data LX was a small film blind behind the shutter that could be raised to block light from the corner of the film where the clockface would be superimposed. Also taking advantage of the removable back is a high-capacity magazine allowing for 250 exposures.

Other accessories
To attach a camera strap, separate strap fasteners could be mounted to any two of the three accessory lugs on the front of the camera body, allowing the LX to be carried either horizontally or vertically, such as when a grip occupies the righthand accessory lug. Two right-handed grips were produced, Accessory Grip A, which was made to be whittled down to suit a photographer's exact needs, and Acessory Grip B, which was hand-contoured. Either grip could be attached to the camera by using a nickel or a screwdriver to tighten a screw.

Variations and special releases
The Pentax LX body was updated at least three times during its 20-year production, with a key variation being in the design of the shutter button lock switch. No link between exact serial numbers and design variations has been found, so the years of the updates are unknown.

In October 1981, Pentax made available 300 limited edition Pentax LX Gold cameras to celebrate having produced 10 million SLR cameras, the first camera manufacturer to reach that milestone according to the accompanying certificate. The camera and its SMC 1:1.2 50 mm lens are partly plated in 24-karat and partly covered in brown reptile skin, while some details are made of brown plastic, and it came with a brown Eveready Case. Cameras for some markets such as the U.S. have brown leather instead of reptile skin supposedly due to import laws. The actual number of cameras made is somewhat higher than 300 since a few were retained at Pentax reserved for their own use. The actual number for sale however was 300 cameras according to Pentax in Tokyo.

The Pentax LX Titanium was produced in 1994 in a limited edition of 1000 titanium-plated cameras to mark the company's 75th anniversary. Another Pentax LX Titanium was launched in 1996 in a limited number of 300, finished in black and carrying the inscription "Titanium".

The Pentax LX 2000 with an SMC Pentax-A 50mm ƒ/1.2 lens in bright metal finish marked the new millennium in the year 2000.