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avantiindietro Pentax 645N: overview

In 1984, PENTAX first introduced the PENTAX 645, an epoch-making camera, to field photographers. Despite its medium-format design, it handled superbly and soon became the favorite of

Now PENTAX introduces the 645N, a new medium-format SLR that combines the proud tradition and technological excellence of the 645 with a host of new features, including a high-precision AUTOFOCUS system, to make it even more maneuverable and responsive in the field.

Pentax 645N rigid body  Pentax 645N electronics


The 645N incorporates the PENTAX-developed SAFOX IV phase-matching autofocus system to ensure accurate focusing not only on subjects with vertical orientation but also on those with horizontal orientation . - even under such poor lighting conditions as EV-1. The choice of the wider "3-Point AF" frame and the pinpoint "Spot AF" frame allows the photographer to use the most suitable focus frame for each subject and in every situation. The 645N offers three focus modes to choose from: "AF Single" activates the shutter only when the subject comes into focus; "AF Servo" lets the user release the shutter at any time. Manual Focus lets the user adjust the focus manually using the focus ring on the lens. In the manual-focus mode the focus indicator in the viewfinder provides the focus status. In the AF Servo mode, the 645N's AF system detects the subject's movement (toward or away from the camera) and "predicts" the optimum focusing point at shutter release for pinpoint focus on the subject on the move.

Data print

To keep accurate track of photographic data, the 645N lets the user imprint valuable data (exposure frame number, exposure mode, shutter speed, aperture, exposure compensation value, metering mode and lens focal length) at the bottom of the film just outside the image area.


The 645N incorporates a newly developed Dual Six-Segment multi-pattern metering system. Two sensors positioned at both sides of the viewfinder measure the subject's lighting condition in two different areas: the wide sensor covers the entire image field, while the narrow sensor monitors the light reaching the central area of the image field. As a result, the 645N can measure the subject's lighting condition with exceptional accuracy and efficiency. In addition to the Dual Six-Segment metering, the 645N also offers the pinpoint Spot Metering and conventional Center-Weighted Metering modes. The 645N's four distinctive exposure modes allow the user to react effortlessly and efficiently to every situation and create the desired visual effect with ease: Programmed AE for adjustment-free shooting; "Aperture-Priority AE" to emphasize the depth of field; "Shutter-Priority AE" for sports and action photography; and "Metered Manual" for maximum control over exposure settings.


A built-in motor drive advances the film at the speed of 2.0 frames per second. Thanks to the high-precision pulse-count film transport mechanism, the spacing between frames is identical and the number of frames which can be taken from one roll of film has been increased from the 645 (16 frames from 120 film and 33 frames from 220 film). This motor drive also offers two film advance modes: "Single Advance" to advance one frame for each shutter release and "Consecutive Advance" to successively advance the film as long as the shutter release button is depressed. In addition, the motor drive automatically loads the film and advances it to the first frame, and winds the film into the film holder to avoid accidental exposure during film changes.

Pentax 645N light path  Pentax 645N shutter

Viewfinder and panels

Pentax 645N viewfinder green LEDsThe 645N's viewfinder eyepiece comes equipped with a built-in diopter adjuster to adjust the viewfinder image for near- and far-sightedness within a range between -3.5 and +1 diopters. The 645N incorporates an acclaimed Natural-Bright-Matte focusing screen to provide a sharp, bright viewfinder image. In addition to the standard Center Spot Matte screen, the photographer can also select the AF Split-Image, AF Microprism or Cross-Lined Matte screen.Located at the camera's right shoulder, the LCD data panel provides the photographer with useful operational data at a glance in easy-to-understand letters, digits and symbols. An LCD data panel located at the bottom of the viewfinder indicates a full range of photographic data. Its bar-graph indicator is especially useful for checking exposure status in the metered Manual mode.

Rigid body

The 645N's body is made of rigid aluminum and protected with a glass-fiber-reinforced polycarbonate coating approximately 1.7 times thicker than a normal coating. As a result, the 645N is extremely durable and resistant to shock and wear. In addition, special mechanisms are incorporated in the 645N to ensure low-noise, low-shock operation - particularly important features in wildlife photography.

Other features

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  • With a single shutter release, the auto bracketing feature automatically takes three pictures of the same subject in the order of normal, under- and overexposure. The desired exposure level can be easily selected using the auto bracketing lever.
  • The exposure compensation feature allows the photographer to make minute exposure adjustments with ease in 1/3 steps within a range of +/-3EV.
  • Memorize the subject's lighting condition for 10 seconds with a single push of the memory lock button, which allows photographers to re-compose the image freely without changing the exposure level on the most important element of the picture.
  • The 645N uses exclusive film holders compatible with those of the 645. So, by carrying several film holders loaded with film, the photographer can save a considerable amount of time for film changes.
  • The depth-of-field preview function allows the photographer to check the depth-of-field before taking a picture, thus making it possible to create the desired visual effect without failure.
  • Multi-Exposure enables the photographer to produce a unique, eye-catching image by making the desired number of exposures on a single frame.
  • The 645N's battery holder takes six AA-size batteries. In addition to alkaline batteries, lithium batteries, which offer a longer battery life and a stable power supply at low temperatures, can also be used.
  • The built-in self-timer delays shutter release by 12 seconds, allowing the photographer to become part of memorable pictures.


Pentax 645N operating parts




For citation purposes
Gian Luca Agnoli, PHOTOGRAPHY, URL: