Nikon N4004 Decision Master System Technical Guide

Introduction to the Nikon N4004

The Nikon N4004 autofocus SLR camera offers point-and-shoot simplicity combined with high-performance features, appealing to a broad market. Its advanced autofocus technology ensures accurate operation even in low light, with the option of manual focus for precise control. The camera supports various exposure modes, including program auto, shutter-priority auto, aperture-priority auto, and manual exposure, catering to both beginners and advanced photographers.

Key features include built-in auto TTL flash, an integrated motor drive, and compatibility with AF Nikkor lenses for full automation, as well as AI-type lenses for manual operation. Nikon's proprietary Decision Master System sets new standards for automatic and creative photography.

Target Audience

The N4004 is designed for:

• Amateurs seeking simple operation: Offers fully automatic program auto exposure and autofocus, with guidance for flash usage. Film loading, advancing, and rewinding are automated.
• More advanced photographers: Provides dual program auto, aperture-priority auto, shutter-priority auto, and manual control for creative flexibility.

Decision Master System

Nikon's Decision Master System integrates advanced camera and lens computers for comprehensive control. It automates complex techniques like exposure compensation and balanced fill-flash, making photography easier and more mistake-proof.

Core Components and Technologies:

• Advanced Autofocus: Features Nikon's AM200 sensor module with 200 CCDs, offering superior speed and precision, even in low light, detecting details difficult for the human eye. The system ensures the shutter releases only when focus is achieved.
• Triple-Sensor Light Metering: Divides the scene into three segments for measurement, computing optimal exposure values for various lighting conditions, including difficult ones.
• Built-in Auto TTL Flash: Provides convenient flash photography with automatic TTL control, ensuring accurate flash exposures. It supports balanced fill-flash, automatically adjusting flash output and camera settings to balance subject and background exposure.
• Dual Program Auto Exposure: Automatically adjusts shutter speed and aperture. It selects High-Speed Program for lenses 135mm and longer to prevent blur, or Normal Program for shorter lenses.
• Automatic Film Operation: Handles film loading, advance, and rewind automatically. Film speed is read from DX-coded films (ISO 25-5000) or defaults to ISO 100 for non-DX films.
• Creative Exposure Options: Offers aperture-priority auto, shutter-priority auto, and manual exposure modes, along with AE-lock for creative control.
• Shutter Speed Range: 1 second to 1/2000 second, plus Bulb (B).
• BriteView Focusing Screen: Enhances viewfinder brightness for better autofocus and manual focusing.
• Viewfinder Information: Displays essential shooting data using simple graphic symbols.
• Shutter Lock: Prevents accidental shots until focus and exposure are correct, or if settings are improper.
• Manual Focus Capability: Allows manual focusing with electronic confirmation in the viewfinder.
• AF Lens Interchangeability: Supports a wide range of AF Nikkor lenses for full automation and high-quality results. AI-type lenses can also be used for manual operation.
• Accessory Flash Compatibility: Supports dedicated Nikon speedlights (e.g., SB-20, SB-22) for enhanced flash capabilities.
• Power Source: Uses four AA-size batteries.

Superior Autofocus System

Building on Nikon's legacy (F3AF, N2020), the N4004's Decision Master System features the AM200 autofocus sensor module. This system offers:

• AM200 Sensor Design: A one-piece module for improved stability and accuracy.
• Low Light Sensitivity: Accurate autofocus detection down to EV 1 (depending on subject contrast).
• 200 CCDs: The largest number in an AF SLR at the time, ensuring precise focusing and detection of fine patterns.
• Slanted CCD Configuration: Facilitates faster intersection of curves and lines for improved focusing on minute patterns.
• Reduced Difficult Scenes: Autofocus works in most situations, excluding only contrast-less scenes.
• Improved Stability and Speed: The motor precisely stops at the focus point without inertia, and focusing is rapid.
• Specially Developed Software: Optimizes processing of data from the 200 CCDs.
• Total Autofocus Design: Integrates optical path, AM200 sensor, software, and gear train for outstanding performance.

The AM200 sensor module comprises an optical block and a CCD package. Light enters through a filter, converges at a focal point, diverges, and is reflected by a slanted surface. This light then converges via spherical surfaces onto two CCD line sensors (100 elements each), creating a duplicated image for comparison. The phase detection system analyzes the CCD output to control the AF motor, which moves the lens with precise 5-step force.

The BriteView focusing screen enhances light deflection to the autofocus sensor without compromising viewfinder image quality.

Triple-Sensor Light Metering

Nikon pioneered multi-pattern evaluative metering, and the N4004's Decision Master System extends this to available light and flash photography. The triple-sensor meter is designed for simplicity and automation.

• Optimal Exposure: Achieved through sophisticated computer software developed from extensive photo analysis.
• No Manual Compensation Needed: Handles difficult lighting conditions automatically.
• Subject Position Flexibility: Optimal exposure is achieved regardless of subject placement in the frame.
• Brightness Control: Automatically manages extreme brightness information for better exposure results.

The triple sensor, located above the eyepiece, has three segments and a lens. It measures brightness in the left, center, and right areas of the scene. The microcomputer processes these readings, disregarding extreme values, and classifies lighting conditions to compute an optimal exposure value using specific formulas. This system can classify scenes into center-weighted average, dim-light weighted, or averaged metering, based on brightness and contrast analysis, providing expert-level exposure automatically.

The system effectively handles challenging scenes like those with the sun in the picture or night scenes, providing balanced exposures where conventional center-weighted metering might fail.

Balanced Fill-Flash Capability

The N4004 features a built-in auto TTL flash and excels in fill-flash photography, a technique often difficult for users. The Decision Master System, utilizing the triple-sensor meter and TTL flash, ensures perfect, balanced exposures for both the subject and background, preventing wash-outs or dark areas. This professional technique is made automatic and accessible to beginners.

N4004 Flash Features Summary:

• Built-in flash is always available.
• Through-the-lens (TTL) automatic flash output control.
• Decision Master System recommends flash use for backlit subjects.
• Balanced fill-flash ensures accurate exposure for both subject and background.

Built-in Flash Specifications: Guide number 12 (ISO 100, meters), flash sync speed 1/100 sec., coverage 35mm, recycling time approx. 4.5 seconds.

Comparison to Conventional Methods:

• Centerweighted Metering (without flash): Subject often underexposed due to bright background.
• Manual Exposure Compensation: Can overexpose background if adjusted for the subject, leading to flat results.

The N4004's Total Light Control automatically manages lighting. If the scene is dark (EV10 or lower), it recommends flash. If the subject is backlit or the center sensor is darker than others, it recommends fill-flash. The system controls both background exposure and flash output automatically, classifying scenes by brightness and contrast to determine appropriate flash output levels (low, lower, lowest) and adjusting exposure based on background brightness.

Programmed Auto TTL Flash: In Program Auto mode, shutter speed is fixed at 1/100 sec. Aperture is set based on film ISO. For scenes EV10 or brighter, balanced fill-flash is used, selecting the best aperture for the background. For scenes darker than EV10, normal TTL auto flash is used, setting the aperture to match film ISO (e.g., f/2.8 for ISO 100 film with an f/1.8 lens).

Compatible AF Nikkor Lenses for Built-in Flash: AF Nikkor 50mm f/1.4, 50mm f/1.8, 180mm f/2.8 ED-IF, 300mm f/4 ED-IF, 28-85mm f/3.5-4.5 (35mm or longer), 35-70mm f/3.3-4.5, 35-105mm f/3.5-4.5, 35-135mm f/3.5-4.5, 70-210mm f/4, Micro 55mm f/2.8. Note: Avoid lens hoods to prevent vignetting. Some lenses may have limitations at minimum focusing distances.

Exposure Control Modes

The N4004 offers versatile exposure control via two ergonomic dials.

• Program Auto Exposure (A & S dials set): Automatically sets shutter speed and aperture. Features two program lines: Normal Program (for lenses < 135mm) and High-Speed Program (for lenses ≥ 135mm) to minimize camera shake. Both programs stop at EV15-2/3 (for ISO 100).
• Aperture-Priority Auto Exposure (Aperture dial set, Shutter dial at A): User sets aperture for depth-of-field control; camera sets shutter speed. Shutter speed selection is stepless.
• Shutter-Priority Auto Exposure (Shutter dial set, Aperture dial at S): User sets shutter speed for motion control; camera sets aperture. Aperture selection is stepless.
• AE Lock (AEL button): Overrides triple-sensor metering, activating center-weighted metering for creative control, allowing emphasis on specific parts of a scene.
• Manual Exposure Control: User selects both aperture and shutter speed. Viewfinder LEDs provide exposure guidance. Metering is center-weighted.

TTL Auto Flash Control: Operates with built-in or optional TTL speedlights. Selects balanced fill-flash for EV10 or brighter, and normal TTL auto flash for dimmer conditions. Optional speedlights include SB-20, SB-22, SB-15, SB-16B.

In Program Auto mode, shutter speed is 1/100 sec. In Shutter-Priority and Manual modes, if the dial is set to 1/125 sec. or faster, it defaults to 1/100 sec.; slower settings are retained. Aperture is controlled based on film ISO and lens maximum aperture.

Built-in Motor Drive and Film Handling

The N4004 simplifies film handling with its integrated motor drive:

• Loading: Insert film leader to the orange mark, close the back, and press the shutter release to automatically advance to frame 1.
• DX Indexing: Automatically reads film speed from DX-coded films (ISO 25-5000) or sets ISO 100 for non-DX films.
• Film Advance: Motor automatically advances film after each shot.
• Film End Detection: Automatically detects the end of the roll, indicated by a self-timer LED.
• Film Rewind: Automatic rewinding initiated by a simple lever-and-button operation, stopping automatically when complete.

Battery Life: Provides approximate number of 36-exposure rolls per set of fresh batteries (e.g., AA alkaline: ~50 rolls without flash, ~20 rolls with 50% flash at 20°C).

Viewfinder Information and Shutter Locks

The N4004 viewfinder, with its BriteView screen, provides clear shooting information:

• Autofocus Indicators: In-focus (green LED), front/rear focus, autofocus impossible.
• Auto Exposure Indicators: Auto exposure possible (high-speed shutter, slow-shutter warning), too bright, too dark.
• Manual Exposure Indicators: Correct exposure, over/under exposure warnings.
• AE Lock Indicator: Shows when AE lock is active.
• Bulb Mode Indicator: Shows when shutter is set to Bulb.
• Speedlight Indicators: Speedlight ready (green LED), full-power flash warning (red LED), recharging status, external speedlight status, speedlight wrong setting.
• Other Indicators: Self-timer setting, end of film.

Shutter Locks: The shutter release is locked until correct autofocus and automatic exposure are achieved. It also prevents mistakes from improper lens aperture settings or insufficient flash recharge.

Optional Speedlights

Optional Nikon TTL speedlights (SB-20, SB-22, SB-15, SB-16B) offer enhanced capabilities:

• Work with N4004's advanced flash controls (balanced fill-flash, programmed auto TTL).
• Provide higher power and range.
• SB-20 and SB-22 feature autofocus illuminators for low-light focusing.
• Flash heads tilt for bounce flash.
• Offer programmed TTL auto flash, non-TTL auto, and manual modes.

SB-22 Specifications:

• Guide Number: 25 (ISO 100, meters), 82 (ISO 100, feet).
• Flash Coverage: 28mm/35mm or longer.
• AF Assist LED: Provided.
• Power Source: Four AA batteries.
• Dimensions: 2.7x4.1x3.1 in.
• Weight: 8.8 oz. (without batteries).

SB-20 Specifications:

• Guide Number: 30 (ISO 100, meters), 98 (ISO 100, feet).
• Flash Coverage: 28mm/35mm/85mm or longer.
• AF Assist LED: Provided.
• Power Source: Four AA batteries.
• Dimensions: 2.8x4.3x2.7 in.
• Weight: 9.1 oz. (without batteries).

N4004 and Speedlight Operation Summary:

*Shutter speed setting of 1/125 or above is automatically disregarded and 1/100 is set. Slower shutter speed settings are respected.

Electronics and System Integration

The N4004's electronics are driven by a high-performance 8-bit microcomputer, managing functions like film speed setting, self-timer, AE lock, and communication with the lens CPU.

Block Diagram of N4004 Electronics: Depicts the interconnectedness of the microcomputer, autofocus sensor, motors, indicators, and other electronic components. Key elements include the CPU, AM200 sensor module, triple-sensor metering, TTL flash control, motor drive IC, and power components.

AF Nikkor with CPU: All AF Nikkor lenses feature a built-in CPU that communicates with the camera body via seven electronic contacts, exchanging data on lens specifications (minimum f/stop, focal length) and monitoring zoom settings.

Sensors and Control: The system utilizes triple-sensor metering and TTL flash control sensors. The CPU processes data from these sensors to control aperture, shutter speed, and flash output. A Lithium Niobate oscillator provides timing, and various ICs manage motor drives, signal amplification, and interface functions.

Lens Compatibility Table

The Nikon N4004 is designed to work optimally with AF Nikkor lenses. Current Nikon F-mount lenses (AI-type/Series E) can also be used for manual operation without TTL exposure metering.

When a non-AF Nikkor lens or an AF Nikkor for the Nikon F3AF is mounted on the N4004:

• Aperture is set by the lens's aperture ring; the camera's aperture dial is disregarded.
• Shutter speed is set on the N4004's shutter speed dial.
• Auto exposure modes are not operative; only manual exposure is available.
• There is no exposure information displayed in the viewfinder.
• In-focus position is confirmed electronically by a viewfinder LED.
• TTL automatic flash control is available with non-AF lenses. The user must use the flash sync speed on the shutter speed dial and the appropriate aperture on the lens.
• The TC-16A cannot be used with the N4004.

Nikon Imaging Technologies

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