The Pentax 645NII is a medium-format SLR film camera that was introduced in 2001 as an upgrade to the Pentax 645N. It is part of the Pentax 645 system and is designed for 120/220 roll film, producing 6×4.5 cm negatives. The camera is highly regarded for its robust build, user-friendly ergonomics, and automation features, making it a favorite among professional and advanced amateur photographers.
I use the Pentax 645NII for the majority of my wild horse, nature, and landscape photography. It is a challenging and exhilarating adventure that I love.
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Key Features of the Pentax 645NII
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Film Format & Lens Mount
- Uses 120 or 220 roll film, capturing 15 (120) or 30 (220) exposures per roll.
- Uses the Pentax 645AF mount, compatible with Pentax 645 manual-focus and autofocus lenses.
- Can also use Pentax 67 lenses with an adapter.
Autofocus & Metering
- Features TTL phase-matching autofocus (single and continuous AF modes).
- Manual focus mode is available with a bright, easy-to-focus viewfinder.
- 6-segment, center-weighted, and spot metering modes for exposure control.
Shutter & Exposure Control
- Vertical-travel electronically controlled shutter with speeds from 15 sec to 1/1000 sec, plus Bulb mode.
- Automatic, Aperture-Priority, Shutter-Priority, and Manual exposure modes.
- Exposure compensation: ±3 stops in 1/3-stop increments.
Film Handling & Motor Drive
- Automatic film loading, advance, and rewind.
- Shoots at 2 frames per second in continuous mode.
- Mid-roll rewind option.
Viewfinder & Display
- Large, bright pentaprism viewfinder with 95% coverage.
- LED display inside the viewfinder showing essential settings (shutter speed, aperture, exposure compensation).
- LCD panel on the top plate for quick access to settings.
Flash & Connectivity
- Hot shoe and PC sync port for external flashes.
- Flash sync speed: 1/60 sec.
- Compatible with Pentax 645 dedicated flash units.
Build & Ergonomics
- Durable, weather-resistant polycarbonate and metal construction.
- Well-balanced grip, making it easier to handhold compared to bulkier medium format cameras.
- Weighs approximately 1.4 kg (3.1 lbs) without lens.
Power & Battery
- Powered by 6 AA batteries or an optional external power pack.
Pentax 645NII & Wild Horse Photography
A few years ago, I shared that I strive to use my Pentax 645N II camera system as much as possible for wild horse photography. It is an incredibly challenging endeavor, and my “keeper rate” is not exceptionally high, but I love pushing myself to new levels and earning my images. When everything comes together, the resulting prints are profoundly emotional and convey the precise ideas and intentions I work so diligently to achieve.
The first print I share above captures a stallion standing near the river on a cold and dark winter morning—a moment etched in my memory forever. At the time of this exposure, I had been following this stallion for nearly five years, yet I had never been able to get close enough to create an image like this. This photograph is among my best prints, as it powerfully conveys his strong and bold physical presence while showcasing the dramatic environment that defines his world.
The Pentax 645NII camera system is ideal for my wild horse photography due to its exceptional balance of image quality, portability, and functionality. Its medium-format film delivers outstanding detail and dynamic range. Its lightweight design and built-in features, such as autofocus and a light meter, enable quick, efficient shooting in dynamic, unpredictable environments. With the ability to use versatile telephoto lenses and shoot multiple exposures per roll, the 645NII streamlines the workflow compared to larger formats, allowing you to focus on capturing the beauty and spontaneity of wild horses in the field.
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645 film (56 x 41.5mm) has 2.6 times the area of full-frame 35mm (36 x 24mm), or a 0.62 crop factor.
I am using the following lenses for my wild horse photography:
- SMC Pentax FA* 300mm F4 ED [IF] (~180mm) (most used lens for wild horse portraits)
- SMX Pentax FA 200mm F4 [IF] (~125mm) (recently acquired lens, still testing)
- SMC Pentax-FA 645 150–300mm f/5.6 ED [IF] (~90mm-180mm) (group shots, wider perspective/environmental wild horse portraits)
- SMC Pentax-FA 645 45–85mm f/4.5 (~28mm-52mm) (landscapes/environment)
- SMC Pentax-FA 645 80–160mm f/4.5 (50mm-100mm) (wild horse landscapes and environmental images)
645 to 35mm Lens Equivalent Chart
| 645 Lens | 35mm Equivalent (0.62 crop factor) |
| 35mm | 21mm |
| 45mm | 28mm |
| 55mm | 35mm |
| 75mm | 45mm |
| 80mm | 50mm |
| 120mm | 75mm |
| 135mm | 85mm |
| 140mm | 87mm |
| 150mm | 90mm |
| 200mm | 125mm |
| 300mm | 180mm |
| 400mm | 250mm |
| 600mm | 375mm |
645N vs. 645N II
Several people emailed me asking about the differences between the 645N and 645N II, so I created this quick summary to help illustrate the main differences.
The Pentax 645N and 645NII are both advanced medium-format SLR cameras, with the 645NII introducing several enhancements over the 645N:
Mirror Lock-Up (MLU): The 645NII features a mirror lock-up function, allowing the mirror to be raised before exposure to minimize camera shake—a valuable addition for long-exposure photography. The 645N lacks this feature.
Shutter Speed Increments: The 645NII allows shutter speed adjustments in 0.5-stop increments, providing finer control over exposure settings. The 645N offers full-stop adjustments. This feature is very important for me since I am limited to ISO 200 (HP5 film) and often work in challenging low-light conditions.
Exposure Compensation and Bracketing Steps: The 645NII supports exposure compensation and auto-bracketing in 0.5-stop increments, offering more precise exposure control than the 645N’s full-stop increments.
Custom Functions: The 645NII introduces 10 customizable functions, allowing photographers to tailor camera settings to their preferences. These functions include imprinting characters on negatives, setting shutter speed steps, and adjusting the metering timer.
Data Imprinting: Both models can imprint exposure data on the film edge; however, the 645NII offers additional information and a smaller character size for the imprinted data. I love knowing what focal length and aperture I used for each exposure.
Self-Timer Delay: The 645NII offers a customizable self-timer delay, allowing users to set it to 12 or 2 seconds, whereas the 645N has a fixed delay time.
Metering Timer Duration: The 645NII allows users to set the metering timer duration to 10, 20, or 30 seconds, offering flexibility in exposure measurement.
Finish and Aesthetics: The 645NII features a new exterior finish, providing a different tactile feel and appearance compared to the 645N. I find the 645N II feels better in my hands in the field.
While both cameras share core functionalities, the 645NII offers additional features and refinements that enhance user control and customization. These may or may not be important for your scenario, but now you know the main differences and can make an informed decision.
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Pentax Custom Functions
Here is a step-by-step guide for all 10 Pentax Custom Functions (Pentax Functions No.0 to No.9) based on the Pentax 645NII manual.
How to Set Pentax Custom Functions on the Pentax 645NII
- Turn on the camera.
- Set the exposure compensation dial to “PF” (Pentax Functions Mode).
- Use the Up/Down buttons to navigate through the Pentax Functions No.0 to No.9 on the LCD.
- Press the AE-L (AE Lock) button to toggle between available settings.
- Once the desired setting is selected, turn the exposure compensation dial away from PF to save the setting.
- The camera will now use the updated function settings.
Pentax 645NII Custom Functions List
[PF 0] – Imprinting a Character on the Negative
- Allows the imprinting of a capital letter (A-G) on the film negative.
- Useful for photographers using multiple cameras for film identification.
[PF 1] – Setting the Shutter Speed Step
- Determines the step size of the shutter speed dial when adjusting exposure.
- 1/2 EV step (Default)
- 1.0 EV step (for full-stop increments)
[PF 2] – Adjusting the Metering Timer Duration
- Sets how long the metering system remains active after pressing the shutter button.
- 10 seconds (Default)
- 20 seconds
- 30 seconds
[PF 3] – Auto-Bracketing Sequence Order
- Sets the order in which bracketing exposures are taken:
- Default: Proper → Under → Over
- Alternative: Under → Proper → Over
- Alternative: Over → Proper → Under
[PF 4] – Self-Timer Delay Time
- Adjusts the self-timer delay before exposure:
- 12 seconds (Default)
- 2 seconds with mirror lock-up (I find this more useful)
[PF 5] – Exposure Compensation Step Size
- Determines how exposure compensation is adjusted.
- 1/3 EV step (Default)
- 1/2 EV step
[PF 6] – Program Line Shift
- Controls whether the Program AE Mode allows manual shifting of the aperture and shutter speed combination.
- Disabled (Default)
- Enabled (Allows shifting in 0.5 EV steps)
[PF 7] – Frame Counter Display Mode
- Selects whether the frame counter counts up or down.
- Count-Up (Default)
- Count-Down (I think this is more useful)
[PF 8] – Viewfinder Frame Counter Display
- Enables or disables the number of films taken and frame counter display in the viewfinder.
- Disabled (Default)
- Enabled (I like this enabled)
[PF 9] – Changing the Number of Frames per Roll
- Adjusts the number of exposures per roll of 120 or 220 film.
- 15 frames (120) / 32 frames (220) (Default)
- 16 frames (120) / 33 frames (220) (I like this set to 16 frames per roll)
📌 Important Note: The number of frames must be set before the first frame is taken. Once the first frame is exposed, this setting cannot be changed until the film is removed.
How to Reset All Pentax Functions to Default
- Set the exposure compensation dial to PF.
- Hold down both the Up and Down buttons for more than 2 seconds.
- “N” will appear on the LCD panel, indicating all Pentax Functions have been reset.
This step restores all settings to factory defaults.
Ready to take your film photography to the next level? Mastering the art and science of properly scanning and editing your negatives is essential for achieving the best possible results. Whether you’re shooting 35mm, medium format, or large format, a well-executed hybrid workflow can unlock the full tonal range and character of your film. Join me as we dive into proven techniques that preserve the analog soul while delivering beautifully polished images ready for print or screen. For in-depth tutorials, workflow breakdowns, and direct access to my personal guidance, become a member of the Darkroom Diary Premium Membership and start transforming your scans into gallery-worthy prints.
