Ready to go deeper with your photography? – Join the Darkroom Diary Premium Membership—a creative refuge for film photographers working with 35mm, medium format, or large format. Whether you’re scanning and sharing or crafting fine art prints, you’ll find expert guidance, meaningful conversation, and a supportive community focused on vision, process, and emotional impact. Join today and start creating work that truly matters.
Table of Contents
The Original Pentax 645 — A Workhorse Medium Format SLR Built for the Long Haul
The original Pentax 645 manual focus camera is, in my opinion, one of the best cameras ever made.
In an era when convenience often replaces craft, the original Pentax 645 reminds us what it means to slow down and work with intention. Released in 1984 by Asahi Optical Co., this medium-format SLR camera was Pentax’s answer to photographers demanding a rugged, reliable system that delivered 6×4.5cm negatives—without the bulk or fuss of larger medium-format gear.
As someone who creates by hand using historic photographic processes, I’m drawn to tools that get out of the way and let me focus on my subject. The original Pentax 645 is one of those tools. It’s not flashy, it’s not autofocus, and it certainly doesn’t care about megapixels. What it offers instead is a robust and efficient shooting experience with just enough automation to keep your focus where it belongs—on seeing.
A 645 film (56 x 41.5mm) has 2.6 times the area of a full-frame 35mm film (36 x 24mm), and when comparing lenses to 35mm, apply a 0.62 crop factor.
I am using the following lenses for my wild horse, nature, and landscape 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)
Build and Handling
This camera is built like a tank, weighing in at about 1,430 grams (3.15 lbs) without batteries. But don’t let that scare you. With a properly fitted strap or grip, it balances beautifully, especially with the standard SMC Pentax-A 75mm f/2.8 lens mounted. The body is primarily metal, wrapped in a textured polycarbonate exterior that still feels solid decades later.
It’s not modular like the Mamiya RB/RZ systems—no interchangeable viewfinders or film backs—but that’s actually part of the charm. What you lose in modularity, you gain in speed, simplicity, and reliability. The motorized film advance automatically sets the next frame, and loading film is remarkably easy thanks to the removable film insert system.
Viewfinder and Focusing
The fixed pentaprism offers a bright, clear view with approximately 92% coverage and 0.78x magnification. Focusing is manual only—there’s no autofocus in this body—but the standard focusing screen and diopter adjustment make precision focusing straightforward. For those of us used to large format ground glass, this is quick and intuitive.
And here’s the good news: Pentax 645 FA lenses work perfectly on this body—in full manual focus mode. You retain all metering and exposure functions, just not the autofocus.
Exposure and Metering
The Pentax 645 offers three exposure modes: Manual, Aperture Priority (Av), and Program (P). It uses a TTL center-weighted metering system that’s consistent and predictable. Set your lens to the “A” position, and the camera takes care of the rest in Program or Av mode. Shutter speeds range from 15 seconds to 1/1000s, plus Bulb, with 1/60s flash sync.
The metering readout in the viewfinder shows your selected shutter speed and metered suggestions. It’s powered by six AA batteries, making this one of the more accessible and globally serviceable medium-format systems.
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.
Lens System: The Heart of the 645
One of the strongest features of the original Pentax 645 system is its exceptional lens lineup—particularly the Pentax-A 645 series, which was purpose-built for this camera. These manual focus lenses are fully integrated with the body’s metering and exposure modes, including Program (P), Aperture Priority (Av), and Manual (M).
Every lens in the A-series features:
- A robust bayonet mount
- Smooth manual focusing
- Multicoated optics for excellent contrast and color
- An “A” setting on the aperture ring to enable autoexposure modes
Here’s the complete lineup of Pentax-A 645 manual focus lenses available for the original 645:
Wide-Angle Lenses
- 35mm f/3.5 A – The widest native lens, excellent for sweeping landscapes.
- 45mm f/2.8 A – A classic wide-angle with natural rendering.
- 55mm f/2.8 A – Ideal general-purpose wide with minimal distortion.
Standard Lenses
- 75mm f/2.8 A – The standard lens; compact, sharp, and affordable.
- 80mm f/2.8 A – Slightly tighter field of view; excellent for portrait work.
Telephoto Lenses
- 120mm f/4 A Macro – A brilliant macro lens with 1:1 magnification; very sharp.
- 150mm f/3.5 A – Short telephoto for portraits with pleasing background separation.
- 200mm f/4 A – Great for landscape compression or candid portraiture.
- 300mm f/4 A ED(IF) – Long reach with excellent optical correction and internal focusing.
Zoom Lenses
- 45–85mm f/4.5 A – Versatile wide-to-standard zoom; solid performer.
- 80–160mm f/4.5 A – Great walkaround zoom; often underrated.
- 150–300mm f/5.6 A – A big lens with reach—suited to wildlife or compressed scenes.
Specialty Lenses
- 75mm f/2.8 Shift A – Offers ±20mm shift for correcting converging lines in architecture.
Using FA Autofocus Lenses on the Original Pentax 645
While the original Pentax 645 body is manual focus only, it accepts all later Pentax-FA 645 autofocus lenses thanks to the identical mount. These lenses:
- Function just like A-series lenses on this body
- Offer full manual focus control
- Retain electronic aperture coupling, allowing use of Program, Av, and Manual modes
You can’t autofocus with these lenses on the original body, but everything else works as it should.
This backward compatibility lets you invest in FA glass now—even if you upgrade to a 645N, 645NII, or 645D/Z digital body later.
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 |
Lens Recommendations
If you’re starting out, the 75mm f/2.8 A is a superb all-around choice. For portraits or flower studies, the 120mm Macro or 150mm f/3.5 render beautifully. And if you prefer wide-angle perspectives, the 35mm f/3.5 A is among the best wide-angle lenses ever made for medium format.
If you enjoy slowing down with film, darkroom printing, and meaningful photography, consider subscribing to my YouTube channel. I share new videos each week focused on simple tools, timeless techniques, and the quiet joy of analog.
In Use: A Photographer’s Perspective
In the field, this camera feels like a 35mm SLR on steroids. It’s fast enough to handle dynamic situations but deliberate enough to keep you from overshooting. That’s a balance I respect.
For my own work—particularly when I need a dependable system camera to create small jewel-like contact prints or big enlargements—the 645 delivers. The 6×4.5cm negative is noticeably sharper and smoother than 35mm, and yet more economical and faster to work with than 6×7 or 6×9. I feel like it is the perfect balance between size, weight, value, and image quality.
For me, handling 35mm film is irritating, and the worse my eyes get over time, the more troublesome it becomes. Plus, I can’t relate to taking 36 exposures on a single roll of 35mm film. The image quality between 35mm and 6×4.5 medium format is no comparison.
It’s also my go-to for making work prints or studies before committing to large format. For example, I will scout with the 645 and if I really like the image, I will return with my 8×10 and make a handmade calotype paper negative. Of course, I could scout with my phone camera or something digital, but I don’t feel the same about the images and how I can potentially visualize them.
Sometimes, less is more—and the Pentax 645 proves that with every frame.
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.
What I Love
The original Pentax 645 is an excellent example of when we got it right with making cameras. It has all the fancy features like metering and automatic film advance that you could ever want, but, more importantly, it doesn’t have things we don’t need. The camera’s build quality is another excellent example of an era that no longer exists. My camera was purchased new in 1984, and it still works as well as the day I got it, over 40 years ago. No digital camera made today will likely be able to make that claim.
You can find these cameras and lenses on eBay for very reasonable prices, starting in the $250 to $300 range, and they will be in excellent condition. Also, the available lenses for this camera are second to none in my opinion. You can buy this camera in 2025 (41 years after its release) and use it for the rest of your life without ever needing an upgrade or change. Heck, at these prices, buy two and have a backup in case something happens to your primary camera.
Most importantly, I feel connected to my subjects and scenes when using this camera. I control everything, and I know that when I create a great image with this camera, it’s because of me —the photographer —who made the right choices and executed everything perfectly. I use this camera for everything from my wild horse photos to landscapes, macros, and still life.
- Efficient workflow: Fast film loading, motor advance, and simple operation.
- Incredible lenses: Sharp, characterful optics with smooth rendering.
- Durability: Decades later, still fully functional and field-ready.
- Backward compatibility: Works seamlessly with both A-series and FA lenses.
What to Keep in Mind
- No autofocus: You’ll focus manually, but that’s part of the joy.
- Fixed viewfinder: No waist-level options here.
- 1/60s flash sync: Somewhat limiting for strobe-heavy work.
- Heavier than it looks: It’s compact but dense—use a solid strap.
Final Thoughts
The original Pentax 645 is a no-nonsense workhorse that rewards photographers who value intention over automation. It may not have the cult following of a Hasselblad or the modular flash of a Mamiya, but in the right hands, it quietly outperforms expectations. For anyone shooting medium format film—whether for traditional silver gelatin, alt processes, or contact printing—the 645 deserves serious consideration.
It’s not just a camera. It’s a reminder that slowing down isn’t a limitation—it’s a way of seeing more clearly.
If you want to explore the full story of these innovations and how they shaped the dawn of photography, join the Darkroom Diary Premium Membership. Access this complete article and an entire library of exclusive content, where history, science, and artistry converge to celebrate the timeless craft of analog photography.
My Personal Camera
