Pentax 50mm F/2.8 SMC Macro D FA K Mount Autofocus Lens {49}

Pentax 50mm f/2.8 macro with 1:1 magnification for K-mount shooters

The smc P-D FA 50mm f/2.8 Macro covers the full 35mm format image circle and reaches true 1:1 life-size magnification, making it a capable macro option for any Pentax K-mount body. The optical formula has been tuned specifically for digital sensors, with coating improvements and repositioned elements that reduce flare and ghosting, problems that punish digital sensors far more than film. Autofocus is included, which matters when you're working at close distances and need to make fast decisions about where to lock focus.

The P-D FA designation signals that this lens is optimized for both digital SLR and film bodies, so it works across whatever Pentax system you're running. The 49mm filter thread keeps accessories costs modest. Pentax's Super Multi-Coating keeps contrast and color accuracy strong even when shooting toward a light source. For a 1:1 macro lens with autofocus, the compact footprint is a real practical advantage over conventional macro designs that tend to be heavy and front-heavy.

Who It's For

Close-up and macro photographers who want 1:1 magnification without carrying a heavy, oversized lens will find the compact build genuinely useful in the field or on a copy stand. Product photographers working with small objects benefit from the autofocus, which speeds up focus confirmation when shooting tethered. Film Pentax shooters who've moved to a digital body get full 35mm image circle coverage with no crop penalty. Studio and nature photographers who already own 49mm filter accessories can use their existing stack directly on this lens.

Key Features

• 50mm focal length with f/2.8 maximum aperture
• 1:1 life-size macro magnification without extension tubes
• Pentax K-mount with full 35mm image circle coverage
• Autofocus with compact, lightweight optical design
• Super Multi-Coating reduces flare and ghosting on digital sensors
• 49mm filter thread
• Optimized for both digital SLR and film bodies

FAQ

Does this lens work on both film and digital Pentax bodies?

Yes. The P-D FA designation means it's optimized for both digital SLRs and film cameras on the K-mount. You get the same optical formula across your entire Pentax system.

What's the minimum focusing distance?

The lens achieves 1:1 magnification, meaning it focuses close enough to reproduce subjects at life-size on the sensor. Exact working distance varies depending on how you measure it, but 1:1 macro magnification is the standard specification.

Is autofocus reliable at 1:1 magnification?

Autofocus is included and functional at macro distances, which is useful for fast focus decisions when working close. At true 1:1, depth of field is razor-thin regardless of lens, so precise manual focus adjustment is often preferred for critical work.

How does this compare to manual-focus macro lenses?

The autofocus mechanism adds convenience without the bulk or weight penalty typical of older macro designs. Pentax kept the overall footprint compact by designing the AF system efficiently from the start.

What kind of coating does it have?

Super Multi-Coating (SMC) with repositioned elements to minimize flare and ghosting, problems that hit digital sensors harder than film. This optimization is part of the P-D FA series design.

Will I need an extension tube or teleconverter with this lens?

At 1:1 magnification, you have true macro capability built in. Extension tubes and teleconverters are optional depending on whether you want magnification beyond 1:1 or a different working distance.

What filter size do I need?

49mm. The modest thread size keeps accessory costs reasonable compared to larger macro lenses.