Pentax HD Pentax D FA* 50mm F1.4 SDM AW lens

The Pentax HD Pentax D FA* 50mm F1.4 SDM AW is a K-mount autofocus prime with a bright F1.4 maximum aperture. It is aimed at portraiture and low-light photography, while its listed mount compatibility and electronic diaphragm requirements make camera-body compatibility worth checking before purchase.

At a glance

The F1.4 maximum aperture is presented for portrait backgrounds and handheld indoor or low-light shooting.
The listing describes an autofocus motor and a rounded nine-blade diaphragm, with natural bokeh claimed up to F2.8.
The AW design is described as dustproof and weather-resistant, with eight seals. Pentax says this is intended to work alongside a weather-resistant camera body.
Pentax describes Aero Bright Coating II and HD Coating as reducing reflections, flare and ghosting.
The lens uses Pentax K mount. The listed electromagnetic diaphragm compatible camera models include some bodies that require a firmware update.

Price

£1,039.99Save 20%

Reference price: ~~£1,299.00~~

Price checked: 14 Nov 2026

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Pros and cons

Pros

The F1.4 aperture supports shallow-depth-of-field portrait work and gives the listing's stated low-light use case.
The manufacturer describes eight-seal dustproof and weather-resistant construction for use in demanding outdoor conditions.
The listing claims a rounded nine-blade diaphragm and coating treatments intended to support pleasing out-of-focus areas and reduce flare.

Technical specifications

21 specifications

Identity
Brand	Pentax
Model	HD Pentax D FA* 50mm 1.4 SDM AW

Camera optics
Focal length	50 mm
Lens type	Standard Prime
Focus type	Auto Focus
Mount compatibility	Pentax KAF
Lens design	Fixed
Zoom ratio listed	1:1
Maximum aperture listed	16 Millimetres
Minimum aperture listed	1.4 Millimetres
Diaphragm blades	9
Coating description	Super Integrated Coating
Angle of view listed	47 arcmin

Compatibility and use
Compatible camera models	Pentax K-mount cameras
Compatible devices	Pentax DSLR
Exposure control type	Manual
Viewfinder type	Optical viewfinder

Dimensions and installation
Filter size	72 Millimeters
Weight listed	2.1 Pounds

Materials and protection
Water resistance listed	Not Water Resistant
Colour	black

What to know before buying

Listing details to confirm

Listing details conflict or appear inconsistent: the maximum and minimum aperture fields give values with Millimetres units that do not match the F1.4 aperture claim, the listed zoom ratio is 1:1 despite the fixed 50 mm prime description, and the angle-of-view value is given as 47 arcmin. The listing also calls the lens not water resistant while describing its AW seals as weather-resistant. Confirm the intended technical specifications and camera compatibility before buying. Accessories such as hood, caps and case are claimed in one kit description but are not corroborated by the explicit contents list, so confirm the selected listing's package.

What’s in the box

HD Pentax D FA* 50mm F1.4 SDM AW lensIncluded
Front lens capCheck selected pack
Lens mount capCheck selected pack
Lens hood PH-RBB72Check selected pack
Lens case S100-140Check selected pack

Check which accessories are included in your selected pack before buying.

Who is it for?

A good fit for

Pentax K-mount DSLR owners seeking an autofocus 50 mm prime for portraits, indoor scenes or low-light shooting.
Photographers who want a weather-resistant lens design and already use, or plan to use, a compatible weather-resistant Pentax body.
Buyers who prioritise a wide aperture and are comfortable checking camera-body and firmware compatibility.

Less suited to

Users of non-Pentax K-mount cameras, unless they have confirmed a suitable compatible setup.
Buyers who need a zoom lens or want unambiguous specifications without checking the listing's inconsistencies.
Anyone relying on confirmed inclusion of a hood, caps or case without checking the selected package.

Pentax HD Pentax D FA* 50mm F1.4 SDM AW lens · photo 2 — Additional product photo 2

Customer reviews on Amazon

4.6 / 5 · 73 ratings

5 stars85%85%
4 stars4%4%
3 stars4%4%
2 stars4%4%
1 star3%3%

Customer feedback reports praise for image quality, sharpness, autofocus, reliability and build quality, including at F1.4. The overall rating distribution is mostly five-star but includes lower ratings, so experiences are not uniform. These reported impressions may matter to portrait and low-light users, but they do not resolve the listing's inconsistent technical fields or confirm camera compatibility.

Positive themes

Customer feedback praises image quality and sharpness, including wide-open use.
Feedback highlights autofocus, reliability and build quality.

Frequently asked questions

Which cameras is this lens listed as compatible with?

The listing names Pentax K-mount cameras and Pentax K-mount DSLRs. It also specifies KAF4 electromagnetic diaphragm compatibility with the K-1 Mark II, K-1, K-3 II, KP, K-70, K-3, K-S2, K-S1 and K-50. For the K-1, K-3 II, K-3, K-S2, K-S1 and K-50, it says the camera firmware must be updated to the latest version.

Is this a zoom lens?

It is described as a fixed-focus-length Standard Prime with a 50 mm focal length. The listing also gives a 1:1 zoom ratio, which conflicts with that description and should be clarified.

Is it suitable for outdoor use?

The manufacturer describes dustproof, weather-resistant construction with eight seals, but says it should be paired with a weather-resistant Pentax DSLR. A separate listing field says “Not Water Resistant”, so clarify the protection claim for your intended conditions.

What comes in the box?

The listing's accessory claim names front and mount caps, hood PH-RBB72 and case S100-140, but the explicit contents list does not corroborate those items. Check the selected package before purchase.