Pentax HD PENTAX-D FA 28050 21mm
Combining a 21mm ultra-wide perspective with a bright f/2.4 aperture and 4 ED elements, this lens delivers sharp, high-resolution images with uniform rendition across the full-frame field. Its weather-resistant construction and close 7.1" minimum focusing distance add practical versatility to the precision-machined Limited-series build. This optic is best for landscape and architectural photographers using Pentax K-mount DSLRs who need durable, all-weather performance.
요약
The 30-Second Version
A stunningly built, razor-sharp wide prime that's pure Pentax soul. It's expensive and a bit slow, but nothing else feels this good in your hands.
Pros & Cons
장점
- All-metal, weather-sealed build that feels like a family heirloom 87th
- Exceptional close-focus performance for a wide-angle lens 78th
- Renders with a gorgeous, natural character and great sharpness 77th
- Compact and lightweight at just 416g, perfect for hiking
단점
- f/2.4 is slow for a prime, limiting low-light and astro work
- Autofocus is audible and not competitive with modern ring-type motors
- Bokeh is a weak spot, with busy rendering at wider apertures
- The price tag is a gut punch compared to similar mirrorless options
사용자 의견
The Word on the Street
시간에 따라 사용자 평판이 어떻게 변했는가
독점고객이 실제로 리뷰를 작성한 시점을 기준으로 합니다. 초기의 호평이 유지되었는지 확인할 수 있습니다.
날짜가 있는 고객 리뷰 9건을 기준으로 달력 분기별로 묶었습니다. 기간별 분석은 영어로 제공됩니다.
근거 자료
Performance
What surprised us most is how good this lens is at close range. Its macro score sits in the 85th percentile of our database, which is a standout result for a wide-angle prime. The 7.1-inch minimum focus distance lets you get right up on a subject, and the f/2.4 aperture is just fast enough to throw a busy background out of focus for some dramatic wide-angle detail shots. Sharpness is excellent across the frame thanks to those four ED elements, though the autofocus is just middle of the pack, not the silent, lightning-fast stuff you'd get on a modern mirrorless system.
Specifications
Full Specifications
Optics
| Type | Wide-angle |
| Focal Length Min | 21 |
| Focal Length Max | 21 |
| Elements | 11 |
| Groups | 8 |
| Aspherical Elements | 1 |
| ED Elements | 4 |
| Coating | High-Grade Multi-Layer HD Coating |
Aperture
| Max Aperture | f/22 |
| Min Aperture | f/2.4 |
| Constant | Yes |
| Diaphragm Blades | 8 |
Build
| Mount | Pentax K |
| Format | full-frame |
| Weather Sealed | Yes |
| Weight | 0.4 kg / 0.9 lbs |
| Filter Thread | 67 |
AF & Stabilization
| AF Type | Autofocus |
| Stabilization | No |
Focus
| Min Focus Distance | 180 |
| Max Magnification | 1:3.85 |
vs Competition
This is a prime lens, so comparing it to the superzooms in its competitor list like the Sigma 16-300mm or Tamron 18-300mm is a bit silly. Those are Swiss Army knives, this is a chef's knife. The real competition is something like a used Canon RF 28-70mm f/2.8 on a modern mirrorless body. That Canon zoom is more versatile and faster, but it can't touch the Pentax's compact size, weather sealing, or the sheer joy of its all-metal manual focus feel. If you're already in the Pentax ecosystem, this is the best wide prime you can get. If you're not, the cost of entry to use this one lens is astronomical.
| Spec | Pentax HD PENTAX-D FA 28050 21mm | Sigma Contemporary 18-50mm f/2.8 DC DN | Tamron Di III 17-70mm f/2.8 Di III-A VC RXD | Nikon NIKKOR Z 17-28mm f/2.8 | Panasonic Leica DG Vario-Elmarit H-ES12035 | Sony E 18-135mm f/3.5-5.6 OSS |
|---|---|---|---|---|---|---|
| Focal Length | 21mm | 18-50mm | 17-70mm | 17-28mm | 12-35mm | 18-135mm |
| Max Aperture | f/22 | f/2.8 | f/2.8 | f/2.8 | f/2.8 | f/3.5 |
| Mount | Pentax K | Sony E | Sony E | Nikon Z | Micro Four Thirds | Sony E |
| Stabilization | false | false | true | false | true | true |
| Weather Sealed | true | true | true | true | true | false |
| Weight (g) | 416 | 290 | 544 | 450 | 306 | 326 |
| AF Type | Autofocus | stepping motor | RXD | Stepping Motor | Autofocus | Linear motor |
| Lens Type | wide-angle | zoom | zoom | zoom | zoom | zoom |
| Compare | Compare | Compare | Compare | Compare |
| 제품 | AF | Bokeh | Build | Macro | Optical | Aperture | User Sentiment | Versatility | 사용자 평판 | Stabilization |
|---|---|---|---|---|---|---|---|---|---|---|
| Pentax HD PENTAX-D FA 28050 21mm | 53.7 | 17.9 | 77.6 | 86.5 | 76.5 | 19.8 | 63.7 | 33.7 | 60.8 | 36.7 |
| Sigma Contemporary 18-50mm f/2.8 DC DN Compare | 86.8 | 81.1 | 86.4 | 91.4 | 82.4 | 83.3 | 80.9 | 78.6 | 90.2 | 36.7 |
| Tamron Di III 17-70mm f/2.8 Di III-A VC RXD Compare | 53.7 | 86.4 | 69 | 85.5 | 91.2 | 83.3 | 63.7 | 89.6 | 86 | 82.4 |
| Nikon NIKKOR Z 17-28mm f/2.8 Compare | 86.8 | 86.4 | 75.6 | 85.5 | 88.3 | 83.3 | 91.2 | 68.1 | 70.8 | 36.7 |
| Panasonic Leica DG Vario-Elmarit H-ES12035 Compare | 53.7 | 81.1 | 85.7 | 50.7 | 86.6 | 83.3 | 63.7 | 80.6 | 86 | 96.9 |
| Sony E 18-135mm f/3.5-5.6 OSS Compare | 98 | 74.6 | 72.9 | 40.3 | 78.7 | 76.6 | 44.7 | 95.8 | 90.2 | 82.4 |
가격
Value & Pricing
Let's be real, the pricing on this lens is all over the map, with a spread of over $300,000 across vendors. Ignore the obvious data errors and you're looking at a street price around $1,300. For a K-mount shooter, the value is there if you demand the best optical quality and that tank-like Limited build. For anyone else, it's a tough sell. You can get a stellar wide zoom on other systems for less, but you won't get this specific, premium experience.
Amazon.es 가격 1개 최저 €1,223
Price History
더 보기
Overview
The Pentax HD D FA 21mm f/2.4 Limited is a lens that makes zero apologies for what it is. It's a beautifully built, all-metal prime designed for Pentaxians who want the best wide-angle glass you can bolt onto a K-1. The one thing to know? This lens is an event. It's sharp, it's weather-sealed, and it renders images with a character that modern mirrorless lenses often sterilize right out of the picture. But you're paying a serious premium for the Limited badge and that silver finish.
Common Questions
Q: Is this lens good for astrophotography?
It's okay, but not ideal. The f/2.4 aperture is a bit slow for gathering light from stars, so you'll need to crank your ISO higher than you would with an f/1.4 or f/1.8 lens. The sharpness is there, but you can find better astro-specific glass for less money.
Q: How does the autofocus perform on a K-1?
It's accurate, but it's not fast or quiet. You'll hear a screw-drive whirring sound. For landscapes and architecture, it's perfectly fine. For anything moving quickly or for video work where you need silence, it's going to frustrate you.
Q: Does the weather sealing actually hold up?
Absolutely. This is a Pentax Limited lens, so the weather sealing is legit. Paired with a weather-sealed body like the K-1, you can shoot in rain or dusty conditions without a second thought. Just make sure you have a filter on the front to complete the seal.
Who Should Skip This
If you're looking for a versatile, do-it-all zoom or a fast lens for blurry backgrounds, this isn't it. Go get the Pentax 24-70mm f/2.8 instead. And if you're not already deeply invested in Pentax K-mount cameras, the cost of this lens plus a body makes no sense when a Nikon Z or Sony E-mount system will give you more modern performance for the same total price.
Verdict
The Pentax 21mm f/2.4 Limited is a niche masterpiece. It's for the photographer who values the experience of shooting as much as the final image. The build quality is top-tier, the close-focus ability is a standout, and the image quality is beautiful. Just know that you're buying into a feeling, not a spec sheet. The slow aperture and dated autofocus mean it's not the best tool for fast-paced work or video, but for a deliberate, landscape-focused shooter on a Pentax body, it's an easy recommendation.