HD vs. SMC Pentax-DA 18-50mm F4-5.6
Specifications
Like all manufacturers, Pentax likes to use many acronyms and make lens names as long as possible. The following table summarizes many of the terms used in the name and description of the lenses.
| SMC | "Super Multi-Coating", the name of the famous Pentax coatings used for many decades (with improvements added over time). It was replaced almost completely in 2012 by the new "HD" coating. |
| HD | "High Definition" is the newest generation of multi-coatings by Pentax. It offers better flare resistance. |
| SP | "SP" is not part of the lens's name, but still an important part of its characteristics. Super protect is a type of coating used by Pentax that helps repel dust and grease, making the lens easier to clean. It is often present on WR lenses. |
| DA / DA L | "D" refers to a lens designed for digital cameras, carrying information used for specific program lines, in-camera lens correction and so forth. "DA" signifies that the lens can be used with APS-C cameras, not full frame. A lens labeled "DA L" lacks quick-shift and has a lighter, plastic mount. |
| F | "F" is the maximum aperture of the lens. The maximum aperture shrinks as you zoom, hence the presence of two numbers. |
| DC | "DC" means that the lens uses a Direct Current autofocus drive. the AF motor is inside the lens, the camera body simply provides power. DC is near-silent and potentially faster. |
| WR | "WR" means the the lens is weather resistant. It cannot be submerged but will resist splashes, rain, snow, dust and other adverse conditions. |
| RE | "RE" means the lens can be retracted when not in use, reducing its length. The 18-50mm debuts this feature. |
There are currently 7 versions of the various Pentax digital kit lenses. Below, we highlight the main differences between each:
| Name | 18-55mm | 18-50mm | |||||
| SMC DA | SMC DA II | SMC DA L | SMC DA WR | SMC DA L WR | SMC DA L RE | HD DA RE | |
| Year Launched | 2006 | 2008 | 2009 | 2009 | 2013 | 2015 | 2015 |
| Focal length | 18-55mm | 18-50mm | |||||
| Aperture | F3.5-5.6 | F4-5.6 | |||||
| Aperture Blades | 6 | 7 (rounded) | |||||
| Mount | Metal | Metal | Plastic | Metal | Plastic | Plastic | Plastic |
| Quick-shift | Yes | Yes | No | Yes | No | Yes | Yes |
| Manual Focus | Mechanical | By Wire* | |||||
| Weather resistance | No | No | No | Yes | Yes | Yes | Yes |
| Autofocus | Screw | DC | |||||
| Supplied Hood | Petal | Petal | N/A | Petal | N/A | N/A | Window |
| Colors | Black | Black | Black, white, custom | Black | Black, white, custom | Black or white | Black |
*Renders the lens incompatible with very old bodies such as the *ist D and K110D, since focusing (even manually) is not possible due to the lack of electrical contracts.
Here are the complete specifications of the two lenses under test.
| Lens Name |
HD Pentax-DA 18-50mm F4-5.6 DC WR RE |
SMC Pentax-DA 18-55mm F3.5-5.6 AL WR |
| Optical Formula | 11 elements, 8 groups (1 aspherical element, 1 ED element) | 11 elements, 8 groups |
| Coatings | HD, SP | SMC, SP |
| Image Circle | APS-C | APS-C |
| Auto-Exposure Support | Yes | Yes |
| Construction | Plastic (including mount) | Plastic (metal mount) |
| Field of View (diagonal) | 76-31.5° | 76-29° |
| Aperture Range | F4-5.6 | F3.5-5.6 |
| Aperture Blades | 7 (rounded) | 6 |
| Aperture Ring | No | No |
| Max. Magnification | 0.23x | 0.34x |
| Focus Type | AF, DC, quick-shift (by wire) | AF, screw-drive, quick-shift |
| Manual focus | Motorized (by wire) | Mechanical |
| Minimum Focusing Distance | 30cm | 25cm |
| Internal Focus | No | No |
| Filter Thread Diameter | 58mm | 52mm |
| Cap | Yes, push-on (clip-on for DA L) | Yes, clip-on |
| Hood | Yes, window (PH-RBJ58) | Yes, petal-shaped (PH-RBC) |
| Case | No | No |
| Diameter x Length | 71 x 41 mm (2.8 x 1.6 in.) collapsed | 68 x 67.5 mm (2.7 x 2.7 in.) |
| Weight | 158 g (5.6 oz.) | 230 g (8.1 oz) |
| Pentax Mount Designation | KAF3 | KAF |
| Weather Sealing | Yes | Yes |
| Price (US MSRP) | $299 | $199 |
| Launch Date | February 2015 | 2009 |
On paper, the two lenses are quite similar, just like we would expect. The shorter focal length of the HD lens translates into a field of view that's smaller by 2.5°. The smaller size represents a 30% weight difference when discounting the hoods, no small feat.
