Pentax Lens Guide for Beginners in 2022

Kit lenses, bundles, and other great first options

By wadge22 in Gear Guides on Mar 8, 2022

Buying your first lens to go with your new camera can be a daunting task. There are many options available on the market, particularly for Pentax APS-C shooters such as anyone buying a Pentax K-70. The fact that Pentax has a one of most complete lineups of APS-C lenses of any manufacturer with its DA series of primes and zooms, as well as the fact that these cameras can use any other K-mount lens from the current lineup or going all the way back to 1975, means there is plenty of overlap between the numerous choices.

This guide will attempt to make it simple for someone new to photography to pick the right lens or lens combo to go with their camera, and will cover the top choices that are available new from Pentax today. Most lenses in this guide are available as a kit with the K-70 from major camera retailers, such as B&H Photo or Adorama.

A Great Choice for Beginners

The Pentax K-70 is the entry level DSLR from Pentax, although it's capabilities and build quality would land it in the mid range of the lineup for many manufacturers: it features a 24.2 megapixel APS-C sensor with impressive image quality, in body shake reduction, dual control wheels, an articulating screen, and easy to use scene modes as well as advanced modes such as Pixel Shift super resolution. All of this comes at a very reasonable price (at time of writing in March 2022) of only US$546 for the camera body alone. However, for new users who will also be shopping for their first lens, a better deal can be found by purchasing the camera with a bundled lens. In this guide, we will attempt to give the new camera purchaser all that they need to choose which lens or lenses will suit them best with their new K-70, or any other APS-C Pentax camera.

The Basics

For starters, it will be helpful to explain some of the most important terms, and to give a brief overview of the typical uses for common focal lengths of lenses.

Probably the most important aspect of a lens to determine what it will be useful for is it's focal length. The focal length of a lens is a physical characteristic of the design of a lens that determines it's angle of view (or field of view), which is how much of a scene in front of the camera will be in the photograph when you take the picture. Some lenses are designed to take in as much of the scenery in front of the camera as possible, others are designed to reach out and capture small or distant details from that larger view, and many lenses allow the user to select from a range of focal lengths.

Angle of view is also affected by the size of the camera's sensor, which only applies if you use the same lens on different cameras. This article will only discuss APS-C cameras, to avoid the sometimes confusing issue known as crop factor or equivalent field of view. All that you need to know for now is that focal length is the only thing that determines the field of view a lens offers on one camera, regardless of whether the lens is a DA, D FA, or any other series lens.

Focal length is measured in millimeters (mm), and will either be a single number for a prime lens or a range for a zoom lens. A prime lens, such as the HD Pentax-DA 35mm F2.8 Limited Macro, will only take in one image from one specific spot looking in the same direction. If the photographer wants to get more of the scene into the frame, they must step backwards; if they want the subject to be larger and fill the frame, they must move closer to it. A zoom lens, on the other hand, like the HD Pentax-DA 16-85mm F3.5-5.6 ED DC WR, will allow the user to zoom in or out and include more or less of what they see in front of them in their picture without moving the camera. This versatility makes zoom lenses very convenient. Primes, however, often have excellent image quality and a wider aperture compared to a similarly priced zoom.

Aperture is the other most important design feature of a lens, as it determines how much light a lens can let into the camera and onto the sensor to create the image. All modern lenses allow the photographer to open or close the aperture to let more or less light in, but some can open the aperture wider than others, so the maximum aperture available is given in the lens description.  This is expressed in F-stops (such as F1.7 or F5.6), and will be a smaller number for a lens that lets more light in. How far the lens can close the aperture, or stop down, is generally less important and is not usually noted. Prime lenses will always have one maximum aperture, while zoom lenses may have a range, such as F3.5-5.6 on the SMC Pentax-DA L 18-55mm F3.5-5.6 AL WR. This simply means the maximum aperture changes as the lens is zoomed in, in this case from F3.5 at 18mm to F5.6 at 50mm. This type of lens is a variable aperture zoom, while more advanced and expensive zooms may be fixed aperture zooms, such as the HD Pentax-DA* 16-50mm F2.8 ED PLM AW.

Lenses with a larger maximum aperture, which means a smaller F-stop number, are described as having a wide aperture or being a fast lens. an F number of 2.8 or lower is generally considered fast. Lenses with a smaller maximum aperture and a higher F number, conversely, would be called slow. This is because the shutter must be opened for a longer time to get the same image with a slow lens. Another aspect of photography that is controlled by the aperture is depth of field, or how much of the scene can be in focus at the same time. Wider apertures give a narrower depth of field, which allows the photographer to get only certain parts of what he sees in focus, with the background or foreground blurry. This affect is most familiar in portraits, when a subjects face is sharp but the scene behind them is pleasantly blurred. Finally, lenses generally become sharper when stopped down some, although this varies from lens to lens, and even at different focal lengths for zooms.

Lens Categories

Before we get into specific lens options, we should give some of the common focal lengths used for different photographs. These numbers will be for APS-C cameras (the Pentax K-70 and K-3 III, as well as all other Pentax DSLRs except for the full frame K-1 and K-1 II), and we will disregard "equivalent field of view".

Wide angle lenses are used to get all of a large scene into the frame, such as a scenic vista in a landscape photograph, or an entire room interior in a real estate photo. 16mm or 18mm are definitely considered wide angle, and anything up to about 24mm is in the wide angle category (please remember, wide angle is not the same as wide aperture). Anything wider than 16mm will let even more of the view in, and is considered ultra-wide angle, such as 14mm or 10mm lenses. These could be Fish-Eye lenses, which means they take an image with pronounced circular distortion, but not all ultra-wides will be fish-eye lenses. Wide angles are the staple of many architecture, landscape, and street photographers, and they are also great for astro shots of the whole sky with scenery in the foreground.

Next up in focal length is the normal or standard lens, which is anything around 35mm to 40mm. This field of view is generally considered to capture something close to what we perceive our own as eyes seeing, and thus is a general purpose lens. These are great for people shots including full length portraits, for street photography, for architecture, and they generally offer the most versatile field of view available. A lens with this field of view has traditionally been the first lens for anyone starting out learning photography.

Lenses longer than about 50mm are called telephotos. There are three groups of telephotos: the short telephoto which is from around 50mm to 90mm, the medium telephoto (sometimes long telephoto or simply telephoto used alone) which is anything from roughly 90mm to 200mm, and the super-telephoto which is anything longer than that. Short teles are often used for portraits, still life or product photography, and wildlife or nature shots with a lot of the scenery included. Medium telephotos are used for headshot portraits, wildlife, and sports photography. Super-teles are great for sports and wildlife, particularly small birds or animals it would be unsafe or unfeasible to approach. Medium and super telephotos are also useful for astrophotography of the moon or of deep space objects.

One last category to describe is the macro lens. This lens could be of pretty much any focal length (although rarely ultra-wide or super-telephoto), and is distinguished by its ability to get extremely close to the subject and create a large image of tiny details. Photographs of insects, watch faces or stamps, or of the amazing features of snowflakes are some examples of uses for a macro lens. Such lenses are usually also great for flowers, although most flowers do not require a genuine macro lens, and any lens with fairly close minimum focus distance will work. Minimum focus distance is a feature of the design of all lenses, and lenses can not get the subject in focus if they are closer than this number.

All Around Zooms

With the terminology and categories out of the way, it's time to dive in to some specific Pentax lenses that would make a great choice for a beginner. Most users will be best served with the versatility of a zoom lens that covers at least the wide angle and normal fields of view as their first lens.

DA L 18-55mm F3.5-5.6

The obvious first place to start is with the lens that Pentax itself designed to sell as a basic "kit lens" with it's entry level models: the SMC Pentax-DA L 18-55m F3.5-5.6 AL WR. This lens is the most basic zoom lens available bundled with the K-70, and also the most affordable: it can be had in a kit with the camera, a 64 GB SD card, a camera bag, and a UV filter, all for just $646.95 from B&H. That's a mere $100 more than the camera body alone. This lens offers the photographer everything they need to get started taking pictures the minute the camera arrives: a wide angle to normal field of view that will be great for landscape, travel, and people photography. A great feature that not all brands bring to the table in such a budget option is weather sealing, which works with the sealing in the camera body to allow use in inclement weather or dusty environments. This lens receives an overall score of 7.75 in the user reviews section at Pentax Forums. It is praised mostly for it's value and the weather sealing, with merely "reasonable" sharpness and the lack of an included hood being frequently cited as drawbacks.

DA 18-135mm F3.5-5.6

For a noticeable step up from this lens, we come next to the SMC Pentax-DA 18-135 F3.5-5.6 ED AL [IF] DC WR. This lens is also available in a bundle with the K-70 and useful accessories for $796.95. For the extra $150 over the previously mentioned lens, you really are getting a whole lot more from this lens. For starters, the focal length is significantly extended at the long end, out to the telephoto range of 135mm. This makes the 18-135 a terrific all around lens, and some users may find that even with other options at hand, they rarely find a need to take this lens off their camera. It features weather sealing like the 18-55, but goes further than that by including Quick-Shift focusing to allow the photographer to change the focus manually at any time without switching the camera out of autofocus. The autofocus is quieter thanks to the in-lens DC motor, and is generally quite speedy. This lens scored an overall 8.55 in the user reviews section, with it's very useful range and surprising image quality frequently praised. If you are able to afford to choose this lens over the 18-55, the consensus among Pentax Forums members is that it will be very much worth the upgrade.

DA 16-85mm F3.5-5.6

The third lens on the list of all-rounders is the HD Pentax-DA 16-85mm F3.5-5.6 ED DC WR. This lens is not (at time of writing) found in a bundle through B&H or Adorama, so a buyer will have to purchase it separately, which will cost them $546.95 on it's own. With the K-70 body, that comes to $1,093.90, or another $296.95 above the 18-135mm option. So what makes this lens worth the jump in price? For one thing the DA 16-85mm gives an additional 2mm of range at the wider end; don't let the small number fool you, this is a noticeable and useful increase of 7 degrees to the field of view that will make the extra difference for anyone who likes to take it all in with wide angle shots. More importantly, the image quality from this lens is at least a step above the 18-135mm, and truly is hard to surpass in a zoom without going to a pro-level lens. The edges and corners of images are much sharper than the previous two lenses, there is minimal vignetting (dark corners), and this lens needs to be stopped down less to achieve maximum image quality. Pentax Forums members generally praise this lens, giving it an average of 9.03 in the user reviews section.

Between the 16-85mm and the 18-135mm, there are frequent friendly debates on Pentax Forums over which lens is the better choice as an all-rounder for APS-C: the 16-85mm for it's image quality and slight wide angle advantage, or the 18-135mm for it's range and bargain price. There is never an obvious winner, so the clear answer seems to be that you can't go wrong with one of these two as your primary zoom.

DA 55-300mm F4.5-6.3

The last lens we will discuss as an all around zoom is not a direct competitor to the other lenses listed so far, since it's focal range is much different. This lens is the HD Pentax-DA 55-300mm F4.5-6.3 ED PLM WR RE. Ranging from short telephoto into super-telephoto territory, the lens is best suited for those who want to pick out small or distant details from a scene; it will be a top choice for beginning wildlife or sports photographers who want only one lens, or will be an excellent companion to any of the three lenses already described above to give a full range kit in two lenses. The 55-300mm can be purchased along with the K-70 for $993.90 through B&H, or in a two lens bundle with the 18-135mm and K-70 for $1,243.90. The 55-300mm PLM is weather sealed, features Quick Shift focusing, and also has PLM (Pulse Motor) autofocus drive, which delivers extremely fast, silent,  and confident autofocus performance; indeed it is frequently cited as one of the best performing autofocus lenses for Pentax. It is also retractable and features a locking mechanism to keep the lens compact and secure while carrying it around. User reviews rate this lens at 8.81, with the autofocus receiving frequent praise, while the slight drop off in image quality at the 300mm end and the somewhat limited low light performance are mentioned as drawbacks by some reviewers.

Prime Options

For some photographers, the versatility of a zoom lens is not absolutely necessary. Other considerations such as the close focusing of a macro, a wider aperture offering low light performance and ability for artistic control of out of focus areas, or simply superlative image quality across the whole frame may be desired. For those photographers, prime lenses will be the top choice. Prime lenses also bring a deliberative touch to the photographic process, requiring the photographer to plan their shot to match the focal length, or "zoom with their feet" to change the composition; many photographers find this process rewarding and engaging. Fortunately, Pentax offers many excellent prime lens options, including top performers that do not break the bank. We will focus on a couple that offer a standard angle of view on the K-70.

DA 35mm F2.4

The SMC Pentax-DA 35mm F2.4 AL is certainly one such lens. Available bundled with the K-70 for $693.00, this lens is the second cheapest kit available with the K-70. However the low price will not be reflected in the image quality with this option, because the "plastic fantastic" 35mm F2.4 truly delivers the goods that prime lenses promise from an image quality standpoint. It is very sharp, including to the edges of the frame, and it also controls distortions (noticeable bulges of straight lines) and aberrations (such as nasty purple colors in high contrast areas) very well; on par with far more expensive primes. The quite fast F2.4 aperture allows for shooting in low light without using a tripod or risking the excessive noise from raising the cameras ISO setting farther than desired, which is very helpful at dawn and dusk, or in poorly lit interiors. In the Pentax Forums user reviews this lens receives a score of 9.15, which reflects what a tremendous bargain it is. If there are drawbacks to the lens, they are the lack of weather sealing, quick shift, or advanced autofocus system, and the lightweight plastic build. Still, for the price to performance ratio, it is an excellent buy.

DA 35mm F2.8 Limited Macro

A step up in almost every way, but with the same angle of view, the next lens is the HD Pentax-DA 35mm F2.8 Limited Macro (note: this review is for the very similar SMC coated version of the same lens; Pentax updated its whole DA Limited series to the improved HD coatings in 2013). The 35mm Limited Macro is from the Limited series, which are very special lenses with high quality all metal builds and excellent image quality optimized specifically for the way photographers will use the lens. They are absolute gems, and this lens is no exception. Nevertheless, it can still be had in a kit with the K-70 for $943.90, or in a two lens K-70 bundle along with the 18-135mm for $1,193.90. For that money, you are getting a top quality lens from the Pentax lineup, one that will likely never need upgrading, no matter how far you grow in the world of photography. The 35mm Limited Macro is a true 1:1 macro lens, which means it can reproduce the subject at full size on the camera's sensor. This gives the ability to photograph the tiny world of flowers and insects in great detail. However the lens is also excellent for all around shooting at longer distances. It delivers the best image quality of any lens on this list, indeed among the best of any lens in the Pentax lineup. Going beyond just sharpness, this performance comes from such finer points of lens design as contrast and color rendition. It also sports handy features like Quick-Shift focusing, an on-lens distance scale, and a built in hood. All of this combines to earn the 35mm Limited Macro an impressive overall score of 9.61 in the user reviews. The only common complaints come from the fact that it lacks weather sealing, and that some macro photography (such as of skittish insects) benefits from longer focal lengths that allow more working distance between the camera and subject (for a lens that answers both complaints, look to the SMC Pentax-D FA 100mm F2.8 WR Macro).

Conclusion

The APS-C Pentax K-70 DSLR offers powerful capabilities and high end features for a terrific price. It is a great starting place for any photographer who is interested in the world of DSLRs, and the Pentax K-mount lens ecosystem is a big part of that proposition. Above, we have outlined some of the most obvious choices for a first lens or two that will compliment that camera, or really any new or used Pentax APS-C body. This was not an exhaustive list, and there are many other good choices in the Pentax lineup, as well as from third party manufacturers or on the second hand market. Anyone looking for their go to lens to make the most of their new camera would be well served to look at the lenses listed in this article as a starting off point.

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