Pentax DA 35mm f/2.4 AL Review

SMC Pentax-DA 35mm f2.4 AL Review
November 2011, Carl Garrard

Pentax DA 35mm f2.4 AL Lens Review
Introduction- The budget 35mm f2.4 is compact lightweight standard equivalent lens for all Pentax DSLRs (as of the time of this writing). As the name implies, it has a relatively bright max f/2.4 aperture and 50mm equivalent (in 35mm terms) field of view. This lens is for the budget conscious or those who like a good bang for the buck. Pentax denotes that this lens is good for beginners who want better picture quality from a prime lens without having to spend a lot of money to do so.


Pentax 21987 DA 35mm f/2.4 AL Lens for Pentax Digital SLR cameras

Priced at around $199.00-$229.00 USD (I landed mine for $140.00 USD), indeed this lens is one of Pentax's most affordable lenses. It lacks some of Pentax's standard features such as a distance scale, weather sealing, and quick shift focusing, but as you'll see soon, the price and performance will likely make you forget about those specifications.

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Special Features- Lets face it, it's a prime lens at a budget price. Not many features to relay here. But I will note that Pentax offers their Super SMC coating to the front element which should not be understated or taken for granted. If you clean your lens elements even half as much as I do, you'll appreciate this coating and how easily dust, oils, and water are wiped away.

Other than that, the front element does not rotate during focusing which makes for the use of circular polarizers. Pentax adorns the body of the lens with its notched grooves near the lens mount to make dismounting and mounting the 35mm f/2.4 an easier task by allowing you to keep a good grip on it.

Performance
Overall the Pentax 35mm f/2.4 is a very good to excellent performer-especially for its price. Optically there is really nothing to complain about no matter how you dissect it, no matter what the cost. As you'll see below, the images back up my opinion of this lens's performance characteristics.

Focus Speed and Accuracy
Primes like this tend to usually be quick and accurate- but with the use of the camera's focus motor I find it to be quicker than other micro motor models. Focus is fast albeit with the cost of additional noise. I found no issues with accuracy at any f-stop when mounted to the K5, K20D, or K200D.

Sharpness- From center outward this lens is sharp, starting right from its max aperture. Corners are only a tad soft at f/2.4, and really nothing to be concerned with. It reaches terminal velocity (rather, its best sharpness from corner to corner average) at about f/4, and only slightly decreases in overall resolution as you approach f/11. A very mild taper in sharpness in comparison to most lenses- rather impressive actually.

f/2.4

f/4

f/5.6

f/8

Pentax 21987 DA 35mm f/2.4 AL Lens for Pentax Digital SLR cameras


Distortion- As you can see in the test images below- Very little barrel distortion, almost imperceptible by the naked eye and not relevant on the whole. An excellent performance here. A great choice for landscape photography in this regard granted the focal length affords your compositional needs. As a standard equivalent focal length, likely it will hit more than miss in this regard.

Grid Overlay Over Test Chart (Click for larger view)

Original Image Without Grid

Personally I think the 50mm "standard" focal length (in this case equivalent after you factor in the 1.5x crop factor) is one of the most versatile focal lengths you can use when you decided to buy a prime lens.

Aberrations

Color fringing shows wide open but is quite mild and easily gone by f/4, not an issue here either. Again an excellent performance.The examples below show the mild color fringing on a high contrast target at f/2.4 and gone at f/4.

CA f/2.4

Lack of CA f/4

Flare is tame overall despite the lack of a lens hood of any kind. I'm very impressed with the performance here overall but its good to keep in mind that lenses of this focal length tend to do pretty good here in general.

Flare.. or rather, lack thereof.

Bokeh looks pretty darn good for a lens with an average magnification performance and a 6  blade aperture design. Likely this is due to the curved aperture blades creating more pleasing backgrounds in the larger aperture settings as shown by the samples below.

Bokeh f/2.4 (note circular out of focus aperture effect)

Bokeh f/4 (Note the curved blades on the aperture effect)

Pentax 21987 DA 35mm f/2.4 AL Lens for Pentax Digital SLR cameras

Maximum Magnification looks just slightly above average for lenses of this focal length unless you include the most very recent budget primes from other manufacturers that just hit the market- at this point its just an average performance. I'd have liked to see a better performance in this regard, perhaps at least matching the 18-55mm WR kit lens's 1:3 magnification ratio. As is though a pretty small area can be captured, then cropped if that is your desire. The high sharpness performance of this lens is certainly agreeable to this decision if you so choose to make it.

Real Life Maximum Magnification Sample

Real Life Maximum Magnification Sample II

Test Chart Maximum Magnification Captured Area (Full Test Chart is 20x30" wide)

FINAL Conclusion

Pentax 21987 DA 35mm f/2.4 AL Lens for Pentax Digital SLR cameras
On the whole the Pentax 35mm f/2.4 exceeds most of my expectations for a lens of this price new/retail. If you are shopping by looking at pictures and specs of it on the net, you'll never get the experience you'd need to truly appreciate this budget prime. I speak from experience here.

If you are comparing DSLR systems and looking at budget primes from all manufacturers, the Pentax may seem a bit high priced for the total package you get, but optically it may be the best of all the manufactures. Your emphasis for value is important to keep in mind, but if you are just looking for a lightweight excellent performing optic that stands up against optical tests very well, the Pentax 35mm DA f/2.4 is a good no brainer choice.

I liked this lens so much I decided not to return it to the retailer and use it almost daily on one of my own personal K5's. I do miss some of the features that Pentax is typically known for (weather sealing, quick shift focus) but not enough for me to return the lens. I can forgive it's plastic lens mount, and don't think a lens this light needs a metal one. I do enjoy it's low weight, nice sized focus ring, and its sharp as a tack, low distortion rendering much more than I miss some features.

As always be safe, and happy shooting.
-Carl Garrard

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