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Posts tagged “pentax da 20-40mm

PENTAX DA 20-40mm F2.8-4 ED Limited DC WR review.

Pentax DA Limited series are special lenses, especially the focal lengths and their maximum aperture opening, but they are also small and full metal lenses (even the front lens cap) like the old days !!! They are not for every one, if you need a fast lens you will have to look elsewhere, there is already many choices in standard lenses, the Limited are about small size, craftmanship and IQ, by that i mean not only sharpness, in fact they are not always the sharpest lenses you can buy for a certain focal length but they have character. Pentax really kept the phylosophy of the DA Limited line with that zoom and as a bonus it looks sexy with that Takumar type zooming ring !

I’ve been waiting for that Limited Zoom lens since Pentax put it on their roadmap some years ago, it’s finally here and as a bonus it now have the benefits of the new HD coating, WR and the newer DC motor. The lens also incorporates an ED (Extra-low Dispersion) glass and a super-low-dispersion glass element.  So as soon as i could Pre-order one i did it and waited anxiously for it to be delivered at my door 🙂

For me, the “slow” maximum aperture is not important since i wanted it for it’s small size and because i will use it mostly stopped down for landscape. It fits in my goal of building a smaller kit for travelling or when i don’t want to carry a heavy camera bag. It will replace my FA20mm/2.8 (255 gr.)  and DA 35mm Macro Ltd (215 gr.), less space and weight but with the versatility of a zoom lens. It will do a great combo of Weather resistant lenses with my DFA 100mm Macro WR and DA*50-135mm, with those 3 lenses i can cover most of my needs for general nature photography.

Here it is, the new kid on the block in a family portrait of my zoom lenses.  You can see the size difference here compared to the Canon 15-85mm. Canon 15-85mm/3.5-5.6, Pentax HD DA 20-40mm/2.8-4.0 WR Limited, Pentax DA*50-135mm/2.8, Canon 70-200mm/4 L

Here is the Maximum f/stop for each focal length setting on the lens:

– 20mm: f/2.8

– 25mm: f/3.5

– 30mm: f/3.5

– 35mm: f/4.0

– 40mm: f/4.0

Some might argue that this new Limited lens is not wide enough, well, there is certainly better lens for WA shooting. I already own a Canon EF-S 15-85mm/3.5-5.6 IS when i need more range in a zoom lens, but there is some tradeoff ….. size and weight ! The Canon weights 575 gr. (no hood) and takes 72mm filters, compared to the Pentax DA 20-40mm Ltd at 291 gr. with the hood and takes 55mm filters. BTW the Canon is a crop sensor lens, not a FF. They don’t fill the same niche and purpose and that’s why i own both of them.

The lens feels very good in the hand, the cold and solid feeling of metal is such a joy. The lens hood is made of metal and screws into the filter thread and as a bonus the metal lens cap fits on the lens hood which is great since your hood is always mounted on the lens and ready to shoot. The zooming ring have more resistance than i like on a lens but this is a positive thing, you will never experience zoom creep in the field, but the focusing ring is smooth.

The DA 20-40mm Ltd balances very well on my K-01, it’s like they’ve been made to work together. Both with high quality materials and fun to use in the field. With the DA 20-40mm you will have to shoot more like if you had a prime 30mm lens but with some room on both side because of the limited range, so you will need to walk more around your subject (which is not a bad idea). With my Canon 15-85mm i tend to zoom in or out unless i crank it to 15mm when i want the maximum FOV.


This Pentax lens have 9 elements in 8 groups and incorporates the new HD coating. The lens hood is small, so Pentax is really confident in their new Coating! Didn’t had a chance to really try the flare resistance of the lens but here is the only photo that somehow show how the lens performs.

No sun in the shot but we can see the highlights coming between the wooden wall, good for looking for Aberrations.

Here is a crop of the previous shot, the only part that i can see some aberrations.

Pentax K-01, at 20mm at f/8, ISO 1000, handheld with SR.


Something for the Pixel Peepers now, sharpness is not everything but it certainly is a big part of the equation especially when you pay nearly a 1000$ for a lens.  The corners at 20mm at f/2.8 are not the best but unless you need that kind of settings at 20mm there is better lenses that would fit your shooting style.  It was certainly designed for landscape photography where you need to stop down for DOF. I use it at any focal length and any aperture from f/2.8 down to f/11-16 if necessary. So apart from the corners at 20mm i have no concern about the sharpness of that lens.

Here is a 100% crop of a photo taken at 38mm at f/4, not too bad !


Every lens is a compromise, here Pentax made it smaller and lighter so they had to do some compromise. The good thing is that they did some compromise in a place easy to correct in the camera or in PP. They left some vignetting especially at 40mm where even stopped down there is still some vignetting, see below for an example.

It was raining and a thick fog was covering the landscape, a good test for the WR and SP coating !

K-01, at 40mm, ISO 100, f/10, RAW, Tripod.

This is the photo just above without any PP directly from the RAW file, you can see some vignetting, taken at f/10 at 40mm but it was easy to correct in LR.

Here is another example of the vignetting present at 40mm, this time near the minimum focusing distance of the lens. I did no PP on this one posted here, but in LR the vignetting was easy to correct.

K-01, DA 20-40mm at 40mm, f/13, tripod, RAW.


The lens by itself already have a minimum focusing distance of 28cm and gives a repro ration of 1:5. I will probably be the only one to try this, but i put my Extension tube of 25mm on my DA 20-40mm Ltd to see how it would do as a close-up/Macro lens if needed in an emergency.  I photographed the same scene with my DFA100mm Macro WR just to have a reference for IQ, i tried to keep the same composition and the same plane of focus. Like usual i used a tripod and 2 second delay in RAW with my K-01. Below are some 100% crop with no PP or sharpening, not bad at all, will have to test it in the field.

The subject, with DA 20-40mm at 40mm at f/11.

DA 20-40mm at 40mm at f/8.

DFA 100mm Macro WR at f/8.

DA 20-40mm at 40mm at f/11.

DFA 100mm Macro WR at f/11.

Some Close-up photos taken in the field, i wasn’t expecting that Limited zoom lens to be able to do that good at the minimum focuing distance even with an Extension tube it still deliver very good IQ.

Close-up taken in my garden to test it outside, at the minimum focusing distance of the lens with some cropping for composition purposes.

K-01, at 40mm, ISO 100, f/14, tripod, RAW.

It’s been raining with warm temperatures for the last 3 days now and there is water on the ice of the ponds and lakes. The following photos were taken at 40mm, the DA 20-40mm works pretty well as a “Close-up” lens. 

This one near the minimum focusing distance of the lens.

K-01, at 40mm, f/13, tripod, RAW.

K-01, at 40mm, f/13, tripod, RAW.

100% Crop of the shot above before any PP, directly from the RAW file in LR.

Some photos taken in the field.


One of my first shots in the field while it was snowing.

Pentax K-01 with DA 20-40mm Ltd, at 38mm at f/11, ISO 125 tripod, RAW.

Old Canal on a cold morning.

K-01 at 24mm at f/16, ISO 100, Tripod, RAW.

Sunrise on a Lake taken on my way to work.

K-01, at 20mm, f/13, ISO 100, Tripod, RAW, Graduated ND Filter.


For me that’s a lens that fits my kit i wanted to have for my Pentax system, will probably add a smaller and lighter WR body (K50) to complete my lightweight and WR kit along with my K-01. It’s not a lens for everybody and will never be and continue to be a “controversial” lens in discussions on Forums. Pentax lens designer had to made some compromises to come up with a small and lightweight Limited Zoom lens, they did where it didn’t affect the IQ. Vignetting (which is easily corrected in the camera or in PP) and they made it an f/2.8-4.0 lens instead of a constant f/2.8 lens, for a lens that is primarily directed to the outdoor (Landscape) photographer, those compromises are worth it to have a lighter kit, as a bonus the lens add WR, HD coating and DC motor.

It might become a legendary Pentax lens, as  the 1st Zoom lens in the Limited series, with it’s small, lightweight, all metal build, WR and very good IQ, it certainly deserve it.

Old Canal on a cold morning.

K-01, DA 20-40mm at 40mm, at f/13, ISO 100, RAW, Tripod.


Weekly photo, 05 January 2014

It’s been a very cold week, nights temperatures were ranging from -20C to -28C ! Good for forming ice on rivers and Waterfalls. This is a shot of an old Canal close to my home, it’s been closed to navigation for many yeasr now.

Pentax K-01 with DA 20-40mm WR Limited, tripod.