DA 20-40mm Ltd - anyone had a go yet?
The lens did seem to get a hammering from some quarters.. but there is a real world user photo thread somewhere on the US forum and the results didnt look that bad IMO
The price does seem steep... but depends how you look at it... if it was your "go to" lens.. perhaps it is fully justified
What would you do with you 31mm if you had the 20-40mm? Would you still use it sometimes for the superior IQ at that focal length?
I'd keep it. sometimes being limited on focal length chagnes the way you approch shots and they come out a different flavour. I've got zooms that cover everything from 10mm to 400mm, but I still use primes a lot.
Lenses: Pentax DA 10-17mm ED(IF) Fish Eye, Pentax DA 14mm f/2.8, Sigma 17-70mm f/2.8, Pentax-A 28mm f/2.8, Sigma 30mm F1.4 EX DC, Pentax-A 50mm f/1.2, Pentax-A 50mm f/1.4, Pentax-FA 50mm f/1.4, Pentax-A 50mm f/1.7, Pentax DA* 50-135mm f/2.8, Sigma 135-400mm APO DG, and more ..
Flash: AF-540FGZ, Vivitar 283
The 31mm will still be the go-to lens when I'm kicking about, or for trips that don't require absolute down-sizing, and the 20-40mm will be the "convenient" lens to go to, making my collection consisting of the 10-17mm fisheye, 31mm, 20-40mm and the 70mm ltd.
More than good enough for my needs.
In response to Chaude’s original post here are my initial thoughts on the new Pentax 20-40 after a short period of ownership:
Cost: £764 was SRS Microsystems’ special offer price that I jumped at. There have been many adverse on-line comments about the price of the lens but I’ll come back to that.
Size: We all know the DA Limiteds are tiny and the FA Limiteds less tiny. A zoom lens is inevitably going to be a little larger but that’s what the 20-40 is – just a little larger. In fact, it is very slightly larger than the FA 31mm Ltd but actually 60g lighter. To show the 20-40 in context the photo below shows (L-to-R) 50-135 f2.8, 17-70 f4, 20-40 f2.8-4, 35mm f2.4 and 70mm f2.4 Ltd.
Construction: Pentax Ltd-series lenses are renowned for their excellent build quality and the 20-40 is no exception. Simply put, it is superbly constructed and certainly to a higher standard than my 15mm and 70mm DA Ltds. When I bought the K-3 I willingly paid a lot of money for a DSLR that is incredibly well built and splendidly rugged. There are no current sub-£600 Pentax lenses built to that same standard and, indeed, very few at any price. Yes the DA* lenses are really nice and also weather/dust resistant but not built as well as the 20-40. The 31mm FA Ltd is a piece of precision engineering but it is not weather/dust sealed, nor are any other Ltd primes. It seems to me at the moment that the 20-40 is the only lens that matches the K-3’s very high standards of build and robustness and that, in my mind, surely justifies its cost.
Focussing: The 20-40 has an integral dc motor – I would imagine perhaps similar to the one in the 18-135. It is not SDM nor noisy screw-drive. As I’d dug out a bunch of lenses for the size comparison photo I thought I’d use them also for AF evaluation. Taking shots indoors and outside with close and distant subjects the 35mm f2.4 was consistently the fastest, albeit a little noisy. The 17-70 f4 SDM was not quite so fast but very quiet. Just slightly behind it came the 20-40 (we are talking milliseconds) which mainly performed well but was occasionally a little fidgety. It was also a little less quiet than the SDM system. Last by a long way was the 70mm f2.4 Ltd which very noisily twitched and fidgeted before locking on. Now, it didn’t do that with my K-5 and K-5 IIs so I need to look into that. Later moving into a fairly dimly lit room I found that the K-3 + 20-40 locked onto subjects I could barely see and with minimal fuss. No complaints there. The 20-40 employs Pentax’s Quick Shift system allowing quick manual adjustments to auto-focus. I should mention that the focus and zoom rings are very smooth and perfectly damped. The focus ring is a decent width and works a treat in conjunction with the K-3’s focus-peaking feature.
Aperture: I’ve read several on-line adverse comments about the variable f2.8 – f4 aperture. Really, that’s better than I get with the constant f4 17-70 and it’s only a stop slower than the 16-50 at the long end. F2.8 at the 20mm end is also better than the 21mm f3.2 Ltd prime manages. As far as I am concerned 20-40 is a very usable zoom range for street/travel photography and it can be backed up by wide-aperture primes if really necessary. And I’ll definitely still carry the 15mm and 70mm Ltd primes, if nothing else. The resolution of the 16.3MP K-5 IIs was more than satisfactory for most my photographic requirements so if I crop the K-3’s 24MP images to 16MP that’s better than adding a 1.4x TC to my lens (with no aperture penalty) and extends the 20-40’s long end to near 60mm.
Any new DA lens inevitably gets branded by some as a potential dinosaur ‘when Pentax FF arrives’. Well, if any manufacturer offers a FF DSLR set-up as compact and light as my Spotmatic with 50mm f1.4 ST I’ll bite their arm off but I’m not at all interested in the obese FF offerings from Cankon – they are fine for those who like to combine their photography with weight training.
Image quality: I started this post by saying it is a hands-on preview. Thanks to the dreadful weather we have been experiencing lately I’ve not had the opportunity to get out with the tripod to take meaningful test shots at various focal lengths and apertures. All I can say now is that nothing disappoints me so far in the many hand-held shots I have taken, but hand-held shots in gusting wind are not truly indicative of IQ. I’ll give the 20-40 a thorough testing when conditions improve.
I took a chance buying this lens and it might easily have been an expensive mistake, but it’s not. In fact I can very confidently say that I’m won over by it. I love the feel of it (quality engineering), the look of it and the way it balances so nicely on the K-3. It’s not everyone’s cup of tea due to its restricted zoom range but for anyone keen on street and travel photography, particularly in adverse climatic conditions, this one deserves serious consideration. I’d been finding that the weight and bulk of the 17-70 meant that I was often leaving the K-3 at home and instead taking out my little Fuji X-20. Since getting the 20-40 it is the X-20 that stays at home while the K-3 + 20-40 are regularly with me and have rekindled my enthusiasm.
I hope this might be helpful Chaude – but DO hang on to the 31mm .
Regards
Jim
I wonder, is the barrel distortion improved compared to the 21ltd, and also have you popped it on a film body to double check 35mm compatibility at various focal lengths?
I wonder, is the barrel distortion improved compared to the 21ltd, and also have you popped it on a film body to double check 35mm compatibility at various focal lengths?
Not sure how the barrel distortion might compare but hopefully I will be able to post a couple of 20-40 images @ 21mm focal length f2.8 and f5.6 so 21mm f3.2 owners can directly compare. I do not own a 21mm f3.2.
As regards use on a film body, I'm afraid I don't have a K-mount body - only older M42. Being a DA lens I would not be too optimistic about usefulness on 35mm SLRs.
Regards
Jim
The issue I have with it on my K5 is auto focusing. It's one of those zooms without an infinity stop. At room length distances focusing is accurate given reasonable light levels and contrast. By experiment I've found that the way to get consistent infinity (and close to infinity settings) at various focal lengths is to point at a distant object, manually defocus towards the short end, allow the motor to drive the lens into focus, then recompose and take the image. There's no hunting just straight there and stop. It appears that at telephoto focal lengths infinity is short of the centre of the infinity mark and at wide angle focal lengths infinity is beyond the mark.
When recomposing I often relax finger pressure and have to start the process again. Although then of course I could just switch to manual focus. Sometimes I twitch and trigger the shutter before I'm ready. I tried disabling focus on first press and using the AF button but I'm a left eye user and therefore my nose and right thumb clash. It's a pity the RAW/Fx button cannot be reassigned to AF. Cupping the lens with my left hand I could press the button with my thumb.
If you get one and take it on a trip anticipating doing sunset or sunrise shots you will also need a prime with fixed infinity stop.
Richard
Jim's review is very detailed and outstanding, mods, is this worth highlighting for other users/posted separately somewhere if Jim agrees?
Richard, thanks for the practicalities regarding the lens. I'm pretty sold on getting one so I shall see when my friend helps me to get one from Japan!
Thank you again.
Adrian
I have yet to verify just how good (or otherwise) the 20-40's IQ is. It needs time and conditions that I have struggled to find but I will post images as soon as I can. I also want to check first whether the 20-40 requires any AF fine tuning on the K-3 to be sure that autofocus is spot-on before taking test shots. I wonder how many of the self-styled 'reviewers' actually did that?
I was very interested in Richard's post. Firstly, the lens 'hood' provided with the 20-40 is indeed beautifully crafted in metal but really quite shallow. Richard's suggestion of using a wide-angle rubber hood to give more protection is sound advice, but just bear in mind that the wider the lens hood the more it will affect on-camera flash coverage, particularly for close-ups. Whether a stepping ring is necessary will depend on what filters you may already own. (Personally, I'll get a new 55mm polariser and then use my system filters with a 55mm adapter ring for anything else - ND grads, etc). As regards issues with infinity focussing, its not something I have noticed so far but I will certainly be checking for that.
Finally, as regards purchase in Japan I'd reiterate DrOrloff's warning re warranty. By buying from a Pentax Pro dealer in the UK I benefit from a two-year warranty - which is a lot of peace of mind. It's worth just double-checking what protection a Japanese warranty is likely to give you.
Best regards
Jim
http://www.pentaxforums.com/news/hd-pentax-20-40mm-review-posted.html
They were quite happy with it, 8.4/10 overall
10/10 for build quality
10/10 for bokeh (perhaps more surprising)
I too was a bit worried of swapping this combo for a faster shorter focal length and a slower longer focal length but I think the pros out weight the cons, also my 40mm is the fastest focusing lens I have owned.
I still haven't 100% made my mind up yet on the extra cost! but it does look mighty fine mounted on your K3
I am going to hold out I think until I can get hands on with it and to seeing some of your photos to compare IQ,
MattyH I think it's fair to say the 20-40 could replace your 21mm Ltd but I'd think twice about parting with the 40mm Ltd. I'm keeping my 35mm f2.4 because, although it's a horrible piece of plastic, it has pretty impressive optical performance even wide open. As found in the American review (link posted by Conqueror) sharpness suffers at the 40mm end of the 20-40. It really depends whether sharpness is critical to the shot. A camera with the resolution of the K-3 deserves the very best glass but I have found that for very many real-world subjects the 20-40's IQ is quite acceptable even at 40mm. This is borne out in some of the sample images in the review. Some forms of photography require critical sharpness but I'm more concerned with image subject and message, and I find this a useful zoom range. I'm not into pixel-peeping so if an image looks acceptable for its purpose at the largest size I'm likely to reproduce it then that's good enough for me.
I'd say it's pretty clear that the supplied metal lens hood is best replaced with a rubber hood as per posts above and the reviewer's findings. It's a shame because the supplied hood is a quality item but it's clearly a triumph of aesthetics over practicality.
Because of its high price it is well worth trying the 20-40 before buying if you can. I think you'll find there's something really special about holding and using the 20-40 - it harks back to the pre-plastic days, only better
Best regards
Jim
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437 posts
12 years
The price does seem steep... but depends how you look at it... if it was your "go to" lens.. perhaps it is fully justified
What would you do with you 31mm if you had the 20-40mm? Would you still use it sometimes for the superior IQ at that focal length?