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SMC Pentax-DA 17-70mm F4 AL [IF] SDM

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54 249,181 Fri November 30, 2018
Recommended By Average Price Average User Rating
76% of reviewers $469.59 7.66
SMC Pentax-DA 17-70mm F4 AL [IF] SDM

SMC Pentax-DA 17-70mm F4 AL [IF] SDM
SMC Pentax-DA 17-70mm F4 AL [IF] SDM

This wide-angle to normal zoom incorporates the new Pentax KAF3 mount, which uses SDM focusing technology but has no mechanical focusing shaft. Thus, it can only autofocus on Pentax digital SLRs that support SDM, including the K100D Super, K200D, K10D, K20D, and later models. On older cameras you must focus manually.

SMC Pentax-DA 17-70mm F4 AL [IF] SDM
©, sharable with attribution
Image Format
Lens Mount
Pentax K
Aperture Ring
Automatic, 7 blades
17 elements, 12 groups
Mount Variant
Check camera compatibility
Max. Aperture
Min. Aperture
AF (in-lens motor)
Min. Focus
28 cm
Max. Magnification
Filter Size
67 mm
Internal Focus
Field of View (Diag. / Horiz.)

APS-C: 79-23 ° / 70-19 °
PH-RBM 67 mm
Lens Cap
Weather Sealing
Other Features
Diam x Length
75 x 93.5 mm (3 x 3.7 in.)
485 g (17.1 oz.)
Production Years
2008 to present (in production)
$326 USD current price
Engraved Name
smc PENTAX-DA 1:4 17-70mm AL [IF] SDM
Product Code
User reviews
In-depth review
Lens mount has a rubber gasket, though the lens is not otherwise weather sealed.
Two aspherical elements.
No autofocus on older bodies (*istD series, K100D, K110D, and film).

Supersonic AutofocusQuick ShiftInternal FocusingAutomatic ApertureAPS-C Digital Only
Purchase: Buy the SMC Pentax-DA 17-70mm F4 AL [IF] SDM
In-Depth Review: Read our SMC Pentax-DA 17-70mm F4 AL [IF] SDM in-depth review!
Sample Photos: View Sample Photos

Add Review of SMC Pentax-DA 17-70mm F4 AL [IF] SDM Buy the SMC Pentax-DA 17-70mm F4 AL [IF] SDM
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Veteran Member

Registered: June, 2010
Posts: 737
Lens Review Date: January 18, 2013 I can recommend this lens: Yes | Price: N/A | Rating: 7 

Pros: overall sharpness, colour, SDM, build, constant f4
Cons: manual focus, little softer at 70mm, AF at 70mm, SDM
Sharpness: 8    Aberrations: 8    Bokeh: 9    Autofocus: 5    Handling: 8    Value: 8    New or Used: Used    Camera Used: k-5   

This is my workhorse lens, its quite versatile, constant aperture is very convenient and is reasonably sharp, although not up to standards set by limiteds. But nobody expects this lens should compete with limited primes for IQ.
On its own it is quite sharp, maybe not as sharp as DA 50-135, but close enough. For best iq, stopping down to f8-11 is necessary. Zoom range is quite useful for all-round purposes, close focusing is a nice feature too. Build quality is somewhere between star lenses and DA16-45, better than DA16-45 but not quite up to build quality of DA*. The mount is weather sealed, but the lens itself is not. It handles CA better than DA16-45, sharpness and colour rendering is moreless the same. AF is quite slow and sometimes it cant lock focus at 70mm which is real downside of this lens. Otherwise it is quite good allround lens.
New Member

Registered: December, 2012
Posts: 17
Lens Review Date: January 18, 2013 I can recommend this lens: No | Price: $400.00 | Rating: 1 

Pros: None
Cons: It doesn't focus
Sharpness: 7    Aberrations: 7    Bokeh: 7    Autofocus: 1    Handling: 1    Value: 1    New or Used: New    Camera Used: K-5   

It doesn't focus at all.
Senior Member

Registered: November, 2012
Location: London
Posts: 157
Lens Review Date: November 14, 2012 I can recommend this lens: Yes | Price: $600.00 | Rating: 9 

Pros: sharp, good macro, good handling, quick af, constant f4, good colors
Cons: none, could be about $50 cheaper imo.
Sharpness: 9    Aberrations: 10    Bokeh: 10    Autofocus: 8    Handling: 9    Value: 9    New or Used: New    Camera Used: K5iis   

Firstly, let me say that the autofocus on this lens is near silent, there is a tiny high pitched sound but that is how sdm works, duh. This lens is a workhorse, I can get good macros with good bokeh out of it, the zoom ring is nicely damped, sharpness is quite good even at f4 and at 17-60mm the sharpness is very good, it is so much better than my Tamron 17-50, it is a little soft at 70 but at f6.3 it is pretty ok. The SDM is quick and quiet and although the Sigma 17-70 is cheaper, this is sharper at every focal length and is smaller. It could be cheaper but it is still good value.
Lens Review Date: September 29, 2012 I can recommend this lens: Yes | Price: $570.00 | Rating: 8 

Pros: Focal length, constant aperture, accurate AF but see cons, no zoom creep, bokeh at 70mm f4, decent image sharpness, size and weight, very nice lens hood with little window for polarising filters
Cons: Compared to Canon EF 17-70mm f4 L USM and EOS 40D: turning AF ring extremely annoying and touching it can damage the AF motor during AF, slower AF with noticeably louder (high pitch) AF noise, no zoom lock when you walk; very likely that the lens will ext
Sharpness: 7    Aberrations: 8    Bokeh: 8    Autofocus: 5    Handling: 8    Value: 7    New or Used: New    Camera Used: Pentax K-5   

Recommended but with a few issues.
Forum Member

Registered: June, 2012
Posts: 80

2 users found this helpful
Lens Review Date: September 9, 2012 I can recommend this lens: No | Price: $500.00 | Rating: 2 

Pros: IQ "CAN" be excellent when stopped down a bit
Cons: AF accuracy - eventual failure
Sharpness: 9    Aberrations: 9    Bokeh: 8    Autofocus: 3    Handling: 6    Value: 4    New or Used: New    Camera Used: Kx, K-5   

This COULD have been a great lens. Optically the 17-70 has the chops to be an excellent all-purpose wide zoom but it shows a clear "lack of focus" on the part of management at Pentax. At times I really like this lens. At other times I hate it.

UPDATE: I hate it. See below for reasons you should avoid it.

The Good...
1. This lens can turn in great wide shots at 17mm and is pretty good below 50mm when the AF is spot-on. As mentioned, toward 70 is gets softer but the change is not drastic. When it nails focus, it is quite sharp comparing well to some of my wide primes!
2. Nice saturated color from wide open.
3. Flare resistance. No problems with flare even without the hood!
4. No serious issues with CA or PF.
5. Not too heavy
6. Haven't had an SDM failure, yet. -- UPDATE: Of course I have. :-)

The Bad...
1. This lens can turn in out of focus shots at almost any focal length in almost any light. Between 50 and 70 in lower light it can sometimes lock focus so comically bad that the whole frame is simply a blur! At wide angles taking landscapes one must be very careful to check for critical focus after shooting lest the lens go past infinity and lose sharp focus everywhere. Acts the same on the K-x and K-5. Frankly for wide landscapes, use LV and pre-check focus or better yet carefully use MF. It can easily look good on the LCD only to show poor focus later on the computer. Infuriating!

2. The comically short focus throw with almost zero damping makes AF inaccurate IMO because they were trying so hard to give the weak SDM motor a shot at keeping up with the AF speed of the screw drive. Repeatability is also low. Take the identical shot of a clearly defined, unambiguous subject 10 times and get all sorts of variation. Your AF system is only as good as the AF positioning system in the lens you're using and this just doesn't cut it. The short focus throw also makes manual focus so touchy as to be almost useless.

3. The horrible KAF3 mount decision... While most SDM lenses have SDM and screwmount drive as a backup (KAF2) the 17-70 suffers with the cost-reduced KAF3. When the SDM goes, you're dead in the water. If this were KAF2 I would have covered the SDM contacts long ago. There was no excuse for this cost reduction on a $600 lens.

4. More evidence that Pentax didn't know how to position this lens? Partial weather sealing? Yeah there is a nice big weather seal on the mount but it's not a WR lens and apparently lacks the other water and dust seals. Huh???

5. SDM reliability -- There is a high chance that this lens will fail you and you'll be stuck with an expensive repair that may or may not be a long-term fix. IS IT WORTH IT?

The 17-70 would be a superb lens with a screw drive (or maybe the new DC drive) and a longer focus throw. Maybe a 17-70 mkII.

UPDATE: After another weekend outing with this thing I have to downgrade another point. Unless you chimp every wide shot with this thing... don't count on focused photos. Take multiple shots purposely throwing focus out in between shots to give the AF another try. This should NOT be necessary. My other lenses work quite well compared to this.

More and more the lens simply sticks and refuses to focus at all until it gets some "exercise". This is the classic symptom for SDM failure which will cost $200+ to fix. Pentax did themselves a great disservice by being cowards and never coming clean about the SDM issue with their loyal customer base. Instead of supporting their product they lied and hid from a bad design hoping the problems would just go away. Now SDM lens customers must question if the design is actually fixed or if a lens sent for repair will be repaired with a fixed motor design or just another bad motor destined to fail. It's fairly clear that the new DC motor lenses are an answer to the high failure rates of the SDM's. One might ask why the new DC motor if SDM failure rates were within the acceptable range. Do yourself a favor, don't buy an SDM lens period.
New Member

Registered: April, 2010
Posts: 5

2 users found this helpful
Lens Review Date: April 20, 2012 I can recommend this lens: Yes | Price: $425.00 | Rating: 10 

Pros: zoom range, decent IMQ, near silent AF
Cons: AF good Kr,K5 :(
Sharpness: 10    Aberrations: 9    Bokeh: 9    Autofocus: 10    Handling: 9    Value: 10    New or Used: Used    Camera Used: Kr   

Before I used it with K10, K7. Very difficult to focus on 50-70
But is it really Kr is no longer effective in 50-70 hunt phenomenon. Perhaps because of K7 AF not as good as I Kr and previous reviews are probably 5 points for K7 but perhaps it is 10 pointswith Kr.
ALL IN ONE a lens from landscape, portrait ......
( Sorry about my english )
ảnh nguyên gốc JPG - resize

Em cu của Khánh_Zui, trên Flickr

Anh Phương của Khánh_Zui, trên Flickr

17-70 của Khánh_Zui, trên Flickr

Ngọc Béo của Khánh_Zui, trên Flickr

Food của Khánh_Zui, trên Flickr
Veteran Member

Registered: October, 2007
Location: Port Townsend, Washington State, USA
Posts: 3,659
Lens Review Date: April 17, 2012 I can recommend this lens: Yes | Price: $507.00 | Rating: 9 

Pros: F4,useful range, no creep, size/weight, quiet
Cons: Hood gets in the way of AF assist light
Sharpness: 9    Aberrations: 9    Bokeh: 9    Autofocus: 10    Handling: 8    Value: 10    New or Used: New    Camera Used: K5   

The background i read on this lens is that it was built as an extension of the very popular DA 16-45. I do a fair amount of photography for a live performance theatre (plays), and i've always had to change out my Tamron 28-75 f2.8 when i had a need below the 28. Although this lens is not as fast as the Tamron, the F4 is suitable throughout its range, perhaps slight softness at the 70mm end. Except for dark scenes, this will give me great flexibility in shooting for most plays.

Lens creep is a real anoyance to me and its good to see that this lens zoom is so well damped that is has none.

The lens review site,, complimented it highly:

The Pentax DA SMC 17-70mm f/4 AL [IF] SDM is undoubtedly the most desirable standard zoom lens in the current Pentax lens lineup. The resolution characteristic is very good without any significant weakness.

The review was dated Dec 2008 and was done on a K10. I've noticed that on the lenses retested by on a 16 mp K5, there is often an increase in resolution by up to 19%.

I know that in some of the earlier reviews, some problems with the SDM were encountered. Latest polls on PF shows that there is a marked decrease in SDM problems across the board. The plus side of SDM is the lenses are very quiet when shooting at events. And this particular lens has the fastest focusing speed of any of my, now 3, sdm lenses.

I'm going to enjoy this lens a lot.!
New Member

Registered: April, 2012
Location: Independence, MN
Posts: 1

1 user found this helpful
Lens Review Date: April 3, 2012 I can recommend this lens: Yes | Price: $480.00 | Rating: 10 

Pros: great range, quality feel, quiet, vibrant
Cons: no Weather proofing
Sharpness: 10    Aberrations: 10    Bokeh: 9    Autofocus: 10    Handling: 10    Value: 10    New or Used: New    Camera Used: k5   

If this had weather-sealing and a bit more "bling", it would be a DA*. I might say if it was a bit faster too, but Pentax's current short/mid zoom DA*16-50mm doesn't look that great until it is at F4 anyway. I really debated between the DA17-70 and the DA*16-50. I own several DA*'s in other ranges and I like the little "extra" they come with.

Ultimately, without the WR and the Gold Band and perhaps the 2.8 or 3.5 designation that would attract more attention, this lens is simply good, excellent even. And 20mm more reach is greatly appreciated, especially with portrait work. Pentax has 5 short zooms. Their Kit zooms are better than expected. And we are programmed to presume the DA*16-50mm is the one we should all be saving for. This DA17-70mm, especially at the $480 I paid, is the best choice. Not just for the money, it is the best choice period. It is so consistant, center to edge and in different light. The DA*16-50 needs to be compensated for, the DA17-70mm you just shoot.

The Sigma 17-70mm and Tamron 17-50mm each have some noteworthy strengths, but some negatives as well. Of all 7 choices I know of that you can hang on the front of a K5 and capture the midrange zoom, this is the best. If you don't have to have weather-sealing, buy it; enjoy it. Don't let anyone make you feel bad!

Registered: May, 2011
Location: Pittsburgh,PA
Posts: 321
Lens Review Date: December 31, 2011 I can recommend this lens: Yes | Price: $470.00 | Rating: 9 

Pros: Great Glass, Sharp, Extremely useful focal range, Excellent flare resistance
Cons: A bit slow.
Sharpness: 8    Aberrations: 8    Bokeh: 7    Autofocus: 10    Handling: 10    Value: 9    New or Used: New   

At the discount price I purchased, it's definitely worth it. Excellent walk around lens.

IMGP1190-new by dr_romix, on Flickr

IMGP1173-new by dr_romix, on Flickr

IMGP1184-new by dr_romix, on Flickr

DA 17-70 Direct jpeg no PP. Excellent low light focus with K-5. This is around mid night -10C.

Taken around mid-night. Temp -10 C, Pentax weather-sealed capability quite useful. by dr_romix, on Flickr
Inactive Account

Registered: September, 2010
Location: Burley, Idaho
Posts: 6

3 users found this helpful
Lens Review Date: December 3, 2011 I can recommend this lens: Yes | Price: $480.00 | Rating: 10 

Pros: SHARP!!! Quiet with Good Range and Close Focus.
Cons: Focusing ring rotates
Sharpness: 10    Aberrations: 10    Bokeh: 10    Autofocus: 10    Handling: 10    Value: 10    New or Used: New   

I've been reading other reviews of this lens and I can't believe we're talking about the same lens. I think it's the best normal range zoom. I've used almost all the others, Pentax, Nikon, and Canon none were better. I've taken portraits and flower pictures at 70mm f4 and they are tack sharp. I've had one problem with the focus but that was after I stood in a blowing rain storm taking a picture of a mountain lake. I sent it to pentax and it came back better than new. I use this lens for about 85% of my pictures. I've been a professional photographer for over 40 years and I'm telling you this lens can do it all. I know Pentax has a 16-50mm f2.8 that a lot of people like and it is sharp but 50mm are you kidding? I owned a Canon 17-50mm f2.8 and I almost gave it away, too short for weddings and not all that sharp. I know the SDM gets a bad rap but other Pentax lenses have the SDM focusing like all the Star lenses. I have not tried the new 18-135mm yet. I do need a weather proof lens that is sharp. If the 17-70mm lens was wearher proof it would be perfect. Once again I'm telling you this lens is Sharp!!!!!!! See Later Comments about focus problems again, I'm not so smilely now. When it works it's great but.........
Forum Member

Registered: March, 2010
Location: Andalucía and the U.K.
Posts: 63

1 user found this helpful
Lens Review Date: October 16, 2011 I can recommend this lens: Yes | Price: $500.00 | Rating: 9 

Pros: Useful zoom range, swift and silent AF, nice colours
Cons: Weak corners at 17 and at 70mm, price?
Sharpness: 8    Aberrations: 9    Bokeh: 8    Autofocus: 9    Handling: 9    Value: 7    New or Used: Used   

I suppose your opinion of this lens depends on the copy you have. Mine has never had any focussing issues between 50 and 70mm and the SDM has performed flawlessly. For me it's always been a very useful and reliable performer.

In terms of IQ, autofocus and range it's a definite step up from the kit lens. However, the question is whether it's worth the extra cash. In the UK this lens is retailing for about £400, nearly £350 more than the 18-55. You get an extra 1mm and the wide end, an extra 15mm in length and the autofocus is swift and silent (at least in my example). The overall IQ is better, but it's still a zoom. So is it worth the extra? I think that depends on your specific needs, expectations and of course the size of your wallet.
Veteran Member

Registered: November, 2006
Location: Singapore
Posts: 3,202

1 user found this helpful
Lens Review Date: October 3, 2011 I can recommend this lens: Yes | Price: $340.00 | Rating: 9 

Pros: SDM silent focusing, excellent IQ, great color, good quilt quality
Cons: a little bit heavy and big for an F4 lens, focusing ring too loose
Sharpness: 9    Aberrations: 9    Bokeh: 8    Autofocus: 8    Handling: 8    Value: 8    New or Used: Used   

I think this lens got some bad reviews because of some bad copies, especially the AF problem near the tele end on some copies. I've had 3 copies of this lens, sold the first one in favor of the DA*16-50. Then got one back for the range, but returned it right away due to focusing issue between 50 to 70mm. Just got another copy, no focusing problem through out the whole range.

Overall the IQ is very good. It's pretty sharp w/ great color. Bokeh is good for a zoom lens, the zoom ring is smooth and feels solid. The lens can focus very close, much closer than most other zoom lenses,. very fun to use if you like to shoot some closeups once in a while.

I've had the DA18-135 DC lens too, other than focusing speed and center sharpness, I didn't like that lens as much as the DA17-70. The pictures from 18-135 just feel not as vibrant, colors are not as punchy. Given the choice again, I'd still go for the DA1770 (assume it has no AF issues).

If you got a good copy (no SDM or AF issues), you'd be very happy w/ the lens.
New Member

Registered: May, 2011
Location: HCM
Posts: 1
Lens Review Date: August 20, 2011 I can recommend this lens: Yes | Price: $500.00 | Rating: 9 

Pros: Sharp, Good range
Cons: Low AF forcus
Sharpness: 8    Aberrations: 9    Bokeh: 8    Autofocus: 7    Handling: 9    Value: 9   

This len is better than Kit, shape, good bokek, can compare image quality with 24-105 L Canon. But autofocus is very low, a little bit hunt at 70mm.
However If you dont have enough money for DA*, that's a good choice. Dont complaint to much if we dont have money.
Site Supporter

Registered: October, 2009
Location: Alberta, Canada
Posts: 305

1 user found this helpful
Lens Review Date: August 14, 2011 I can recommend this lens: No | Price: $500.00 | Rating: 7 

Pros: Versitile zoom range, Image quality, moderate price
Cons: SDM failure, problems focusing above 60mm
Sharpness: 8    Aberrations: 10    Bokeh: 7    Autofocus: 5    Handling: 9    Value: 5    New or Used: New    Camera Used: K-5   

I would rate this lens much higher if it were not for the SDM failure that was repaired on warranty (and quickly too) and also the problems with focusing above 60mm. That problem was originally also repaired on warranty but it has developed again so I'll have to send it back to Pentax. I would think it was just my bad luck but I've read here where others have experienced the same problem.

If I ignore the above two problems I would give this lens an overall score of 8.6 or so. The zoom range is very convenient making this an ideal walk around lens. The quality feel is certainly there as there has been no zoom creeping. When the SDM works it is fast and silent. As to image quality, I have never noticed purple fringing so it seems to handle CAs excellently. There is some vignetting, which is especially noticeable when a filter is attached.

Once the lens was returned I will used it again but the problem started around six or seven months later. The problem with not locking onto focus at zoom ranges approximately above 60mm. I had it fixed again but this time it was off warranty. It cost well over $200 for repairs and shipping. Once they fixed it I decided it had two repairs too many and put it up for sale with full disclosure of the repairs. The new owner might have a problem free lens for years or it might last him one year before the problem begins again; I don't know but I'm glad I don't own it. I moved to an 18-135 which is much lighter, very fast focusing, and quiet. As an update, I've used the new 18-135 for about a year with no problems. As a result, I can't recommend the 17-70 even though it was a very nice range and had the constant aperture. I hope that others have better luck with this lens.
Site Supporter

Registered: January, 2008
Location: Michigan
Posts: 397

1 user found this helpful
Lens Review Date: March 3, 2011 I can recommend this lens: No | Price: N/A | Rating: 5 

Pros: Very high image quality when focus spot on. Good focal range.
Cons: Unreliable AF. Can't lock focus at long end.

This lens has potential to make you very frustrated. One one hand, if focus is spot on, image quality is very high. Color is pleasing. On the other hand, achieving focus is not easy, at least for my copy. At many occasions, it can't lock focus at all @50mm~70mm focal length - it hunts all the time. I suspect my copy is having faulty SDM motor or internal mechanism. I concur with another reviewer here that its SDM motor has design problem. Or problem might only happen on some copies (I'm not sure), but it is enough to make you wonder whether you should trust SDM. I have many Pentax screw-drive AF lenses. None of them makes me so worried about their AF.

If the lens does get the focus right, it is very sweet. Resolution seems to be very high. Color is very pleasing. The focal range is very useful. These make me even more frustrated about this lens - should I bring it when I take pictures? I end up to bring another lens along with it all the time lest this lens lets me down at importatnt moment. But this lens is supposed to be so versatile that you can bring it alone, right?
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