Tamron AF 28-75mm f/2.8 SP XR Di LD Aspherical (IF) Lens for Pentax Digital SLR Cameras (Model A09P)

The Tamron 28-75 has become somewhat of a legend due to its phenomenal image performance for the price. Yet, when you take price out of the equation, this lens still holds its own surprisingly well against the top-dogs from Canon and Nikon costing anywhere from two to four times the price of the Tamron. So far, I've found this lens is consistent with what I've been hearing across the Internet: image quality is at a professional level.The lens looks and feels like most Tamron lenses I've seen, plastic but reasonably well built. The zoom ring is at first a little snug in operation, but I suspect it will loosen a bit over time. The focus ring rotates during automatic focus operation, but that's really a non-issue in my view of things. However, everything still feels generally solid and of quality construction, in contrast to the loose and rattling lens barrels, zoom and focus rings of the Pentax "kit" lenses: the 18-55 and 50-200. Autofocus operation with the 28-75 is a bit on the noisy side, but I've found it to be fast enough so far. What's most important, it's been spot-on in typical shooting situations (a welcome relief to the Pentax DA* 50-135 f2.8 I had to return due to poor autofocus performance and resultant soft images). Some comparison shots between this lens and the Tamron 18-250 taken in the 28 to 75mm range show that the 28-75 is clearly a sharper lens and maintains that sharpness nicely boarder-to-boarder. The 18-250, my basic walkaround lens, is a strong performer in that lower range, but it is simply outclassed by the 28-75. Contrast and color saturation is also superior to the 18-250. Interestingly, color tone with the 28-75 looks to be ever so slightly warmer. I've found that CA (chromatic aberration - purple fringing) is present in some rare shots near the boarders such as with the edges of overhead florescent lighting in a gym where that lighting is overexposed in contrast to the rest of the picture, but I haven't seen it appear in many other situations where one would expect to find purple fringing. At f2.8, I've found that this lens still produces impressive images, especially at the long end, but not quite up to the sharpness at f4.0 and higher. So far, I haven't really noticed any issues with vignetting or distortion.The 28-75 is also a full-frame lens, meaning that it is designed for cameras with a 35mm film frame-sized sensor, but it will also work on the smaller APS-C sensor of the Pentax D-SLRs (dedicated APS-C lenses such as the Tamron 18-250 will not work properly with a full-frame sensor). The positive of using a full-frame lens with the APS-C sensor is that the smaller sensor benefits from being more in the lens' "sweet-spot, " that is, the potentially softer/distorted boarders seen by a full-frame sensor for a particular lens are just outside the reach of the APS-C sensor. Kind of makes one wonder why all D-SLR lenses aren't full-frame.Considering the limited lens options for Pentax D-SLR owners, especially higher-end products, this is certainly the lens to have. While the Pentax APS-C factor of 1.5x, and an effective focal length of 42 - 112.5mm is perhaps not quite wide enough for some shots, it does, however, work great for general use including portraits and low-light interior shots without flash. A nice surprise I found with this lens is that it has an aperture ring which means I should be able to use it on my old Pentax ME Super film SLR for a true 28-75mm focal range. As I continue to be impressed with the 28-75, I'm hoping that the new Tamron 70-200 f2.8 due out in a few weeks will be in the same league as this legendary lens bargain.

*******PLEASE READ UPDATES AT THE BOTTOM OF THIS REVIEW TO LEARN WHAT HAS HAPPENED WITH MY LENS AT TAMRON***********I bought this lens after reading so many positive reviews from Amazon customers. However, I did note on a multitude of websites such as slrgear.com, dpreview, and photozone.de that these lenses have quality control issues. These websites all had to use multiple lenses from Tamron before receiving one that worked good enough to test. When the lenses work, they are great. Unfortunately, I RECEIVED 3 BAD COPIES!!!Lens 1------This lens, though tac sharp, was completely unacceptable. Randomly, with all camera settings the same, the aperture would get stuck and overexpose pictures to the point of a white out. When this happens, I would have to zoom in or out and return to the same position, then the lens would work again. Then, after 20 more shots, the over exposure would occur again. Needless to say, I returned it.Lens 2------This lens blurred randomly through out different points in the zoom range. I tested it side by side with Lens 1 and Lens 3, the blur was outrageous and f2.8 to f5.6 was incredibly poor.Lens 3------This is the lens that (unfortunately) I decided to keep. This lens has the least amount of issues. Unfortunately, I did not notice its problem until too late, particularly because the error with the lens is not readily noticeable and I suspect the way it behaves is probably the same that so many customers have not yet noted and are not examining their pix close enough to see this behavior. The behavior/issue is this...Lens 3 between 28mm and 45mm focal lengths has a left side blur at the lower left quadrant of the pix. It is most noticeable in peculiar and very particular settings.Setting 1 - shooting less than infinity focus at a 45 degree angle downward at a target low to the ground (example, my cat on the floor). I am holding the camera standing up, aimed down at 45 degrees. The cat is center. Take the shot, review, and the carpet is completely blurred on the left side. Stopping down to f8 helps, but it is still very bad up to 5.6 stops. Who expects to shoot at f8 indoors at close distances any way??? You should be able to shoot at f4 minimum, let alone f2.8.Setting 2 - same 45 degree angle shooting scenario, this time outdoors in a landscape shot of flowers focus less than infinity. The grass, just like the carpet, is a complete blur on the left lower quadrant. Shot at f4 to f8, blur still persists at any setting, just a little better at f8. Then again, I should easily be able to shoot at 4 stops, instead of stopping down to 8 stops.Setting 3 - This is the most critical for the issue really becomes very evident when shooting at infinity focus from 28-45mm at 2.8 to f8 stops. I shot a row of trees straight on at f5.6 to f8 (and just to test, I stopped down to f10 to f16 which did not make a difference). The trees were blurred on the left, and more so, the grass was completely blurred into a green slur. This happens every time.Setting 4 - shooting low to the ground (about 2 to 3 feet off the ground) aimed down range about 15 feet or more. Again, grass on the right of the pix is clear and sharp, left side is a total mess.Now, with extreme inconvenience, I have to mail in my lens on whim of hope that the blur can be fixed, though so many have complained Tamron was not able to fix their blur issues. I have had the lens for a little over a month, and now I am stuck. All I have to say is this: If my lens does not come back fixed I will NEVER, EVER give Tamron another dime or even a thought of their products in the future. It is completely unacceptable to have purchased 3 of the same product and have 3 outright defects where all the lenses behaved differently. This lens is just glass, no special features are packed into this lens (like image stabilization or an internal IF motor). At 450 bucks, their is no excuse for this poor quality. I might have paid only 300 bucks and still not be satisfied with this lens, especially after going through such a long drawn out process of having to test 3 lenses, and ship 3 lenses, and type this review with no 28-75 lens to be found in my house for they are returned or sitting in the repair shop!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!Tamron has no quality consistency at all, and I would advise anyone who has a Tamron lens to double check their pics by doing infinity focus tests..basically, take a picture of a tree sitting by itself in the yeard 25 feet out, aiming the camera in a 45 degree downward angle and at the trunk right where the trunk meets the ground and another shot at the tree straight on. Then observe grass in the photos. This is the best way to do a "real world" test, not a flat chart test, to see if the lens is acting appropriately. Keep in mind, portraits, pet photography, and action photography are not going to show corner softness or de-centered sharpness for the very center of the picture (human face, the pet's face, etc) is the only thing in the plane of focus. Architectural and landscape photography are what demands corner to corner sharpness and I have a hunch people are not using this lens for such, thus so many good ratings. I do see this lens as being a good portrait lens and that seems to be the primary (only) use for this lens by so many using it that are ALSO into extreme photography. This lens just does not yield good results in any other condition.Also, as quoted from Photozone.de regarding test results of the Tamron 28-75 (a professional photography equipment test website): '...it should be mentioned that this is the 2nd tested sample of this lens and both showed centering defects - this is worrisome. The build quality of the lens is decent but nothing to rave about. If you can live with the rather odd zoom range within the APS-C scope the lens is worth a deeper look - assuming you can get a good sample.'Other websites had the same findings concerning quality control. On a positive note, they all had the same findings when it came to a good copy of the 28-75 lens - tac sharp results at f4 stops through the entire focal range, if not at f4 stops, then at f5-f5.6 stops. Overall, you have to roll the dice, or be patient and send your new lens in for repair or replacement once you get it. This is NOT how to run a business, but it seems to be the market standard for photography equipment. Canon and Nikon (and sometimes Pentax) users all have the same complaint. PATHETIC!OTHER POOR QUALITIES-BASED ON ALL 3 LENSES USED-----------------------------------------------1- This lens colors photos with about +15% amber. I have to tweak my white balance on my Pentax K-R to get the proper color (with a Pentax K-R, +4Blue, +1 Green). I actually used a 4th Tamron 28-75 on a Canon T2i, the results for poor color were worse, on top of this, the T2i did not have but one customizable white balance setting where the K-R can be changed on every preset (just one reason I chose the K-R over the T2i, though the T2i is a good camera - I am not reviewing cameras here and do not want to disrespect Canon or Canon users).2- Poor manual focus ring - it has extremely short travel making it very touchy to manually adjust focus - barely touching it quickly puts you out of focus again3- Often miss focuses4- Not a 2.8 lens. Count on f4 stops maybe, if not, 5.6. However, 2.8 stops can be used to add nice soft focus effects, so it has its advantages - but this is not per specs and not using the lens as intended.5- Lens glass is very sticky and attracts particles. My Pentax lenses are smooth thus clean easily and do not attract dust like this TamronNOTE:As entry level as my Pentax K-R kit 18-55 DA L lens is, it performs nearly as well as this Tamron lens in some, not all, settings. Since having problems with the Tamron, I acquired a Pentax 18-55 AL II which improves on the sharpness of the 18-55 kit lens and the color and contrast is much better. To this point, the AL II has proven better than the Tamron and has a more useful zoom range allowing more wide angle shots while also allowing for better focusing, a quick shift focus ring so using the AF/MF button is not necessary, and the focus ring has longer travel that is far smoother and more accurate than the Tamron 28-75. Additionally, my Pentax 55-300mm, while not RATED as sharp as the 28-75, easily outperforms the Tamron as far as consistent sharpness and focus accuracy, and from 70 to 270mm little difference in sharpness can be made compared to the Tamron at its best settings. The Tamron 28-75mm is RATED sharper at any given stop, but I can almost not see a difference. Honestly, I would rather have a consistent performer than have a lens I cannot use at all from 28-45mm when advertised to be 28-75mm unless I want to intentionally blur pix all the time!!! I did not buy a 45mm-75mm lens, I bought a 28-75mm lens and expect it to work as such. Not a big expectation for 450 bucks!!!I gotta say, buying a camera lens is the hardest thing I have had to do in my 3 decades of shopping - quality control and poor performance really plagues this market. It is not limited to Tamron, though I am extremely disappointed with them. All I can say is I hope you have better experiences than so many of us who have not!!!***UPDATE 12-20-2011***Concerning my 3rd Tamron lens for Pentax which I chose to keep, as you recall in my review above, I had a lower left quadrant blur in pix taken at 28-45mm focal lengths. I sent my lens in for repair on the 32nd day of ownership the first week of November in which I was told policy is that first time for repair customers must pay shipping - so I did. I was told there was a 5 day turn around, and I did receive the lens back timely, but WITHOUT REPAIR. I called Tamron immediately and resent photos showing the blur. Rep 1 dodged my calls and emails for a week. I called again, getting Rep 1 again, I refused to speak to him since he has been dodging me, and asked for another Rep which I then proceeded to deal with. I sent pix to this Rep, Rep 2, and he did immediately confirm there is something wrong with the lens based on the pics I sent in. I was sent a shipping label and told to return the lens, and told they will definitely be able to repair it this time and that there is a 5 day turn around. So, I shipped the lens on December 8. On December 14, I receive an email that they got the lens, but UPS confirmed its delivery on December 12. Okay, I will deal with the lag, maybe Tamron is busy. So, another week goes by, the lens has been there for 7 business days, I call and nobody from Customer Service at Tamron has contacted me to this point and nobody knows the status of my lens, just that they have received it. I then demand a call back from a manager. So, rapidly, a manager did contact me...now the bomb....the Lens as of December 15 has been sent to JAPAN!!! I was informed I will not see it for more than 2 weeks - now I don't have my lens I bought 2 months ago for Christmas. The only reason why I kept this lens was due to the fact that within the Amazon returns window of 30 days, the first 30 days I had the lens, I contacted Tamron to tell them I had a 3rd defective lens and they said they can just calibrate the lens if I chose to keep it. Keep in mind, the only reason I went this route was because I already purchased 2 outright faulty lenses and so many people have said this is a great lens so I wanted to give Tamron a chance. WOW, what a HUGE mistake. I was never told I would have to pay for shipping for calibration of a new lens which should be working to begin with - I guess I should never have assumed otherwise. Also, I was told prior to deciding to keep the lens that the repair facility is in New York (NOT Japan) and turn around times are 5 days. Another LIE.I explained my situation kindly to the manager I spoke with and requested I at least get a refund for the shipping costs of $15 for the first time I had to send the lens in. This manager upheld all remarks I have heard back from Customer Service Reps to this point, "we at Tamron do not pay for your initial shipping to have a lens repaired - the customer has to pay the first time" Okay, so, the lens is brand new, it should not have been faulty to begin with, but it is the customer's responsibility??? WOW. And now they see they are at fault, but will not refund $15. SO, I demanded a full refund of the lens for it is brand new, it is out of the country for which they have chosen to do after lying to me the repair facility is in New York, they possess all the paper work, the box, the lens and it is out of my hands - I told them I don't want it back. I was told they do occasionally refund entirely in this situation. WOW AGAIN. They would rather refund me $460.00 for this lens than just $15 for my initial shipping to have this lens fixed that should have been functioning to begin with. You think they would give a 10 percent discount on future purchases, refund a portion of the amount paid for this lens, offer a new lens, do SOMETHING to promote their product and take care of the customer while making them feel good about a product that was purchased from them....NOT so...they just take the lens away from you and propose to give a refund. Amazing, to say the least.I kept this lens past the 30 day return window at Amazon in good faith that this is a good lens according to reviewers. I kept this lens in good faith that Tamron would stand behind their recommendations that I should keep the lens and that they could just calibrate it to fix it to the condition the lens should have been in to begin with, and within 5 days. You think they would promote their product by returning it to new condition within a reasonable time frame and fix it at the location they said their repair facility exists. You think maybe they would replace the defective lens with a new one. NOPE! Wait for MONTHS, get a run around, or just don't use Tamron products...***UPDATE 2/6/2012***Tamron did in fact conclude the lens was not reparable and refunded me in full for the amount I paid for the lens from Amazon. As difficult as this has all been, it is very credible to them since they backed up their warranty/quality guarantee. This does make me feel more trusting towards them for possible future considerations of their products, though at this point, I will still not buy from them. Shockingly, it has been 5 months to the day since my fiasco with the 28-75 lenses began!!!