Lots of news came out of the recent 2010 Photokina convention in Cologne, Germany. Unfortunately, there were few really exciting announcements of new products.  Sure, the various vendors had this or that they were parading but for the average photographer enthusiasts or professional the news was fairly pedestrian. Nikon trumpeted their new lenses (including the very intriguing 24-120mm F/4 VR), Canon bellowed about their new 60D which is very ho-hum when you consider where it sits price wise between the T2i and the 7D (all three models share the same 18 megapixel sensor). The only really interesting news was the announcement of the new Sigma SD1 dSLR which features a 15 megapixel Foveon sensor. Unfortunately the details around the SD1 were sketchy at best and it could be some time before we hear more about this intriguing offering.

No, what people were really interested in hearing about was the next flagship model from Canon. Where is the 1Ds MKIV??? Its getting time for a replacement isn’t it? Well, yes, it is. According to the past history of model development from Canon, the 1DS MKIV is getting very close to due for announcement. Rumors have spread all over the web for years on the rumored specs and release dates but all that really has been put to flight by the persistent silence from Canon. However there is still the slim possibility that Canon makes an announcement in October of 2010. After all, last year in October they announced their new 1D MKIV (using the APS-H sensor). It could still happen this year. However, if Canon doesn’t announce a new 1Ds MKIV by early November then it will most likely be late 1st quarter of 2011 before the new flagship model is announced.

Canon isn’t the only manufacturer whose flagship model is looking a little long in the tooth.  Sony’s own A900 is well overdue for an overall and the rumor mill there has been silent. Even Nikon who announced a D3s model in October of 2009 is long overdue for a new flagship to replace its D3x and/or D3 (limited by its comparatively low 12 megapixel resolution).

Let’s hope that October brings big news from all three of the major DSLR manufacturers.

Photopurity has taken some time to review the 24-70mm F/2.8 EX DG Macro lens from Sigma. When it comes to non-OEM lenses you’ll find that many photographers downplay the performance of Sigma and Tamron the two largest third party optic vendors.  Several will claim that their lenses are too soft or that their AF is slow, unreliable or noisy. I’ve handled dozens of optics from both Sigma and Tamron (as well as Tokina and a few others) and my general conclusion is that this reputation is born of either ignorance or perhaps a snide sense of lens snobbery. Sigma has for quite some time now produced excellent optics that are competitive with Canon’s own and some push the limit even for Canon’s special line of L series optics. Quite an achievement for a company that has to reverse engineer their optics. Let’s take a closer look at the Sigma 24-70mm F/2.8 EX DG Macro.

Build and Ergonomics

The Sigma 24-70mm is marked as an EX lens which means it belongs to Sigma’s line of high quality, high performances lenses. This also means its built with Sigma’s premier construction and finish. What this means practically to most consumers is that you may or may not like the particular durable finish of the lens. Although I personally like the gritty finish I’ve heard many others say they’re not particularly fond of it. At any rate, the lens is solid, very durable and would stand up to day to day abuse better than most consumer lenses made out of cheaper plastic. Like any lens (including my Canon 70-200mm F/2.8 IS USM L Series) I would not want to drop it from any distance or bang it against a concrete wall.

Ergonomically speaking I do have some quibbles against the Sigma for featuring an extremely small (comparatively) zoom ring while boasting a massive manual focus ring. I can count on one hand how often I use manual focus nowadays and I would have much rather flip flopped the two. The zoom ring can be hard to find at first even to an experienced DSLR user.

The Sigma 24-70mm features an inverse zooming dynamic and by that I mean the lens is at its largest (longest) when the focal length is set to 24mm, its most compact when zoomed to 70mm. This can seem counter intuitive but its hardly the only lens with similar functionality.

Autofocus

I can say this about Sigma, even before they introduced their HSM technology, they’ve always had fast AF. The Sigma 24-70mm EX DG Macro is no exception. The Sigma features an extremely fast focusing mechanism although I do believe it to be just a tad slower than HSM or Canon’s USM. After spending several hours with this lens in multiple locations shooting everything from Macro to landscapes in varying lighting I can say that the AF accuracy is splendid in the Sigma 24-70. My only quibble and it is a small one is that the focusing can be a bit noisy compared to slightly more modern optics with HSM or USM. Beyond that, you’ll find it light years faster than say, Tamron’s slower AF.  When using this lens on my Canon 5D II I found it to be accurate when using just about every type of focusing (AI Servo, AI focus, Single point etc).

The Sigma 24-70mm bears the designation of Macro from Sigma and indeed it is a close focusing lens. You can get to approximately (I didn’t measure exactly) 3-4 inches from your subject and the lens will still focus. Although I wouldn’t recommend this lens particularly for its close focusing it is a very nice option to have and once you’ve gotten used to its flexibility switching to another lens can be a rude experience.

Weight and Size

The Sigma 24-70mm is a fairly large zoom, which is to be expected as it features a very fast F/2.8 aperture throughout its zoom range. The lens is by no means a lightweight, having considerable heft but then again most consumers are expecting this when purchasing a F/2.8 zoom.  At 24.7oz the lens is weighty but then again weighs about half what the Canon 70-200mm L F/2.8 lens weighs. I believe if you are in reasonable shape and have a decent strap you should have no problem toting this lens around all day, I certainly didn’t.  The Sigma utilizes an 82mm filter so that alone should give you a little bit of an idea how big this lens is. 82 is not all that common of a filter size and the only one that comes immediately to mind is the Tamron 28-105 F/2.8 lens.  If you’re looking to purchase a filter in this size be prepared to pay a little extra due to the size being less common.

When the Sigma is in its compact form it measures about 3.5 x 4.5 inches (88.6mm x 115.5mm) but when extended (at 24mm focal length) it grows to about 6 inches in length (152mm). Considerable but not backbreaking or even all that attention grabbing which is good in most cases.

Cost

At first I thought the Sigma 24-70mm EX DG Macro was discontinued but a quick visit to Sigma’s website shows the lens still in their current lineup.  However the suggested MSRP of $750.00 is not exactly in line with actual street prices. You can typically find this lens used but in good to excellent condition for around $375-450. I actually found mine for a little less.  Brand new you can buy this lens from Amazon for $569.00. (Buy yours today)

This is where I judge a lens most. Who cares if it feels like it was forged by an immortal in your hands if the image quality doesn’t measure up? If a lens delivered impressive, clear, sharp, beautiful images then I wouldn’t care if the designer covered it in thorns. (Ok, I would probably care a little but you get my drift).  The Sigma 24-70mm gave me beautiful images throughout the zoom range, from 24mm all the way out to 70mm. What I was most interested in, of course, was the images it produced at F/2.8. After all, that’s why you buy a lens to use it at its maximum aperture. If I only needed F/5.6 then I would have saved some money and bought a cheaper lens. The Sigma delivered, even at F/2.8. I found I had sharp, clear images with excellent detail and colors. The Sigma passed with flying colors. I found it to be an excellent performer in every aspect. Image quality does improve slightly if you stop down to F/4.0 but even at F/2.8 you’ll find your images are excellent. I used the Sigma on my Full Frame Canon 5D II and it performed acceptably throughout the entire focal range, performance on a crop sensor camera (ala Canon 40D) would probably be even better.

So, all in all, if you’re looking for the performance of the much touted Canon 24-70mm L F/2.8 but don’t have or don’t want to spend the $1000-1,500 that it commands then this is a wonderful little substitute. It can deliver the image quality for much less. The only minor quibbles I have is that its AF is a little noisy (small distraction) and perhaps just a hair slower than HSM/USM but not much. I heartily recommend it to anyone looking for a quality lens.

This is a restored article from early 2010.

Photopurity has spent about three months using a Tamron 28-105mm F/2.8 zoom in connection with both a Full Frame Canon 5D II and an APS-C crop sensor in the 550D (Rebel t2i). After using this lens for a variety of purposes including one wedding and one convention event, we thought we would finally get around to performing a full review of its performance.

First things first, this lens has been discontinued by Tamron and is no longer manufactured. It was produced in all the major mounts during its active phase and used copies of this lens in all mounts are in the neighborhood of $300-400 depending on condition.

Size and Weight

With any fast zoom, the lens is going to be big and heavier than any of its slower peers. The longer the zoom range and faster the maximum aperture will greatly increase the dimensions and weight of the lens. The Tamron 28-105 F/2.8 is no exception. The lens has considerable heft coming in at 31.4 oz (880 grams). That’s about 17 ounces lighter than the considerable Canon 70-200mm F/2.8 IS USM L lens and about 23 ounces heavier than Tamron’s current 28-80mm F/3.5-4.5 Aspherical lens. The physical dimensions are 3.4? x 4.4?.

Construction and Ergonomics

The Tamron 28-105 f/2.8 is fairly well constructed but makes considerable use of plastic. The zoom ring in particular has a cheap plastic feel with few ridges for easy gripping. Compared to more modern zooms the 28-105 F/2.8 shows its age. The lens features a standard AF/MF switch.  The manual focus ring is very thin and can be difficult to find just by feel.  The zoom ring itself is also quite stiff and can require more than expected force to twist. After using the lens for three months extensively and considering the lens itself was already used previously we did not find the action to smooth any, it was just as stiff at the end of 3 months as there was at the beginning.

Image Quality

The main reason to buy a fast zoom (F/2.8) is to precisely to use it at that maximum aperture. The Tamron 28-105 performed extremely well throughout the range although at 105mm it did noticeably soften. Sharpness was pretty consistent throughout the rest of the range. Its an excellent portrait lens with a considerable focal range which works very well on a full frame body like the Canon 5D II.  Even on a crop sensor body it can give a very nice range presuming you don’t need the very wide end (28-105 x 1.6 crop becomes: 44mm – 168mm).

One thing that became very noticeable with the 28-105 F/2.8 is the color saturation is very strong with this lens. I had never noticed just a strong effect of a lens before in any of my reviews. Images produced using the Tamron 28-105 has a deep rich saturation of hues so much so that I had to back off the saturation settings in my camera body to counteract the effects. Switching between my Canon 70-200 L produced noticeably different images in terms of image saturation. This can present a problem when you need consistent color tone. Shooting RAW would mitigate this problem.

The Bokeh of the Tamron 28-105 F/2.8 is not entirely pleasing. It can take a harsher look that is reminiscent of “blades of grass”. Better of course than a slower standard zoom but not nearly as lush as a prime or even the Canon 70-200 F/2.8 L or even the excellent Sigma 24-70mm EX DG Macro.

Price

Since the Tamron 28-105 F/2.8 is no longer in current production by Tamron, you will have to find your model on the open market. Used models are routinely carried by Adorama, BHphotovideo.com and KEH.com. Depending on the condition of the lens and whether it comes with a hood and accessories the price range should vary between $300-400.

Autofocus

Tamron has never been considered a leader in autofocusing technology in their lenses and the Tamron 28-105 f/2.8 is no exception. I found it to be slow but generally accurate. In low lighting it took some time to acquire focal lock but when it did, it generally was correct. Interestingly enough, it seemed a touch faster when combined with my 550D (Rebel t2i) than on my Canon 5D II.

Conclusion

I was pleasantly surprised with the Tamron 28-105 F/2.8. After testing Tamron’s also out of production 35-105 F/2.8 only to find it disappointingly soft throughout the entire focal range I assumed I would discover the same with the 28-105. I couldn’t have been more wrong. The Tamron 28-105 produced consistently sharp images even (and most especially) at its maximum aperture. I would not have been satisfied with a lens that needed to be stopped down to F/4.0 in order to get good results so its performance at F/2.8 was essential.  For the price, the lens performed admirably and the only real quibble I had against it was the extreme color saturation it produced. That’s not necessarily a major problem unless you are switching lenses often and need to compensate for the differences between them. For use with a full frame camera you won’t find another lens out there with a comparable focal length. If you don’t need the 70-105mm range then I would recommend the Sigma 24-70mm EX DG Macro as a similar priced competitor that performs just a small bit better than the Tamron. However, since I found that I needed that extra length, I was very satisfied with the Tamron 28-105 F/2.8.