I really like shooting portraits with my Pen 70mm f2.0. It's pretty sharp for a forty year old lens....

Ben.  Olympus 70mm f2.0 Wide Open.  Panasonic GH2

Like most fans of micro four thirds cameras I've heard about the eminent arrival of the Olympus 75mm 1.8 lens for months now. By all rights it should be a great lens.  It's a fairly long focal length (which is generally easier to design) and given the proven prowess of Olympus's lens designers it should be sharp and contrasty even wide open.  

With this in mind I went over to the Olympus Pen drawer in the Visual Science Lab Armory and extracted what I think is the progenitor of the new lens, the 70mm f2.0 Zuiko from the late 1960's.  Yes, they actually knew how to make lenses out of metal and glass even back then....

I had always remembered this lens as a good performer but I wanted to revisit it given the much improved cameras I have at my disposal these days.  So I pulled out the GH2 (which seems to perform as well as the OMD, as long as we stay away from the "nose-bleed" ISOs....) and I put the 70mm f2.0 Zuiko on with the help of a Fotodiox adapter and I called Ben into the studio.

Ever the perfect child he dropped his chemistry homework on to the top of his desk and hustled to the studio.  It would have been easy to set up conditions that would favor even the worst lens, if that had been my intention.  I could have lit Ben with hard flash for the appearance of high sharpness.  I could have stopped the lens down to its "sweet spot" which makes every lens look like a contender....

But I chose to shoot a quick portrait at ISO 160 with the camera on a tripod.  No IS in this combination.  Just straight ahead, late 1960's technique.  I shot the lens wide open and put it on a Berlebach wooden tripod.  The shutter speed was 1/20th of a second.  The depth of field was so small that just by breathing Ben would move in and out of fine focus.

So, what did I find?  I have the benefit of having looked at the file at 100%.  Where I focused (Ben's eyelashes) the sharpness is easily equal to any of the camera and lens combinations I've shot over the years.  The tonality is wonderful. The contrast right out of camera is lower than that of a modern camera/lens combination but it sparkles up well with a small application of curves in PhotoShop.

By the time you reach the kid's ears or the back of his tee shirt collar the lens is already going out of focus quickly (hello all you crazy people who think limited depth of field is only provence of larger sensor cameras).  By the time we hit the background all focus is totally gone.  And the background is only six feet behind him.

I probably won't be buying the new lens.  I have one near that speed and focal length that is already very, very good.  But I'm excited for everyone who does buy the new lens because I think it will be another product in a line of game changing products being released by Olympus this year.  It will either push Canon and Nikon back to the design computer to make better and more exciting glass or it will push hundreds of thousands of camera users away from last century paradigms and into using the new technology that's even now changing all the maps of photography.

The "reverse roadmap" that will allow you to understand what Olympus is doing is the original Pen system.  You have only to study it to parse what's coming next.  A whole line of fast, sharp-wide-open lenses and a wide open playing field.  

The defensive among us harped on the OMD's focusing as a reason why we "won't see any micro four thirds cameras at the Olympics..."  One or two more lens releases and we'll be able to say "bullshit" to another worn out assumption by the mirrored class.  EVF, Mirrorless and small sensor cameras are here to stay.  No....that's not quite right.  They are here to dominate.

The next camera from Olympus will doubtless offer hybrid autofocus for fast, continuous performance.  Couple that with a bag of fast long optics that weighs less than one big, fat, L lens and photographers would be crazy to choose the "old school" methods with their attendant bad backs and hernias.  You heard it here first.

And it all started with the original Pen half frame cameras....

Going backward to make better photographs. The slow movement.

Slow ISO's mean more latitude for opening up shadows without noise.

In the race for speed and glory we may have forgotten an overriding consideration in photography.  The ultimate image quality.  The pursuit of high ISO performance seems to have clouded the judgement of both manufacturers and practitioners as to what the end clients of commercial photographers really want, and have always wanted: good, clean, sharp images of the product, service or people being presented in the advertising and promotion.  Getting an "acceptable" image at 1600 ISO is not the same thing as getting a "perfect" image using ISO 100.  Or ISO 50.

Every camera seems to have a base ISO at which the sensor is able to achieve both the lowest noise floor and the highest dynamic range.  In fact, the two parameters go hand in hand.  As the noise floor rises the dynamic range declines.  The race to get to higher and higher ISO's has led camera makers to do strange things.  Many sensors (such as the one in the Olympus OM-D and EP-3) now seem to be optimized to deliver their best performance at ISO 200.  It's ultimately counter-intuitive as most of the lenses designed for the smaller sensor format seem to be near diffraction limited at nearly their maximum apertures.  When used outdoors or in any favorable light (which is the predominant environment for the vast majority of picture taking) these cameras struggle with too much light.  When shooting with an optical system like the Leica Summilux 25mm 1.4 I find that I struggle to use it at its real business end (aperture-wise) because I am limited by the highest shutter speeds of many cameras.  Pity, since the lens really performs well around f2.  And it has a wonderful aesthetic look at f2....

One maker who seemed to understand that low ISO's aided in getting quality images was, ironically, Kodak.  They had a wonderful mechanism in their SLR/n camera with which you could set the camera to ISO settings of 12, 25, and 50 and the camera would do long exposures which were really a series of exposures stacked on one another with all noise anomalies cancelled out.  The end result was files that could be printed to enormous sizes with high sharpness (partially lens dependent) and with absolutely no electronic or sensor noise.  While the cameras had to be used on tripods and the exposures could run into the seconds the process was as easy as shooting with a view camera and that was something many pros did right up until their ultimate conversion to high res digital capture.

When I switched camera systems to the Sony SLT cameras I tested them at various settings.  At first I was a bit disturbed by the high amount of noise present at ISO 3200 and beyond.  I chalked it up to the price I had to pay to get 24 megapixels on an APS-C sensor. What I have now come to understand is that the engineers at Sony were/are working with a sensor, the performance of which peaks at ISO 50. Rather than being a design fault it is, in fact, a chance for us to go back to the practice of wringing ultimate quality out of our files instead of ambling down the path of least resistance and handholding our cameras at ISO 12,000 and wondering why the saturation and integrity of our files is....mediocre.

People say that the Sony sensor is really optimized at ISO 100 but they don't have any more objective information at their fingertips than me.  I tested the camera at all the lower settings, up to 200, and I looked at them at 100%.  I also looked at the DXO DR curve that showed 50 ISO as the highest differential between noise floor and signal.  Doesn't matter if I'm 100% correct or if Sony has massaged the ISO 50 setting in a way that's similar to the way Canon and Nikon massage their high ISO's with software processing.  All that matters are the resulting images.

I spent a large part of my professional career shooting black and white films like Agfapan APX 25 (ISO 25) and Ilford Pan-X (ISO 50) as well as color films like Kodachrome 25 and 64, Ektachrome 64 and 100 and various slow Fuji films because, when blown up big, they showed more detail, more sharpness and less grain than their faster brothers.

With the new Sony cameras I've started to hew back to the old ways. I'm finding that using a tripod and medium apertures will get you a very high impression of image sharpness.  The Sony a77 also incorporates a unique setting called Multiple Frame Noise Reduction.  The camera shoots six frames in a row at whatever ISO you want then micro-aligns each frame, kicks out all spurious and random noise, blends the files together and presents you with a noiseless image.  

In studio portrait situations I'm pulling out bigger strobes or using longer exposures with continuous lighting.  It's a different look.

I know there are times when a high ISO is useful.  If you are shooting fast action in the low lights of the UT Swim Center you'll need to start at 1600 and go up to freeze fast action.  To freeze a dive might require you to go into the 6400 ISO area.  When you go to the summer Olympic this year you might need fast ISO for the indoor venues.  And if you shoot NFL Football for a living you certainly don't need to confer with me about which lenses and what ISOs you'll need to use in some God foresaken taxpayer funded arena somewhere in the midwest.  But I'm guessing it will be fast, long lenses and a high ISOs.  

I use high ISO settings on cameras when I shoot theatrical dress rehearsals.  But I don't need high ISO in the street, on the beach, in the mountains, at the outdoor pool or, with fast lenses, in most of the restaurants and coffee shops I patronize.

But lately I've seen just how different ultimate low ISO performance can look.  We moved away from top quality as a compromise between camera handling and convenience.  But it is a different look.  Perfection is a different look as well. (not that we'll ever achieve it...).

I'm starting a movement.  It may end up having only one full time member (me) but it's antithetical to the pervasive practice of photography today.  I'm going to try to shoot every possible digital photograph at the optimum ISO of my cameras.  In the case of the Sony a77's I've decided that the right number is 50.  In a pinch I'll go to 64 or 80 or even 100.  I'll practice my steadiest camera hold and try to optimize all the other parameters.  That means shooting at f4 and f5.6 with most of my lenses.  It means shooting the Leica lens on the m4:3rd cameras at f2 and f2.8.

I already try to shoot as much as I can on a tripod and I keep one in my car.  I won't use it for street shooting because I'm more interested in being highly mobile than perfect but in genres where rapid response is secondary to vision I'll continue to press a good tripod into service.

For generations we worked easily with slower films and made images that stand the test of time (perhaps better than digital).  There's no reason why we can't migrate these best practices back into our digital efforts.  The end result might just be much better imaging.  A slower and more thoughtful pace.  Fewer reasons to join the seasonal hunt for the newest and greatest cameras.

And most importantly, prints and electronic images that you can be proud of.  Not proud because you were able to pull something out of a bad situation with a compromise...but actually proud because you came closer to achieving the potential of your vision.

So, for me it's about good tripods and good glass.  It's about letting subjects take time to settle.  It's about finding and using optimum apertures and shutter speeds.  Amazingly, there is a reason why the camera makers put all those different ISO settings on every camera they sell.  While most people will race to the high ISO extreme the engineers know that most things look better at the other end of the "dial."   Slow down and shoot better.

Finally, in marketing and advertising and art, if everyone is rushing to do things one way it's always more interesting to take the opposite point of view from the pack.  Herds don't make art. 

Just finished breakfast and I'm already thinking about lunch. And the Sony 30mm Macro Lens.

Avocado/Ceviche

Vegetarian Picadillo

 Plating the puerco. 

I recently posted a blog about shooting food for a new Austin restaurant called, El Naranjo.  I came across these images today as I was virtually tidying up and I took a closer look at the lens with which I photographed them, the Sony 30mm Macro (DT).  It only covers the APS-C format but that really doesn't concern me at the moment since all my Sony cameras are smaller sensor cameras.  I'll re-think my lens inventory if I decide to buy the once rumored, now confirmed, full frame Sony when it comes out. (I spoke directly with a Sony representative over the weekend and he absolutely confirmed that the full frame body was coming. I inferred from the finer points of our conversation that Sony is testing two versions, at the moment.  One is based on a 36 megapixel sensor, ala Nikon, while the other is based on a much enhanced 24 megapixel sensor.  Sony seems to be trying to gauge where the greater demand is:  Ultimate noise performance or ultimate resolution.  I hope they come down on the noise performance side, not because I need a much quieter camera but because I like the workflow reality of smaller raw files...).

The Sony 30mm Macro has two things going for it:  Price ($199) and "on sensor" performance.  But it has two things going against it: A loud and grabby autofocus motor and a cheap overall finish.  I like using the lens in manual focus mode, with focus peaking, so that just leaves the aesthetic deficiencies to grapple with.   Grappling complete.  I like the lens enough to overlook the last century plastic finish.  In fact, it may become a new fashion statement of downsizing.  1970's Russian industrial chic.

So, back to the important issues: Where have I decided to go for lunch?  My friend, Mike, and I are headed to Maria's taco express on S. Lamar.  The picadillo tacos are always good and I can get one enchilada verdes on the side.  Sold.  Hope your monday is hopping.

There's no law that says you can't own more than one really cool camera.

Last weekend things got a bit rocky on the blog when I suggested that the Olympus OMD camera represented a tipping point in the evolution of cameras aimed at advanced amateurs and working pros.  The cadre of very stupid people immediately started screaming incredibly silly stuff along the lines that we'd never see a micro four thirds camera at the Olympics (as though the people who photograph sports at the Olympics are a great and representative cross section of all working photographers and share the photographic interests of the vast 99% of non-professional camera buyers....). I think they meant to say something about full frame cameras having significant imaging advantages over the smaller sensor size of the m4:3 cameras.  They were unable to make the sentences and thoughts match up.

Another less vituperative crew wanted to hold forth about focusing speed in AF-C crippling any use of the m4:3 cameras but I'm pretty sure, given Nikon's great work in incorporating phase detection (fast) autofocus on the their sensor, that all the camera makers will master the vagaries of fast focus within a generation or two.

But the most obtuse group were a contingent of rabid Panasonic owners who felt that giving credit to the OMD was totally misplaced.  That all credit for ground breaking should go to the Panasonic GH2 camera and several other models of Panasonic cameras.  I think they missed the point entirely but that didn't stop them from questioning the number of brain cells I have left, my parentage, and even the veracity of my Kenyan birth certificate...

One gentleman in particular felt that I'd "jumped the shark" and "gone off the rails" in ignoring the Protean contributions of the Panasonic machines.  (Here's the article)

My point was not that good photographers and smart people would finally accept the smaller, mirrorless format (we had already done that several years ago...) but that now the mental blocks that constrained the mainstream of photographers had been removed by a combination of features, performance and handling, resident in perfect measures, in the Olympus OMD.  The Panasonics clicked a lot of boxes.  The Olympus pretty much clicked all the boxes.

But my intention was only to point out that the whole category is now pretty much ready for prime time.  And I come now not to bury the Panasonic line but to praise it.  Because I've owned several Panasonic m4:3 cameras for quite a while now and like them very much.

In fact, today I went to see art downtown and I took along one of my favorite street and gallery shooting cameras, the woefully underestimated Panasonic GH2.  I coupled it with one of my favorite mini-format lenses, the Leica Summilux 25mm 1.4.  I could have reached into the drawer and pulled out a Hasselblad or a Nikon F or a Kodak full frame digital camera or a Sony camera or an Olympus m4:3 camera but I chose the GH2 for its stealth, its smooth working relationship with the Pan/Leica lens and its convenient size and weight.

In my mind the IQ stumbling block resides mostly these days with the IQs of the users and not the cameras.  I'm sure that the Olympus is somewhat better at very high ISOs and at image stabilization.  Neither of which I needed walking down the sunny streets of America's current most popular destination to relocate...  The trick with smaller sensor cameras and super high res cameras is to work as close to wide open as possible in order to minimize a phenomenon known as diffraction.  The further you stop down, after a certain point, the fuzzier your image gets.  Wow.  Science.  Light rays bending around the edge of a lens diaphragm.  Who would have thought?  Oh, yeah.  Real photographers figured that out back in the film days...

So higher ISO would have been counter productive.  And, already working at 1/1,000th of a second I didn't feel the need for lots of IS either.

The cold, hard reality is that all the cameras on the market today are pretty darn good.  Especially when you consider that a huge, huge percentage of the images output are viewed at no larger than 1200 pixels wide on the web, and that fewer than 30% of all images generated by advertising and commercial photographers will run in printed applications.  Wow.  So Olympus was pretty much right on the money---for most users---when they said that 12 megapixels was the sweet spot for resolution.

People talk a lot about stuff but I'm not always sure they have any knowledge about the stuff they say.  Take the bad Panasonic Jpeg Color which I've heard about for years now.  Can you say user error? All the Jpeg parameters (sharpness, contrast and saturation) are controllable in the camera.  You can literally set the GH2 files to look the way you want them to.  Is it the camera's fault if you are too incompetent to read the manual and then change the settings to your liking?

My readers tell me they love to read stuff that's more about the nuts and bolts of an interesting job or the thoughts behind a style or a technique and that they really aren't here for the equipment reviews.  That's a good thing because, based on the feedback I've been getting when writing about Olympus gear, I don't know much about equipment anyway.  But the reality is that when I write about Olympus gear my readership surges to over 50,000 pageviews in a day.  When I write about non-gear it drops by half.  After reading many of the responses I got from the latest flurry of gear reviews I think I might be happier sticking with my regular readers.

In closing I must say that the Olympus OMD is a very nice camera.  We might just be able to buy one as the next model is about to hit the market, given demand.  In the meantime the Panasonic GH2 (while not really a "break through" camera) is a really fun camera to shoot and puts out files that I think stand up quite well in real, every day shooting, to just about anything on the market in their price range....or even a bit above.

I am not an Olympus or Sony fanboy.  I am a camera fanboy.  Well, older fan-gentleman..

Kirk's Books on Amazon. Please buy one.

We're just on the kind edge of Summer. Swimming is always on my mind.

I started swimming competitively in elementary school.  In high school while most other kids were drinking beer and getting high and driving around thinking about getting into trouble I was hitting the pool, along with 35 or 40 other driven, insane teens at 5:30 am, five mornings a week.  Every week.  Including holidays. We'd get in two hours before school started and then head back to the pool after the last bell rang for another hour and a half. On  weekends we didn't have "official" practice but we'd head to the pool in our own little groups and leisurely knock out four or five thousand more yards. I remember having bad swimming withdrawal one day and my parents telling me, "Tough. The pool is closed on Christmas day."

When I got to college I was a walk on to the team.  We did just what we did in high school.  We got up early and swam.  And then we cracked the books and studied.  So is it any wonder that now, 36 years later, I try to start every day with a swim?

I belong to the Western Hills Athletic Club Masters Team.  Our pool is 1.2 miles from my house.  We have practices at 7 am, 8:30 am and noon on Tues-Fri. and 8:30 am til 10:00 am on Saturdays and Sundays.  I've learned to cope with the pool being closed on Mondays by heading down to the famous Lady Bird Johnson Hike and Bike trail that encircles the Colorado River in the middle of Austin and running four or five miles instead.

When we swim there are often two or three world record holders in the pool, at our workouts.  Some days we have several Olympic gold medalists in the mix.  Lanes five and six (the fast lanes) are sometimes clogged with some All American swimmers who have just recently graduated from the University of Texas at Austin.  They go really fast. Austin is a big competitive swimming magnet.

On a good morning I'll go 3,000 or even 3,200 yards.  I try to catch the 8:30 am workout because I hate waking up too early. I've done enough of that.  Lately though, I've been getting Ben up for cross country and driving him to practice so I'm hitting more of the early workouts.

Unlike photography there's not a lot of gear to obsess over.  The pool is maintained by professional staff.  The workouts are planned and supervised by experienced coaches.  We each have our favorite pair of goggles (under $20) and maybe a back-up pair.  We use pull buoys and paddles for pulling sets but those are also cheap, last forever and never seem to get obsolete.

We have a set of training fins for sprint kick sets and those do wear out over time.  I generally plan on getting a new set about once a year ($35).  We've each probably got two or three practice swim suits in our gear bags, in various states of decomposition, but we're careful not to let them dissolve on us.

We have a mix of swimmers.  Some come to us to train for triathlons and some come to us after they've crippled themselves by running too many marathons back to back.  But most are high school and college athletes who've never given up, never slowed down and never lost the taste for the endorphins and adrenaline.

The one thing we all share, whether we joke around or are totally serious, is the discipline to get in and do the work. Rain or shine (but not during lightning storms..)  And the discipline that we've developed in the pool translates into nearly everything else we do.

In truth, I've never defined myself as a photographer.  When I think of who I am the first thing that comes to mind is = swimmer.

So what does this particular blog have to do with photography? Not much. Except to point out the need to have different interests.  I swim because I love the feeling of being in shape.  And I love the camaraderie of other swimmers. It's not like hanging with other photographers and talking about gear.  In the water you're fast or you're not.  It's obvious to everyone in the pool.  

I'm heading out to finish up a photographic job this afternoon.  I'd much rather be swimming in the WHAC pool or over at Barton Springs.  I just didn't have anything to say about photography today.  Imagine that.  

Summer is here.  I think I'll buy a waterproof camera and attach it to a kick board.  That should be fun....

The Temple of Aqueous Joy.

Boundaries are good.  Especially between lanes.

All images taken with the lowly Panasonic G3 camera and the even lowlier 14-45mm lens.

Photography is our ultimate, personal time machine. Use it often. Use it wisely.

Contax G2.  21mm Lens.

Leica M7.  50mm lens.

Hasselblad 500 series.  80mm lens.

Life flies past faster than you can imagine.  One minute you're changing diapers and then next minute you look up and that same person is asking you for the car keys.  And in the end you have the experiences and the souvenirs.  And the souvenirs are mostly the photographs you were prescient enough to take.  And believe me, which camera you use doesn't matter in the least...

Hello Sony !!!! Where the heck are your wide angle lenses for the a77 and a57 APS-C cameras ?????

Image taken with the Sigma 10-20mm 4-5.6 EX DC

I mostly shoot portraits so when I switched camera systems to the Sony a77 and then added the a57 I made sure all my portrait focal lengths were covered.  I bought the 16-50mm 2.8 zoom lens and I think it's marvellous; sharp and snappy at all focal lengths.  I also bought the 70-200mm 2.8 G lens and it's capable of making great images as well.  Then I went in and backfilled with some inexpensive but surprisingly good single focal length lenses such as the 30mm DT macro, the 35mm 1.8 DT, the 50mm 1.8 DT, the 50mm 1.4 and the 85mm 2.8.  All of them have proven to be good lenses for the system.  All are capable of professional results.  But there's a blind spot in the Sony APS-C lineup. The only lens wider than the 16-50mm (FF equivalent = 24mm to 75mm) is the 11-18mm.  The focal length range is right what I'm looking for but the lens is obviously a re-badged Tamron 11-18mm zoom lens and I've been down that road before.  I owned the Canon version and it was barely usable, at best. 

I didn't think much of it until a client asked me to shoot a new architectural project he'd just finished.  It's a grocery store for a well known, national chain.  We need to photograph multiple shots of the exterior and, a few weeks from now, multiple shots of the interior.  In the Canon shooting days I could rent a 24mm shift lens and do most of my work with that.  I'd round out the mix with the old 20mm lens.  But the Sony catalog doesn't include any tilt/shift lenses and since it's not a big part of my business I am loathe to buy them.  Especially when I can do most of my corrections in PhotoShop.  But I do need a clean, sharp lens to start with.  That, and a good ladder...

I shot all the exteriors with the 16-50mm lens.  The profiles in DXO and in PhotoShop CS6 both work very well. The image files come out with a high degree of sharpness and no discernable geometric distortion.  If I shoot from a ten foot high vantage point I don't need to do a lot of "keystone" correction either. When I'm shooting the exteriors and need a wider view than that offered by the 24mm equivalent focal length of the 16-50mm I can always move back to get in more.  But when I head inside it's another story.  I want to be able to go as wide as a standard 20mm or even an 18mm to do justice to the interior space.  

I've been reading up on various alternatives to the Sony 11-18 and I was optimistic about a lens made by Sigma.  It's a 10-20mm f4-5.6.  I headed over to Precision Camera to see if they had one in stock and not only did they have the lens but the Sony rep was there for a promotional event so I gave him and earful too.  He readily agreed that the current lens wasn't an earth-shaking game changer but suggested that Sony is hard at work making their own lens and that all indications are it will be good.  Nice to know but it won't be available for a while  and certainly not by next week when I need it.  I conferred with my personal sales associate, Ian, and ended up walking out the door with the Sigma 10-20mm.  Ian told me I could bring it back within 30 days for a refund, if not thoroughly satisfied (another reason I shop there....).

I had three hours before I was expected home for dinner so I put the lens on the front of the a77 I had in the car and started walking through downtown.  (I did stop at the big, Whole Foods headquarters to have magic almond bar and a good cup of coffee before I got down to lens testing business.  A man has to have priorities).

The handling and build quality of the Sigma is as good as anything out there, short of a Leica or Zeiss lens.  The lens yields sharp images when I focus in the right places and the color and contrast is good.  The only troubling characteristic is the distortion on the extreme edges and the extreme corners.  I'm going to use the Adobe lens profiler to try and make a corrected profile for the distortions.  Unless I can find a profile that someone else has already made.  I think there may also be a profile of the combination of the Sony camera and the Sigma lens in the latest DXO software.  If I can correct the corner and edge distortion I'll be pretty darn happy. The lens is already a much better performer than the Sony 11-18 I borrowed several weeks ago to test.

But this brings up the question:  If Sony is really interested in competing with Nikon and Canon, and now even Olympus, why haven't they filled this important gap with something decent?  Even if they had a really good lens that was just 12-20mm with a slow aperture but really good performance they'd be way ahead of the game.  I was told that Sony owns a big stake in Tamron and Tamron recently rolled out a 10-24mm that supposed to be much better than the 11-18 as well.  At the very least they should re-badge that lens...

I'd love to shoot nothing but portraits but I live in work in a second tier market and it pays off to be able to offer good clients a wider menu of services.  From the walking tests I've done today I'm confident I can pull off what I need to do with the Sigma lens.  But I shouldn't have to.  There are enough great solutions out there that Sony should have this covered.  My dream lens for wide angle would be a prime 12mm f4 that's designed and made by Zeiss.  It doesn't even need to autofocus as long as it has an accurate focus scale on it.  With a super sharp, 12mm lens stopped down to f8 and hanging in front of a 24 megapixel sensor it would be a zone focusing dream.  Add in effect focus peaking and you're absolutely there.

 This image is a 10mm image that was originally tilted back to include the building in the background and then quickly corrected in post.

This image was taken at 20mm.  And left uncorrected and without processing.

I'd read in one of the poorer reviews about the Sigma 10-20mm that flare was an issue.  There's a vicious glare on  the building, smack in the middle of the frame, but I think the lens does a great job handling it.  10mm.

While there is some linear distortion, at the widest setting I think it's pretty well controlled and at most focal lengths is pretty easy to correct.

Snappy and sharp at f5.6 if what I'm seeing.

 10mm corrected in Lightroom 4.2.

By the end of my walk I had pretty much talked myself into keeping the lens.  What I was really looking for is good performance at 14mm.  That's the equivalent of 21mm in full frame and that corresponds to the Zeiss 21 ZE lens I used on the Canon.  When I shot at 14mm I was very happy with sharpness and contrast.  If I can make the distortion corrections I'll be happy.  And at about 1/4th the price of the Zeiss lens.  More tests, under duress, tomorrow.

Don't settle for whatever the manufacturer wants to throw at you.....

Kirk's Amazon Author's Page.