Sony A550 Review
Our Dynamic Range measurement system involves shooting a calibrated Stouffer Step Wedge (13 stops total range) which is backlit using a daylight balanced lamp (98 CRI). A single shot of this produces a gray scale wedge from (the camera's) black to clipped white (example below). Each step of the scale is equivalent to 1/3 EV (a third of a stop), we select one step as 'middle gray' and measure outwards to define the dynamic range. Hence there are 'two sides' to our results, the amount of shadow range (below middle gray) and the amount of highlight range (above middle gray).
To most people highlight range is the first thing they think about when talking about dynamic range, that is the amount of highlight detail the camera can capture before it clips to white. Shadow range is more complicated; in our test we stop measuring values below middle gray as soon as the luminance value drops below our defined 'black point' (about 2% luminance) or the signal-to-noise ratio drops below a predefined value (where shadow detail would be swamped by noise), whichever comes first.
Creative Style options
The graph below shows the dynamic range response from the A550's Creative Styles. They all have slightly different tone curves but deliver similar amounts of dynamic range. While all styles clip at the same point in the highlights the slightly higher contrast used by the B&W, Vivid and Landscape modes means they clip a little earlier in the shadows (and the Portrait setting's lower contrast means it gives a touch more shadow range).
The A550 offers a range of contrast settings for each of its creative styles (the graphs below show the Normal style). As you can see the range from -3 to +3 isn't huge but it does at least allow you some control.
ISO Sensitivity and Dynamic Range
The dynamic range falls steadily as you move up the ISO range and noise eats away at the shadows - highlight range is essentially unchanged. As we've seen with other Sony Alpha models the JPEG dynamic range - particularly in the highlights - is excellent, better than most competitors. Note that in all cases these tests were performed without any of the A550's dynamic range optimization features enabled DRO off).
|Sensitivity||Shadow range||Highlight range||Usable range|
|ISO 200||-5.2 EV||4.2 EV||9.4 EV|
|ISO 400||-4.9 EV||4.2 EV||9.1 EV|
|ISO 800||-5.1 EV||4.2 EV||9.3 EV|
|ISO 1600||-4.7 EV||4.2 EV||8.9 EV|
|ISO 3200||-4.3 EV||4.2 EV||8.5 EV|
|ISO 6400||-3.4 EV||4.1 EV||7.5 EV|
|ISO 12800||-2.7 EV||4.0 EV||6.7 EV|
Dynamic Range compared
As mentioned above the Alpha 550 is one of the better performers on the market, in terms of dynamic range in JPEGs.
|Sony DSLR-A550 (ISO 200)||-5.2 EV||4.2 EV||9.4 EV|
|Canon EOS 500D (ISO 100)||-5.1 EV||3.4 EV||8.6 EV|
|Nikon D5000 (ISO 200)||-4.8 EV||4.0 EV||8.8 EV|
|Pentax K-7 (ISO 100)||-5.7 EV||2.9 EV||8.6 EV|
The wedges below are created by our measurement system from the values read from the step wedge, the red lines indicate approximate shadow and highlight range (the dotted line indicating middle gray).
Experience has told us that there is typically around 1 EV (one stop) or more of extra information available at the highlight end in RAW files and that a negative digital exposure compensation when converting such files can recover detail lost to over-exposure. As with previous reviews we settled on Adobe Camera RAW for conversion to retrieve the maximum dynamic range from our test shots.
As you can see the default Adobe Camera RAW conversion delivers less dynamic range than JPEG from the camera (with a more contrasty tone curve that clips highlights earlier, and fractionally less noise reduction in shadows). The best we could achieve was 10.7 EV of total dynamic range, including around a stop of extra highlight range.
- ACR Default: Exp. 0.0 EV, Blacks 5, Contrast +25, Brightness 50
- ACR Auto: Exp. -1.0 EV, Blacks 0, Contrast -0, Brightness 0, Curve linear, Recovery 9
WARNING: Although ACR was able to retrieve the 'luminance' (brightness) of wedge steps which were previously clipped there's no guarantee of color accuracy as individual channels may clip before others.
As the graphs above show the A550 - like many Sony SLRs - offers pretty good highlight range (the chances are that the A550's ISO 200 is performing the same trick as Nikon and Olympus cameras do, and that Canon offers as an option with its Highlight Tone Priority feature - see this blog post for more information). Although shooting raw can only go so far in recovering truly clipped highlights (which essentially have no tonal data in them to recover) we did find the A550's files to be remarkably pliable when it comes to mild - or even extreme - over exposure, allowing us to pull back what appeared to be featureless highlights by as much as three stops without significant problems. Of course you can't do anything with areas that are totally clipped (in a correctly exposed image there's at most a stop of extra highlight detail), but for overexposed shots it's surprising how much you can rescue from the raw file.
As you can see in the first example below the very brightest clipped areas (the highlight on the metal in the middle right of the crop) aren't recovered, and exhibit the usual color shifts / posterization, but everything else - including areas that appeared to be clipped - have plenty of tonal information hidden away that's easily recovered using negative exposure compensation at the raw stage. This is important, as the A550's metering is far from reliable, often overexposing outdoor scenes by at least a stop. Interestingly you'll also get fractionally less noisy ISO 200 images if you intentionally over-expose and pull it back in raw mode (the sample at the bottom of this page has none of the mild noise often visible in blue skies in correctly exposed ISO 200 raw shots.
|Adobe Camera RAW
|Adobe Camera RAW
-2.5 EV digital comp.
|Adobe Camera RAW
|Adobe Camera RAW
-3.0 EV digital comp.
- 15 Photographic tests (DR)
- 16 Photographic tests (DR)
- 17 Photographic tests
- 18 Compared to
- 19 Compared to (JPEG)
- 20 Compared to (JPEG)
- 21 Compared to (RAW)
- 22 Compared to (RAW)
- 23 Compared to (Higher ISO)
- 24 Compared to (Resolution)
- 25 Compared to (Resolution)
- 26 Kit Lens test
- 27 Conclusion
- 28 Samples
Dec 9, 2009
Aug 27, 2009
Dec 5, 2012
Dec 7, 2012
|Carla... by lickity split|
from Beautiful caucasian female faces
|Lunar New Year Fireworks by Michael L NYC 99|
|Vatican Basilica by wam7|
from Street lights
How confident are you that you can spot a manipulated photo? A recent study at the University of Warwick shows that many people are pretty bad at it.
If you purchased a Leica TL2, do NOT attach Leica's Visoflex electronic viewfinder. Leica is working on a fix, but for now, it's possible the viewfinder will break your camera.
Google just released Motion Stills for Android. Unlike the iOS version, the Android app uses a redesigned video processing pipeline that processes each frame of a video as it is being recorded, creating instant results.
A huge copyright lawsuit between photography firm VHT and Zillow Group is heating up again, as both sides appeal a court ruling that granted VHT $4 million in damages.
European Space Agency astronaut Thomas Pesquet spent 6 months on board the International Space Station where he worked with Google capturing spheric panorama images that are now available in Street View.
It's official. PDN has confirmed with parent company Aurelius that 94-year-old lighting company Bowens is indeed going out of business.
The newly launched firmware version 1.06 fixes AF-issues that can occur with some lenses that are not officially compatible with the MC-11 converter.
Voyager is a waterproof smart light stick you can control entirely from your phone. The light has already blown past its $300K funding goal on Indiegogo.
2018 is the last year Photokina will take place during the traditional end-of-September dates. In 2019, Photokina will take place from the 8th to the 11th of May.
The Canon IXUS 50 (known as the SD400 Digital ELPH in North America) was one of a string of high-performing, pocketable PowerShots of the mid-2000s. In this week's throwback Thursday, Barney casts his mind back to 2005.
A close look at the EOS 6D II's Raw files suggest its dynamic range has taken a significant step backwards compared with the company's recent DSLRs. We look at how much difference this might make for your photos.
With a full-production review unit in our hands, we've got over 100 production samples from the new Canon EOS 6D Mark II to share.
Need a break from your day? Kick back and watch the making of a somewhat unconventional mojito filmed on Canon's new EOS 6D Mark II.
The Bonfoton Camera Obscura Room Lens can turn any room into a camera obscura, projecting the view from your window onto the walls of your room.
Adobe just released version 2015.12 of Lightroom CC, adding support for several new cameras and lenses, and baking in several important bug fixes while they were at it.
In this interview, Chiara Marinai, photo editor for VanityFair.com, explains exactly what she looks for in new photographers and photo submissions. Take notes.
Massive corporation P&G is being sued by a Cincinnati photographer for serious copyright violations. If the courts rules against P&G, the company could pay as much as $75 million in damages.
Snapchat's camera-equipped 'Spectacles' aren't so difficult to get anymore. You can now pick up a pair through Amazon for $130.
A group of thieves has made away with tens of thousands in camera gear through a carefully orchestrated scam through Venmo and Facebook Marketplace.
A portrait lens from 1910 might be coming back to life if two photographers from Germany succeed in a new Kickstarter project—the latest development in the craze to remake vintage optics.
The updated version of Google Glass is called the Enterprise Edition and, as the name suggests, it's not meant for personal use.
Charles Ommanney was once a photographer for presidents George W. Bush and Barack Obama, now he's working for Facebook CEO Mark Zuckerberg.
Image compression software JPEGmini Pro was just updated to handle files up to 128MB. They're calling it "The 1 Feature Hasselblad Owners
Apple was just granted a patent for a camera system that prods, coaxes and manipulates users into taking better group and solo selfies.
The Canon EOS 6D Mark II is a better camera than its predecessor, but how much better? Should you buy one?
The winners of the 2017 Magnum and LensCulture Photography Awards have been announced. Here are the six photographers who took home the top prize in their respective categories.
A NASA study has confirmed what your ears have been telling you: people HATE drone noise. In fact, it was ranked more annoying than that of "any ground vehicle."
This floating bird video isn't edited in post-production. It's the result of the birds wing flap matching the camera's 20fps frame rate.
Adobe released a major update to Lightroom Mobile for both iOS and Android users today.
Could the future of photo and video storage be... alive? Scientists at Harvard have managed to encode a GIF of a galloping horse into a live sample of E. coli.