I have been enjoying shooting with DSLRs for quite some time now and while I am very happy with the cameras and lenses I use, I just think that we have not been seeing major breakthroughs in new DSLR cameras. New cameras pack more resolution, faster frames per second, better video features and other bells and whistles, but nothing innovative and revolutionary that changes the way we shoot. With Sony entering the DSLR market rather late in 2006 (after acquiring Konica Minolta), it was tough to compete against the long-established Canon and Nikon cameras. Sony introduced a few DSLRs with great features at a competitive price and secured itself the #3 market share spot in DSLR sales globally, mostly with lower-end DSLR camera bodies. With a rather slow adoption rate and a limited choice of lenses and accessories available, the company quickly realized that its only way to challenge the big two was to innovate. In August of 2010, Sony announced its first “Single-Lens Translucent” (SLT) cameras – the Sony A33 and A55. While the concept of a translucent mirror is not new (in fact, Sony calls it “translucent” for marketing purposes, because it is actually supposed to be “pellicle mirror”), Sony was the first to design it to work with an electronic viewfinder. Its first SLT cameras were a success, so Sony decided to embrace the technology and take it a step further with the new Sony A77 and A65 cameras. Going forward, we will most likely not be seeing any more DSLR cameras from Sony, since its management already expressed commitment to this new breed of cameras. We should be seeing more cameras from Sony with translucent mirrors, including high-end, full-frame models.
The Sony SLT-A77 was kindly provided by B&H – the largest photo reseller in the world that I personally use to buy my photography gear.
1) Sony SLT-A77 Specifications
- 24.3 MP best-in-class resolution
- 2nd Generation Translucent Mirror Design directs light to both the image sensor and the Phase Detection AF sensor simultaneously
- World’s first OLED viewfinder with 2359K dots for amazing resolution and high contrast ratio for incredible depth
- Rugged, magnesium alloy body
- Three-way tilt/swivel LCD screen
- In-camera HDR mode
- Built-in GPS
- 1200-Zone exposure metering
- Built-in Flash
- Continuous shooting at up to 12 frames per second
- Full HD Movie modes at 60p, 60i, or 24p with full exposure control
- Full-Time Live View in LCD or EVF
- Multi-frame NR, Panorama and 3D Panorama Modes
- ISO 100-16000 sensitivity
- Upgraded BIONZ® image processor
- In-camera image stabilization
- 19-point AF with 11 cross-type sensors
- AF Micro Adjust Capability
- 3 inch LCD monitor with 921K dots
- Dynamic Range Optimizer mode
- Advanced sensor Anti-Dust Technology.
- Face Registration and Detection
- Up to 1/8000 shutter speed
- Shutter rated for 150,000 actuations
Click here to download the above photograph in 1920×1200 Widescreen Wallpaper format.
As you can see, the camera packs some very impressive features when compared to Canon and Nikon rival products. Not only does the Sony A77 have the highest APS-C sized sensor on the market today, but it also comes with great built-in features such as built-in GPS (without the need to use external GPS devices), in-camera image stabilization, a plethora of image capture and image editing modes, high-resolution OLED viewfinder and much more.
Detailed technical specifications for the Sony A77 are available on Sony.com.
2) Camera construction, handling and ergonomics
Unlike the square and flat design of the previous-generation Konica / Sony DSLRs, the Sony A77 features a brand new, modern look with a stylish design. The top of the camera is a lot more round and curved, giving a sleek look to the camera on the front, while the curvy back resembles some of the Canon DSLRs. Camera front has a simplistic layout with one preview button, lens release button and focus mode dial. A large AF illuminator (located on top, between the grip and the lens mount), along with an IR receiver (located on the grip) are also visible on the front of the camera.
Like other higher-end DSLRs, the Sony A77 features two dials, one in front and one in the back for controlling exposure and some camera settings. The design of the On/Off switch, along with the two medium-sized buttons located right next to it (exposure compensation and ISO), is clearly borrowed from Nikon DSLRs. Along with a few other buttons on the top, the camera also features a top-panel LCD, which can be illuminated at night by pressing the light bulb button to the right of the LCD. The typical PASM dial with a bunch of camera modes and presets is located to the left of the camera. The typical Sony Alpha hotshoe sits together with a silver microphone in the center:
Speaking of the hotshoe, I found the proprietary Sony Alpha hotshoe to be inconvenient and annoying. I do not understand why manufacturers feel they need to reinvent the wheel when it comes to simple things like this. While there is an adapter available to convert the Alpha hotshoe to a regular one, I did not get a chance to obtain this adapter and hence could not use the camera with my PocketWizard radio transmitters to trigger off-camera flash.
The back of the camera is loaded with plenty of customizable buttons, along with a joystick for menu and image navigation. To be honest, I found the button layout to be poorly designed. I had a rough time getting used to the buttons, even after two months of shooting with the camera. I am perfectly fine with where the Menu button is, but the rest are just all over the place. The joystick is another poor design choice in my opinion. I always had a rough time using joysticks on cameras – the joystick that Nikon uses on their camera grips is horrible and I never liked the joystick that Canon uses on its DSLRs either. I prefer Nikon’s big multi-purpose navigation button and Canon’s rotary dial. The design, layout and navigation of the Sony A65 are much better, in my opinion.
My negative experience with the button layout and the joystick, however, was compensated by the beautiful three-way tilt/swivel LCD and the stunning OLED viewfinder. The articulated LCD has a very unique design that gives the freedom to rotate the LCD pretty much any way you want. You could set the LCD up backwards for protection, or like a traditional LCD. You could tilt it to the side or flip it down or you could even set it up to display what you are shooting right in front of the camera. The camera is smart enough to flip the image on the LCD, so you won’t find yourself looking at yourself or at your subject upside down. As I have already pointed out, the OLED viewfinder is absolutely stunning. After being so used to an optical viewfinder that always shows the same thing with very little customization options, my experience with Sony’s high-resolution electronic viewfinder (EVF) was beyond positive. In fact, the OLED viewfinder was the very first thing that got me glued to the Sony A77 right after I got the battery charged. I have had some experience with electronic viewfinders before, but none of them even remotely compare to this one. It is mind boggling to think that this OLED viewfinder has 2.4 million dots – compare that to 921,000 dots used on the 3 inch LCD screen! But wait, it doesn’t stop there. The OLED viewfinder size that Sony used on the A77 has a 0.73x magnification; compare that to the 0.63x magnification on the Nikon D7000 or 0.70x magnification on the Nikon D3s. So not only do you get a beautiful-looking rending of live view and images inside the viewfinder, but it is also bigger than what most other DSLRs have.
The beauty of the electronic viewfinder when compared to an optical one is that you see everything live. With an optical viewfinder, as soon as you turn on live view, the viewfinder is blocked by the mirror. You look at the live and customizable data inside the viewfinder, frame your shot and take a picture. No loud mirror slap, no extra vibrations, you only hear the camera shutter. If you are used to a DSLR, this is a totally different experience. I won’t go into much detail about advantages and disadvantages of an electronic viewfinder and how it compares to an optical viewfinder (maybe in a separate article), but one thing I am confident about – electronic viewfinders are the future. Yes, there are some serious limitations with EVF today, especially when using them in low light situations, but I believe it is a matter of time until those issues are addressed.
Another key advantage of the A77, in my opinion, is built-in GPS. Instead of ripping people off like Nikon and Canon are doing with GPS-ready connectors that require cables and expensive external GPS devices, the Sony A77 has a GPS unit integrated into the camera. Although I often need the GPS functionality to save places I have been to, I simply refuse to use an external GPS device on my Nikon cameras. We have seen point and shoot cameras from both Canon and Nikon with integrated GPS and yet they are blatantly refusing to add it to DSLRs. We get it, they want to sell us more accessories that get frequently get lost and broken. But how long will it continue? Thanks to pioneers like Sony, not long, or they will start losing their customers. Some people say GPS drains batteries. True, it does. But if you do not want to use it, simply turn it off and the problem is solved. That is not an excuse for not including it in the camera.
Speaking of batteries, the 7.2V InfoLithium battery is rated at 470 images when used with the OLED viewfinder and 530 images with the LCD monitor. This is expected, considering how many more pixels there are on the OLED screen compared to the LCD. However, these numbers are quite poor when compared to the Nikon D7000, which is rated at a whopping 1050 shots.
The Sony A77 measures 142.6x104x80.9mm, which is bigger than the Nikon D7000 that measures 132x103x77mm, however, it only weighs approximately 650 grams, which is 40 grams lighter than the D7000. The camera is fully weather sealed and has a solid magnesium alloy body protecting the front and the back of the camera (top is plastic). As for external camera connectors, the Sony A77 has plenty of them, from flash sync to USB and HDMI.
3) Camera Sensor and the new BIONZ Processor
As of January, 2011, the Sony A77 has the world’s highest resolution APS-C (23.5 x 15.6mm) sensor. With a whopping 24.3 Megapixels, its pixel density is very high, with a pixel size of just 3.89 microns. A high resolution sensor is generally a good characteristic of a camera, because it can resolve a lot of detail, but high pixel density equates to small pixels, which ultimately result in more noise, or low Signal to Noise Ratio (SNR). Now this last sentence is subject to heated debates among the photography community lately. I have written a detailed article on the benefits of a high resolution sensor, explaining why small pixels are not necessarily bad. In summary, if you were to take two cameras, one with a high resolution sensor (smaller pixels) and one with a lower resolution sensor (larger pixels), the former might look very close to the latter in terms of noise, once the image is normalized to the same resolution or print size. That’s because noise is reduced during the down-sampling process, as explained in detail here. While the camera with a lower resolution sensor has higher ISO sensitivity modes, the high resolution camera has sharper images when down-sampled (assuming the lens can resolve enough detail). The pros and cons list expands to many other areas such as file sizes, processing speed, storage requirements, etc.
So, where does this all put the 24.3 MP Sony A77 sensor? Is it truly advantageous to have such a high resolution APS-C sensor, or did Sony make a mistake by reigniting the megapixel war? My initial reaction to the high resolution sensor was rather negative, because I knew that it would impact the low-light performance and the speed of the camera. At the same time, I could not wait to try shooting 24 megapixel landscape images at ISO 100. After a detailed lab and outdoors analysis, along with comparison to other cameras, I came to the conclusion that the sensor performance is surprisingly good. True, high ISO shots do look very noisy at pixel level above ISO 1600, but once you down-sample images to around 16 MP (which is what Nikon D7000 has), noise is significantly reduced and does not look bad. It is still noisier than the Nikon D7000 at 16 MP, but not much worse. This is something I expected to see, because Nikon has a lot more experience with noise reduction at high ISOs and its image processing pipeline is clearly superior at anything above ISO 800.
The real advantage of the A77 sensor, however, is its low ISO performance. Images at ISO 100 look stunning, with plenty of details, colors and dynamic range to play with. As long as you are using good lenses that can resolve so much detail, you will not be disappointed with the sensor performance. With so much resolution, this is the camera that will make landscape and fashion photographers happy.
Please note that I only shot RAW with the Sony A77 and processed all images in Lightroom and Photoshop, with the latest version of Camera RAW. I noticed that Sony applies some heavy noise reduction on JPEG images that results in detail loss, so I switched to RAW pretty much from the start.
To make the crazy 12 FPS speeds possible with the 24.3 sensor, Sony had to beef up its image processor. The A77 ships with an upgraded Sony BIONZ image processor that not only does a great job in keeping up with such enormous throughput needs, but also allows for in-camera image processing and tweaking of final output. You can even combine multiple exposures for HDR and 2D / 3D Panoramic effects. Furthermore, the BIONZ processor is fast enough to cope with 1080p high definition video at 60 frames per second – something neither the Nikon D4, nor the Canon 1D X can do, being top-of-the-line DSLRs.
4) Ease of Use
I have never used a Sony Alpha before and I did not know what to expect in terms of the learning curve. To my surprise, despite some functional differences and slight annoyances here and there (like the direction of the front and rear dials is reversed compared to Nikon and cannot be changed), I found the Sony A77 quite easy to use and operate. Its default settings were already good enough for my photography needs and aside from changing image format from JPEG to RAW and playing with a couple of other settings, I was quite happy with the results. The menu system has a horizontal structure like Canon DSLRs and there are only a couple of sub-menus to deal with. Everything in the menu is descriptive and easy to understand, nothing like the cryptic menu system on the Olympus E-PL3.
The camera responsiveness is good, although I had a few occasions when the menu system, image playback and EVF to LCD switching were lagging behind a little. Although updating camera firmware helped with the lag a little, it did not seem to completely eliminate it. Quickly rotating the dials on the front and the rear of the camera is still rather laggy.
5) Autofocus Performance and Metering
With 19 focus points and 11 cross type sensors, the Sony A77 autofocuses quite well in most situations. I tried a number of different Sony and Zeiss lenses on the camera and all (except one Sony lens that had a severe back-focus problem) seemed to perform reliably well when photographing portraits and landscapes. Phase-detect AF was mostly quick and accurate, even in some low-light situations. I occasionally got out of focus images here and there, but the hit/miss ratio was not anything excessive; I would say on par with what I typically get with Nikon DX cameras. I found the implementation of continuous AF and subject tracking quite poor, on the other hand, especially when compared to Nikon DSLRs like the Nikon D7000. I tried to take some pictures of my kids running around in a park in AF-C (continuous) mode and the camera had a tough time keeping focus (using 50mm and 85mm prime lenses). Many images came out blurry and it felt like the camera had some sort of a focus lag when photographing fast-moving subjects. I have never experienced this sort of erratic autofocus behavior with any Nikon DSLRs, including entry-level models like Nikon D5100. Other than that, AF seemed to be more reliable in continuous mode with slower subjects.
With an amazing speed of 12 fps, you would think the Sony A77 could challenge the big guys like Nikon D3s. Well, note quite. You can only get 12 fps when shooting in Continuous Priority AE mode, which puts some limitations on lens aperture. For continuous AF to work at 12 fps, lens aperture needs to stay wide open or the phase detect sensor might not receive sufficient light. On a traditional DSLR, lens aperture is always wide open and the lens only stops down right before taking the picture. This is a necessary measure, especially when shooting at high frame rates in continuous mode. The same applies to the Sony A77, except it cannot quite keep up with such fast speeds and therefore the lens aperture must stay wide open. If you want to shoot continuously without this limitation, then you could either switch to AF-A / Manual Focus modes, or you could switch to Standard Continuous mode that is limited to 8 fps. On top of this, unlike DSLR cameras that let you see the action through the optical viewfinder in between shots, the Sony A77 blocks the view inside the viewfinder by playing back previous images. This is problematic for high speed action photography, so sports and wildlife photographers should be aware of this limitation. Still, 8 fps with continuous AF is a very impressive speed.
Now let’s talk about one more factor that impacts the performance – camera buffer. With huge 24.3 MP files and high frame rates, it would be difficult for the camera to maintain those high speeds due to the sheer amount of memory that is required to hold so many images. Even the best SD cards today are not fast enough to keep up with such speeds. When shooting in RAW at 12 fps, the buffer fills up in a little over a second and then crawls to extremely slow speeds, roughly 1 fps. It then takes about 12-15 seconds for the buffer to transfer all the images to the card. Switching to smaller JPEG files and slower speeds helps, but it is still pretty clear that the buffer size on the camera is too small for such high resolutions and fast speeds.
As for metering, I had a mixed experience with the A77. When it comes to matrix metering, one great thing about Nikon DSLRs is their exposure consistency, even in changing light conditions. Consistency is a key word here, because the Sony A77 does not seem to have it when photographing people. I had a few cases when I shot the same subject with the same background twice in multi-segment metering mode (which is equivalent to matrix metering on Nikon) and ended up with two different exposures (one good and one underexposed). I did not see the same problem when photographing landscapes though – multi-segment metering did a pretty good job and I rarely had to resort to exposure compensation.
6) Built-in Image Stabilization
One distinct feature of the Sony Alpha cameras that differentiates them from Nikon and Canon DSLRs, is their in-camera image stabilization. I won’t go into details on advantages and disadvantages of in-camera image stabilization vs lens image stabilization, but one thing for sure – it works well, especially when using fast aperture prime lenses. Canon and Nikon DSLRs only offer lens image stabilization, so you have to watch your shutter speed when using non-IS lenses like Nikon 50mm f/1.4G. You do not have to worry about that when using any lens on the Sony A77. Sony calls its image stabilization technology “Steady Shot” and it can be turned on or off for capturing images or video through the camera menu system. The in-camera image stabilization is silent and you do not hear the same hum you normally hear on Nikon lenses when image stabilization is engaged.
7) Movie Recording
The Sony A77 has very impressive video features that will definitely appeal to videographers. With a high-quality 1080p full HD video, the camera is capable of recording videos at 24p, 60i and 60p modes in AVCHD / MP4 (MPEG-4 AVC H.264) format. There is a separate “Movie” silver video record button on the camera used for starting and stopping video recording. Movies are limited to 29 minutes and the battery should last for up to three hours of continuous movie recording. Full exposure control is available in movie control mode, but continuous/full-time autofocus does not work in that mode. If you want full-time autofocus while shooting videos, then the only option is to use one of the PASM modes instead, at which point the camera takes over the exposure control of videos.
8) Sweep Panorama Mode
While I personally would not trust the camera to take panoramic shots for me (I do it manually through post-processing and panoramic software, as detailed in my “panoramic photography tutorial“), I tried using the sweep panorama mode on the Sony A77 and I was surprised by how well it worked. It took me a few tries to successfully do a full panorama, but once I figured it out, it was an easy process to follow. Images were stitched well and I did not see any major artifacts or stitching problems in the final images. Here is a sample panorama taken with the camera:
Looks like the sweep panorama mode is not designed for serious work, because the resolution of the panoramas is limited to 12416×1856 in wide mode, 8192×1856 in standard mode (for horizontals) and 2160×5536 in wide & 2160×3872 in standard (for verticals). That’s pretty low, considering the native resolution of 6000×4000. On top of that, panoramas are also captured in processed JPEG format, limiting the options for tweaking the image output in post-processing. I prefer to shoot my panoramas frame by frame in RAW format, then use panoramic software for stitching. That way not only do I get more control over panoramas, but I also get a lot more resolution in the final image. In one case, I was able to stitch 11 vertical images in one row and got a massive panorama with a 22450×5890 resolution, which is almost twice bigger than what the automatic sweep panorama can deliver.
9) Built-in GPS
The built-in GPS on the Sony A77 works very well. I had it turned on at all times when shooting outside and it provided accurate GPS results on every image. If you are interested in seeing exactly where each image in this review is taken, the GPS data is available as part of EXIF data. Latitude, longitude, altitude, direction, GPS timestamp and other related GPS data is automatically embedded into each image as part of metadata.
In my opinion, all cameras should have the GPS capability. It is always nice to be able to go back and locate the exact spot from where the picture was taken. Sometimes I look at some old pictures and want to find where I took them, but because I did not put any notes on exactly where I physically was, I cannot travel back to find the location. In addition, with all the GPS-ready applications such as Lightroom and photo sites like Flickr, Picasa and others, GPS data is getting more and more useful. Some websites even provide a Google map of where the photo was taken when a picture is uploaded.
10) Lens Compensation
Another very useful feature for JPEG shooters out there, is the ability to reduce lens issues such as chromatic aberration, distortion and vignetting right from the camera. This is a very similar feature as Lightroom’s Lens Corrections module. The camera stores profiles of lenses in camera firmware and when a new lens is released, Sony will push the lens profile via a firmware update. If you shoot RAW and use third party software like Lightroom, chromatic aberration and distortion corrections will be discarded upon import, because the data is stored as metadata (similar to Nikon’s RAW/NEF files). However, if you enable vignetting correction (Sony refers to vignetting as “shading”), then those corrections are done at the image processing pipeline, which means that corrections are directly written into the RAW data. Considering that Adobe releases lens profiles for Sony cameras and lenses, this sort of irreversible correction on RAW level might not be a good idea – you do not want vignetting to be corrected in two different places. Therefore, I would keep “shading” correction off.
11) Dynamic Range
At ISO 100, the dynamic range the Sony SLT-A77 offers is very good. Although I did not perform any scientific tests to measure the dynamic range, I tried to recover some shadow details from a high contrast RAW image sample and results were comparable to what I got with the Nikon D7000. DxOMark ranks the Sony A77 at #10 among all cameras with 13.2 EVs, putting it ahead of many medium format cameras like Phase One P40 and P65 Plus (with Pentax K-5 and Nikon D7000 topping the chart).
Don’t forget that dynamic range decreases as you increase ISO, so if you want to be able to recover the maximum amount of details, you should be shooting at ISO 100. This is especially important for HDR photography – always shoot at base ISO of 100 and use a tripod.
The built-in Dynamic Range Optimizer (DRO) is very similar to Nikon’s Active D-Lighting – it only applies to JPEG images. Since I shoot RAW, I had DRO turned off. If you shoot JPEG, it is probably best to keep DRO on for the best results. As for the HDR tool, I personally did not use it either, since I believe that HDR should be properly done through HDR software instead. HDR effects can only be applied to JPEG images as well.
Let’s see how the camera performs at low and high ISOs, click the next page of the review.
12) ISO Performance at low ISOs (ISO 100-800)
Some technical junk:
- White Balance: Auto, changed to “Custom”: 4600 Temp, +26 Tint in Lightroom
- ISO: 100
- Lens Used: Zeiss 16-80mm f/3.5-4.5 ZA DT
- EXIF information is preserved in the images
- Aperture: f/8.0
- Focusing was performed through Live-View Contrast Detect
- Long exposure NR: Off
- Image Format: RAW
- Imported images into Lightroom and cropped to 100% – no resizing was performed in Photoshop, unless indicated
- No exposure adjustments were performed in Lightroom (besides White Balance)
- Lightroom sharpening: 25, 1.0, 25, 0 (default)
- Lightroom export: sRGB JPEG Quality 80
Let’s take a look at how the Sony A77 performs at low ISOs. Here are some crops at ISO 100, 200, 400 and 800:
ISO 100 and 200 images look very clean.
ISO 400 adds a little bit of grain, but nothing to worry about. ISO 800 doubles the amount of noise from ISO 400 and we start to see larger grains in the shadows.
13) High ISO Performance (ISO 1600-16000)
High ISO performance is a very important measure of DSLR sensor quality. Here is how the Sony A77 performs at high ISO levels between ISO 1600 and 16000:
ISO 1600 adds significantly more noise than ISO 800, but the image is still usable, even at 100% view. Shadow areas have much more noise, but the detail is preserved. At ISO 3200, however, grain gets much bigger, I would say about twice bigger in size, and the details in the shadow areas start to disappear. Colors are definitely affected at ISO 3200.
Anything above ISO 6400 looks pretty bad at 100% pixel view – details are completely lost in the shadows and there is a significant loss of detail in well illuminated parts of the image as well. ISO 12800 and 16000 are downright unusable, in my opinion.
14) ISO Performance Summary
This is a clear demonstration of what happens with high resolution cameras that have very small pixels. While the low ISO performance is very impressive, ISO levels above 1600 show a significant amount of noise throughout the image. I would say that ISO 1600 is my threshold for the amount of acceptable noise that can be later cleaned up in post-processing. However, keep in mind that we are looking at the above images at 100% view, or “pixel level”. As you will see in the next page of this review, once the 24 MP image is down-sampled to smaller resolution, the camera actually performs surprisingly well when compared to other lower resolution cameras.
Compared to Sony NEX-5n
Let’s see how the Sony A77 compares to the mirrorless Sony NEX-5n that has a high quality 16.1 MP sensor.
15) Sony A77 vs Sony NEX-5n Low ISO Comparison
Both cameras perform equally well at ISO 100.
ISO 200 is a tad cleaner on the NEX-5n.
The same is true for ISO 400.
At ISO 800, the NEX-5n definitely appears cleaner throughout the image.
16) Sony A77 vs Sony NEX-5n High ISO Comparison
Let’s see what happens at higher ISOs:
Sony A77 is definitely much noisier at ISO 1600 than the NEX-5n, mostly due to the size of the grain.
At ISO 3200 the Sony A77 loses most details in the shadows and the grain appears to be about twice bigger in size when compared to NEX-5n.
There seems to be at least a full stop of difference between the cameras at these high ISO levels. ISO 6400 and higher are unusable for my taste at 100% view.
17) Sony A77 vs Sony NEX-5n High ISO Comparison (Down-Sampled)
Now let’s see what happens when the Sony A77 images are down-sampled to match the NEX-5n resolution. Please note that although the below images say Sony A65, the sensor performance is actually the same, because both cameras use exactly the same sensor and image processing pipeline.
ISO 800 looks very clean on both cameras.
The same is true for ISO 1600 – both look about the same.
Again, ISO 3200 is comparable between the two, with a slight advantage of NEX-5n.
At ISO 6400, the Sony A77 has noticeable loss of colors and lots of chroma noise in comparison.
18) Sony A77 vs Sony NEX-5n Summary
While the low ISO performance of both cameras is very impressive (with Sony A77 having the lead due to more megapixels), the smaller resolution sensor on the NEX-5n clearly shows superior performance at ISO 1600 and above, when viewed at pixel level (100%). The difference in ISO performance increases at higher ISO levels to NEX-5n advantage and reaches over 1 stop of difference at ISO 6400. However, when Sony A77 is down-sampled to NEX-5n resolution, things definitely get more balanced out and there is very little difference between the two at ISO 800, 1600 and 3200. Images at ISO 6400 and higher are unusable on the A77 and there is lots of color loss, so the NEX-5n still has an advantage there (although I would never shoot at such high ISOs on either camera).
One other thing to note here, is that the NEX-5n sensor receives more light than the A77, because it has no mirror that blocks any of the light. Sony had to boost the ISO performance of the A77 further, because it needed to compensate for the light loss (which is roughly 2/3 to 1/2 of light loss). That’s why the NEX-7 that has exactly the same 24 MP sensor performs better than the A77.
Compared to Nikon D700
While the below comparison is not fair due to sensor size difference (full-frame D700 vs 1.5x crop factor A77), the resolution of the Nikon D700 is much lower, so you might find down-sampled comparisons pretty interesting to look at.
19) Sony A77 vs Nikon D700 Low ISO Comparison
As expected, the Nikon D700 looks very clean, thanks to its much bigger sensor and pixels.
There is already some noticeable difference at ISO 200.
ISO 400 on the D700 continues to look noise-free, while A77 has some visible noise in comparison.
As we increase ISO to 800, the difference is even bigger.
20) Sony A77 vs Nikon D700 High ISO Comparison
Nikon D700 completely destroys the A77 at IS levels above ISO 800 (pixel level performance).
I would say there are about two full stops of difference between the Sony A77 and the Nikon D700.
21) Sony A77 vs Nikon D700 High ISO Comparison (Down-Sampled)
Now don’t forget that the above images are shown at 100% view, meaning pixel level performance. That’s not really a fair comparison, because the Sony A77 has a lot more resolution and its images can be down-sampled to 12 MP to significantly reduce noise. Let’s now take a look at what happens when we do exactly that:
ISO 800 performance is comparable between the two, with a slight advantage on behalf of Nikon D700.
The same is true for ISO 1600 – both look somewhat comparable, with a cleaner image on the D700.
Plenty of details on both images at ISO 3200, with a cleaner image from the D700.
And the Nikon D700 performs much better at ISO 6400 and higher levels, mostly due to heavy detail and color loss on the A77.
22) Sony A77 vs Nikon D700 Summary
The above comparison is very interesting to look at. As expected, the Sony A77 sensor is no match to Nikon D700′s legendary full-frame sensor when the image is viewed at 100% (pixel level). But let’s not forget that the Sony A77 has a lot more resolution than the Nikon D700, so 100% pixel performance is not a fair comparison. A more balanced and fair comparison would be to down-sample the 24 MP image from the Sony A77 to 12 MP and then compare the two. As can be seen from such a comparison above, the Sony A77 performs very well at 12 MP between ISO 800 and ISO 3200. The Nikon D700 still looks cleaner, especially at higher ISO levels, but that’s expected from a full-frame sensor. The Sony A77 images at ISO 6400 have too much chroma noise and heavy loss of colors.
Summary and Image Samples
Coming from a Nikon DSLR background, I did not know what to expect from the newly released Sony SLT-A77 camera. Its impressive performance characteristics, high resolution and bundled features were the reason why I decided to give Sony a try. After several months of using the camera in various environments, I am happy to say that I am very impressed by this solid and highly capable camera. Sony chose the path of innovation to differentiate itself from the competition and put a lot of effort into making the translucent mirror (SLT) and electronic viewfinder (EVF) technologies work, challenging the outdated 60 year old SLR. Its implementation of the cutting-edge OLED electronic viewfinder contributes to the success of the SLT line. I have tried out other cameras with electronic viewfinders before (including the new Nikon 1 V1) and none of them even remotely compare to the gorgeous OLED viewfinder on the Sony A77. I was at first somewhat skeptical of an electronic viewfinder, but my view changed rather quickly after using the camera. In my opinion, seeing the live view screen both on the LCD and inside the viewfinder without having to lock up the mirror outweighs the disadvantages of the EVF and ability to see exposure changes live with plenty of useful overlay information can be invaluable, especially for beginners.
Its high resolution 24.3 MP sensor yields impressive images at low ISOs. However, higher ISO levels (especially above ISO 3200) tend to produce too much noise due to high pixel pitch. There is also a considerable amount of detail and color loss, which is expected from such a high resolution sensor. As I have explained in my “benefits of a high resolution sensor” article though, these performance differences are greatly reduced when images from the Sony A77 are down-sampled to a smaller resolution. Coupled with the upgraded BIONZ image processor, the Sony A77 can deliver up to 12 frames per second of full-resolution images. Sadly, due to the sheer size of high resolution images, especially in RAW format, the buffer on the camera is too small to accommodate more than a second worth of images.
The AF performance of the camera is good, but does not quite match the AF performance of a Nikon equivalent such as Nikon D7000, especially in continuous drive mode. Wildlife and sports photographers should probably stick to Nikon/Canon DSLRs for now, until Sony addresses these AF issues (Sony does not yet have a good selection of long telephoto lenses anyway). As for ergonomics, I find the button placement on the back of the A77 to be rather random, making it difficult to efficiently use the camera. While many of the buttons are programmable, I just think that Sony should have followed a simpler layout like on the Sony A65. On a positive note, the tilt/swivel LCD implementation is the best I have seen in any camera to date. While there are some lags and annoyances here and there, I believe Sony can iron most of them out via future firmware updates.
Overall, I am very impressed by the Sony SLT-A77 and I highly recommend it to our readers. I mostly used the Sony A77 for photographing landscapes and I can honestly say that I would not hesitate to use it professionally for my work. In fact, some of the images I captured with the Sony A77 have already made their way into my portfolio.