Sony Alpha SLT-A99 II vs Sony Alpha SLT-A55

In this comparison, we will evaluate the Sony Alpha SLT-A99 II and the Sony Alpha SLT-A55, highlighting the advantages of each over the other, discussing their pros and cons, shared strengths and weaknesses, and providing a rating based on their available features and specifications to assist you in choosing the one that best suits your needs.

Sony Alpha SLT-A99 II was introduced in September 2016 and Sony Alpha SLT-A55 was introduced in August 2010. Let us first list highlights of the models.

Now that we've looked at the most essential specifications and gained a basic understanding of these cameras, we can delve into more details and see the differences between them.

This section shows those features and specifications which are the reason to choose Sony Alpha SLT-A99 II over Sony Alpha SLT-A55.

This section shows those features and specifications which are the reason to choose Sony Alpha SLT-A55 over Sony Alpha SLT-A99 II.

We already listed pros and cons of each model. However, you may also find useful to look at their common strengths and weaknesses shown side-by-side.

Screen

Sony Alpha SLT-A99 II and Sony Alpha SLT-A55 have 3.0" Fully Articulated screens with 1,229k dot and 921k dot resolutions respectively. Fully articulated screen makes cameras selfie and vlogger friendly and generally very useful for video shooting.

Viewfinder

Sony Alpha SLT-A99 II has a built-in 0.51" Electronic viewfinder with 2,359k dot resolution and Sony Alpha SLT-A55 has a built-in Electronic viewfinder with 1,150k dot resolution. They both have 100% coverage.

Sony Alpha SLT-A99 II features a 42.4 megapixel Full Frame BSI-CMOS sensor with dimensions of 35.9 x 24 mm and a total area of 861.6 mm². Its native ISO range is 100 - 25,600 and expands to 50 - 102,400 in boosted mode. Sony Alpha SLT-A55 features a 16.2 megapixel APS-C CMOS sensor with dimensions of 23.5 x 15.6 mm and a total area of 243.4 mm². Its native ISO range is 100 - 12,800 and expands to 100 - 25,600 in boosted mode.

Sony Alpha SLT-A99 II has BSI-CMOS sensor, short for Backside Illuminated Complementary Metal-Oxide-Semiconductor sensor. In traditional CMOS sensors, the wiring and circuitry are located on the front side of the sensor, which can block some of the incoming light. BSI technology flips this design by placing the photosensitive elements (pixels) on the backside of the sensor, allowing more light to reach the pixels. This significantly enhances light sensitivity and improves low-light performance. BSI-CMOS sensors are particularly effective in low-light conditions, as they can capture more light, resulting in brighter and less noisy images. This makes them well-suited for indoor and night photography. BSI-CMOS sensors deliver a higher SNR and reduced cross-talk.

Here is a sensor size comparison chart where you can see how different sensors compare with each other:

Sensor size chart

	Sensor	Dimensions	Area	Aspect Ratio	Crop Factor
	Medium Format	44 x 33 mm	1452 mm2	4:3	0.79x
	Full Frame	36 x 24 mm	864 mm2	3:2	1x
	APS-H	27 x 18 mm	486 mm2	3:2	1.3x
	APS-C	23.6 x 15.6 mm	368.2 mm2	3:2	1.5x
	APS-C (Canon)	22.3 x 14.9 mm	332.3 mm2	3:2	1.6x
	Micro Four Thirds	17.4 x 13 mm	226.2 mm2	4:3	2x
	1-inch	13.2 x 8.8 mm	116.2 mm2	3:2	2.7x
	1/1.7-inch	7.44 x 5.58 mm	41.5 mm2	4:3	4.7x
	1/2.3-inch	6.17 x 4.55 mm	28.1 mm2	4:3	5.6x

Sony Alpha SLT-A99 II is equipped with BIONZ X processor and can take pictures up to 7952 x 5304 resolution. Sony Alpha SLT-A55 is equipped with BIONZ processor and can take pictures up to 4912 x 3264 resolution. It can also take pictures with lower resolution like 3568 x 2368, 3568 x 2368, 2448 x 1624, 2448 x 1376 with 3:2, 16:9 aspect ratios.

Lens Mount

Cameras have Sony A lens mount. Due to Full Frame sensor in Sony Alpha SLT-A99 II its crop factor is equal to 1x, this means that a 35mm equivalent focal length of the mounted lens will be equal to its actual focal length. Due to APS-C sensor in Sony Alpha SLT-A55 its crop factor is equal to 1.5x, this means that a 35mm equivalent focal length of the mounted lens will be equal to its actual focal length times 1.5.

No Low-Pass Filter on Sony Alpha SLT-A99 II

There is no optical low-pass filter (OLPF), also known as an anti-aliasing filter, in front of the sensor on Sony Alpha SLT-A99 II. This results in a slightly sharper image but may also introduce moiré patterns and aliasing artifacts when photographing subjects with fine, repetitive patterns or details.

In-Body Image Stabilization

The cameras have a built-in in-body image stabilization (IBIS). This means that you are still getting vibration reduction when cameras are paired with non-image stabilizied lenses. It also works with lenses with optical image stabilization and in combination can achieve even better compensation.

Built-in GPS on Sony Alpha SLT-A55

Sony Alpha SLT-A55 has a built-in GPS (Global Positioning System) technology which allows you to automatically tag the location where you took your photos. You can later categorize, organize, and search for photos based on location. This is very useful for travel and outdoor photographers for documenting the locations where images were captured.
  Check out the cameras in our database that have built-in GPS.

Built-in Wi-Fi on Sony Alpha SLT-A99 II

Sony Alpha SLT-A99 II has a built-in Wi-Fi (802.11b/g/n, 2.4 GHz) which allows to easily transfer photos and videos from the camera to other Wi-Fi-enabled devices, such as smartphones, tablets, printers, or computers. This eliminates the need for cables and allows for quick and convenient media sharing and social media integration. It gives you the ability to control your camera remotely using a smartphone or tablet. This is particularly useful for taking self-portraits, group shots, or capturing images in challenging conditions without having to touch the camera. Firmware updates can also be downloaded and installed wirelessly.
  Check out the cameras in our database that have built-in WiFi.

Bluetooth on Sony Alpha SLT-A99 II

Sony Alpha SLT-A99 II has a built-in Bluetooth (version 4.1) which lets you to connect the camera to a smartphone or a dedicated remote control device. This allows you to remotely trigger the camera, adjust settings and controls remotely through a paired mobile app. While Wi-Fi is generally faster for transferring larger files, Bluetooth can be used for small, selective transfers, it can provide real-time information about your camera's battery status, memory card capacity, and other key settings directly on your paired smartphone or smartwatch.
  Check out the cameras in our database that have built-in Bluetooth.

NFC on Sony Alpha SLT-A99 II

Sony Alpha SLT-A99 II has Near Field Communication (NFC) technology which simplifies the process of pairing it with other NFC-enabled devices like smartphones or tablets. It allows to quickly transfer photos and videos or remotely control the camera from compatible device. NFC can also be used for authentication and security purposes. It can verify your identity before accessing certain features or transferring sensitive data. It can be used with NFC-enabled accessories as well, such as lenses, flashes and GPS devices.

USB Inputs and HDMI Outputs

Both models have USB 2.0 (480 Mbit/sec) inputs for data transfer. Sony Alpha SLT-A99 II has a Micro HDMI and Sony Alpha SLT-A55 has a Mini Type C HDMI connector for video signal output.

Battery

Sony Alpha SLT-A99 II comes with NP-FM500H battery pack with battery life of 490 shots and Sony Alpha SLT-A55 comes with NP-FW50 battery pack with battery life of 380 shots.

External Storage Slots

Sony Alpha SLT-A99 II has two card slots - one for SD/SDHC/SDXC (UHS-II) and one for SD/SDHC/SDXC/Memory Stick Duo Hybrid (UHS-I). Sony Alpha SLT-A55 has a single SD/SDHC/SDXC, Memory Stick Duo/Pro Duo/Pro-HG Duo card slot.

Shutter

Sony Alpha SLT-A55 has Electronically controlled Vertical-traverse Focal-plane shutter. Shutter speed can go up to 1/8000 sec on Sony Alpha SLT-A99 II, and up to 1/4000 sec on Sony Alpha SLT-A55. Sony Alpha SLT-A99 II can shoot continuously up to 12.0 fps. Sony Alpha SLT-A55 can shoot continuously up to 10.0 fps.

Focusing

Sony Alpha SLT-A99 II has TTL Phase-detection AF system with 399 (15 cross-type) focusing points and Sony Alpha SLT-A55 has 15 (3 cross-type) focusing points. Sony Alpha SLT-A99 II has detection range from -4 to +18 EV.

Exposure

Exposure meterings of Sony Alpha SLT-A99 II ranges from -2 to +17 EV and you can set the exposure compensation within the ±5 EV range on Sony Alpha SLT-A99 II and ±2 EV range on Sony Alpha SLT-A55. You can also do exposure lock, exposure bracketing and manual exposure adjustment on Sony Alpha SLT-A99 II and exposure lock, exposure bracketing and manual exposure adjustment on Sony Alpha SLT-A55.

Flash

Sony Alpha SLT-A55 has a built-in flash with maximum range of 10.00 m (@ ISO 100) and also accepts external flash. Sony Alpha SLT-A99 II has no built-in flash but an external flash may be connected via Hot Shoe or Proprietary. The fastest flash synchronization speed is 1/250 sec on Sony Alpha SLT-A99 II and 1/160 sec on Sony Alpha SLT-A55.

Sony Alpha SLT-A99 II body has dimensions of 143 x 104 x 76 mm (5.63 x 4.09 x 2.99") and Sony Alpha SLT-A55 body has dimensions of 124 x 92 x 85 mm (4.88 x 3.62 x 3.35"). Sony Alpha SLT-A99 II weighs 849 g (1.87 lb / 29.95 oz) and Sony Alpha SLT-A55 weighs 500 g (1.10 lb / 17.64 oz).

Sony Alpha SLT-A99 II

Sony Alpha SLT-A55

143 mm

104 mm

124 mm

92 mm

104 mm

92 mm

76 mm

85 mm