Feature Articles

Sony's Alpha Strike: Designing the A700

Sony's Alpha Strike: Designing the A700

On the Alpha A700's Features and Design Considerations

On the Alpha A700's Features and Design Considerations

HWZ: If you could highlight one strong feature of the A700, what would it be and why?

Ishizuka: The number one feature in the A700 is its picture quality. We have developed a new EXMOR CMOS image sensor with a resolution of 12.24MP. The main feature of this sensor is its low noise technology. We've implemented the A/D converter inside the sensor which makes this a very fast sensor. We have dramatically reduced noise, especially in the high ISO range. In addition, we've also developed a new BIONZ image processor which reproduces high quality pictures in high speed. Based on these two technologies, we've realized high quality with low noise. This is the number one feature on the A700.

The next thing we took into consideration is the enjoyment of a picture after it has been taken by the camera. In this field, we have strength and uniqueness because we have experience in our product lineup with the Bravia and VAIO. This product has a new feature called Photo TV HD. The A700 also has a built in HDMI terminal so we can connect the camera to the TV directly. The camera and our TV will synchronize to reproduce the best quality of still image. This is the new trend; Showing large images on a high-definition TV.

Our BIONZ processor has also been newly developed with a new engine for this camera. We've developed new features to meet the requirements of the new EXMOR CMOS sensor.

HWZ: What were some of the considerations you had to make when starting to design the A700?

Ishizuka: This is our mid-ranged DSLR offering. Generally in this class of product, we prioritize balancing the strength of the body with a wealth of functions. Weight is a consideration but we don't concentrate too much on that. We did however set up a target weight of less than 700g while keeping the product strength and features in tact in the body. Our aim with this camera is to allow it to be carried around easily by the average photographer. This was the reason the Alpha 700 was named as such.

Our next consideration is the way the shutter sounds. Our engineers aimed to develop a product with a pleasing shutter sound. We put in a good deal of effort in developing the way the shutter sounds. Although the actual effect of the shutter sound on a person's feelings is difficult to analyze, this proved to be one of the biggest problems. The solution to this problem lay in a co-development with our camera engineers and audio engineers. This is one of the assets of Sony. The approach of a camera engineer and an audio engineer are completely different in analyzing the situation of what makes a comfortable sound. Through our customer feedback, we've discovered that the way the shutter sounds is an important factor for long term comfort. That's why we insisted on improving the shutter sound.

HWZ: What was the main motivator for the switch from a CCD sensor on the A100 to a CMOS one in the A700?

Ishizuka: Our main reason was how to maintain high speeds with low noise. We have compared solutions from both the CCD and CMOS technology. Finally, due to the advantage of speed and low noise we decide to choose a CMOS sensor. Our product has a 12MP resolution which is higher than the A100's 10MP.

Another reason was the operating temperature of the CMOS sensor, especially after continuous shooting. Sometimes, CCD image sensors can get a little high in temperature. The CMOS sensor has the advantage of a temperature curve. We found that speed and picture quality was kept in good balance using a CMOS sensor.

HWZ: Tell us more about the Exmor CMOS sensor and the Bionz processor. How do these innovations for the Alpha compare when put up against your competitors?

Ishizuka: Normally, an A/D converter is placed outside on a separate circuit. We've placed the A/D converter inside the sensor. The construction of the CMOS sensor is like this. On the front, there are many silicon cells. We then place 4000 A/D converters on the back side of the cell. Between the A/D converter and the front sensor, we've also added a noise reduction layer inside the chip. This is a revolutionary technology. Even before a signal leaves a chip, we have already minimized noise levels.

If you buy an A/D converter from Akihabara in Tokyo, it will cost around 50 Japanese Yen (S$0.63). The A700's sensor has 4000 of these in its sensor.

Normally noise reduction is applied to an image after the Analogue to Digital conversion. This is the general process. However, our strength is our application of noise reduction in the Analogue process. In the analogue state especially, the outside environment negatively influences noise levels therefore the most effective way to reduce noise is to ensure proper noise reduction of the analogue signal. Therefore we placed the noise reduction circuit inside the sensor. This is why we can reduce noise so well.

The advantage that Sony has is that we can get the latest sensor manufactured faster. An advantage of this in the future is that we can produce image sensors which best fit our DSLRs. We can introduce so many future technologies inside future image sensors. This is an advantage that Sony has for the development of the CMOS sensor.


HWZ: Tell us more about the Memory Recall (MR) function.

Ishizuka: The memory recall function allows us to keep our favorite settings and recall them quickly to avoid many settings changes. We can tweak the settings through the menu. There are allowances for three different sets of settings. If we want to keep a current setting, you merely rotate the dial to the MR position and easily select one of the three custom settings.

For example, if I generally take landscapes but occasionally take portraits, it's easier to change between Portrait and Landscape scene modes or single shot and burst mode. Normally, we need to change a variety of picture setting for different situation and this takes time. In this case, if we use Memory Recall, a simple switch between modes will suffice. MR allows for the memorization of over 20 settings.

HWZ: The new vertical grip seems made for the photographer in mind, with every button strategically placed for easy access. With this new development, will future Alpha products undergo the same treatment?

Ishizuka: Our philosophy for design the vertical grip was to retain the same holding position and operation as when the camera is used horizontally with special attention to the shutter release button which is more natural than on other cameras. Competing products usually have the shutter button in a much higher position when used vertically. Our priority was to have a design that was easier to hold. This will be something we will be bringing forward on our future high-end product lines.