Pro video blog…Produced by Philip Johnston DoP/Editor

This is a very interesting photograph taken at the H Preston Open Day at Hampton on Tuesday the 7th of December 2010, it shows a simple shot of various customers watching a demonstration of the Panasonic AF101 but it also reveals in stunning detail the quality of the picture coming off the LCD television via the AF101.

The camera has a prime lens fitted which will certainly produce sharp shots but it’s also a testimony that this camera produces a very sharp, punchy picture with one 500W LED light reflected off a back wall, the general consensus on the open day was the AF101 produced a great picture.

I have some more information from Panasonic about the AF101 it reads as follows…

Through 24p recording on the AG-DVX100, variable frame rate recording with the Varicams and AG- HVX201, Panasonic has continually been the first to provide new technologies for professional video creation.

A 4/3 type image sensor, originally developed for use in digital still cameras is used in the AG-AF101 to record video. This camera represents the next generation of video cameras, and through the use of a large image sensor and interchangeable lenses, will greatly expand the creative options available to each user.

A newly developed 4/3 type MOS Image sensor is used in this camera. Normally, the aspect ratio for still images is 4:3 or 3:2 (some cameras are 1:1), while the aspect ratio for HD video is 16:9. In the case of the AG-AF101, the 16:9 aspect effective video area is positioned on the image sensor surface, and the total effective number of pixels on the image sensor is 12.4 million.

The size of a 4/3 type sensor is defined as 17.3mm x 13mm, similar to the size of 35mm film (22mm x 16mm). The 2/3 type sensors commonly used in high-end video cameras measure 8.8mm x 6.6mm, making 4/3 type sensors about four times larger than 2/3 type sensors. A large sensor allows for achievement of shallow depth of field, increasing creative choices for the shooter, as well as the possibility to use brighter lenses.

There are even larger sensors, such as those used on 35mm still cameras (full frame), but these however cause numerous problems when shooting video: 1. Since the sensors are developed primarily for still photo use, they have a very high

pixel count (ex. 20 million), and when in video mode, must process sixty images per second. This leads to an increase in the operating frequency, and makes it necessary to either reduce the recorded frames per second or record for short periods only to avoid internal overheating.

2. For shooters used to working with 35mm film, the depth of field when shooting with 35mm still (full frame) cameras is too shallow, resulting in the blur being too strong.

3. Prime and Master Prime lenses designed for 35mm or Super35 film do not cover the full image area of a 35mm still image (full frame).

4/3 type image sensors do not carry any of the above problems, and because the flange back (the distance between the lens mount and sensor) is short, allowing for the use of nearly any available lens (details later in this document.).

On the AG-AF101, a 17.8mm x 10mm 16:9 section is used from the 4/3 type sensor to create an HD signal. The actual sensor is slightly larger than the four thirds standard of 17.3mm x 13mm, which is used to its full extent for the most possible effective pixels. There are many applications and websites available that will reproduce the angle of view and depth of field when the effective sensor size and lens characteristics are entered.

Tomorrow we are going to look at the Panasonic micro 4/3″ mount itself as there is still some confusion about what fits straight onto the camcorder.


Having been working in the video business since 1988 I have amassed a great amount of knowledge of both the kit and production values over the last 30 years.

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