Edited and prepared by Oscar Michel, Masters in Journalism, DCU.
Insights on the LUMIX DC-GH5 by Panasonic Key Technologies
The LUMIX DC-GH5 is the flagship model for Panasonic Digital Single Lens Mirrorless Cameras. Since its March 2017 launch, it has doubled the performance of its predecessor, the GH4, which became a major hit with the world’s first 4K video recording as a digital single lens mirrorless camera. The points to take note of are the high-performance 4K video function for use on professional locations, and the 6K PHOTO function. The main issue was the heating problem.
— Panasonic Corp. (@panasonic) July 24, 2017
Faced with a Heat Problem for Unlimited Video Recording and Ultrahigh Motion Picture Quality
The GH5 achieved the world’s first 60p/50p video recording and the world’s first 4:2:2 10-bit 4K 30p/25p video recording while also enabling unlimited video recording. However, heat inside the camera body became a large problem for these achievements. The amount of video data necessary for the GH5’s ultrahigh picture quality is more than 3 times that of the GH4. As data increases, the power consumption also rises and the temperature inside the camera greatly increases. It would be easy to disperse the heat by increasing the size of the camera body, but we insisted on maintaining the size and grip that were so popular with the GH4. As a result, GH5 development became a “Battle with Heat.”
Gaining Power-Saving Efficiency and Heat Dispersion by Optimising Panasonic Strengths
Suppressing the Heat Generation Itself
We focused on the fact that the image processing section consumes the most power in a digital camera. As such, we worked on ways to save power in LUMIX’s original image processor, the Venus Engine. We noted the differences in resolution, noise, and frame rate between still pictures and motion pictures, and then isolated and optimized the motion picture processing section of the newly developed Venus Engine. We reduced the circuit scale that operated during video recording by half.
We then revised the power supply efficiency for the circuits common to still and motion pictures. These were originally designed to be optimum when recording still pictures, so the power supply efficiency dropped when recording motion pictures. This was a cause of heating. While preserving efficiency during still picture recording, we switched to a concept of raising the power supply efficiency when recording motion pictures. By achieving improvements step by step, such as careful component selection and adjustment of the wiring width and length, we were able to improve power supply efficiency by 10% or more during 4K 60p/50p video recording.
Efficiently Dispersing the Generated Heat
As part of our efforts to disperse heat, we also provided heat dispersion paths on the bottom surface of the circuit board for the image processing engine. Conventionally, a bypass capacitor is positioned on the bottom surface of the circuit board to stabilize the power supply voltage. On the newly developed Venus Engine, the capacitor position was adjusted by applying a heat-dispersion sheet, which succeeded in a 12% improvement in heat capacity.
When heat dispersion is correctly done, the temperature distribution for the surface of the camera body is nearly uniform. Pursuing this “uniform heat” in order to eliminate the minor differences through heat simulation, we finely tuned the design by repeatedly testing with actual cameras. As a result, even with continued use at 40ºC, all devices were able to operate without exceeding the rated temperature, and the camera’s surface maintained a uniform temperature.
Panasonic beat the heat problem with in-house development of both the camera and the LSI. By making improvements step by step, we were able to achieve a body size of 1.13 times that of the GH4, while trial calculations were 1.35 times. Even so, features include a Body Image Stabilizer, double SD Memory Card slot, HDMI Type A terminal, and 3.2-inch rear monitor.