The Ikegami UHL-X40 Ultra-Compact UHD HDR Camera by Gisbert Hochguertel, Ikegami Europe

Introduced at the October 2024 NAB New York exhibition, the Ikegami UHL-X40 is a broadcast-quality box-style UHD/HD HDR camera designed for applications where size and weight are a major concern. Examples include robotic studio, remote sport and stage production, and point-of-view video capture. The UHL-X40 is based on the UHL-F4000 camera which has achieved great success in aerial applications such as gimbal-mounted imaging from helicopters.

The UHL-X40 itself is an ultra-compact head measuring 120 x 128 x 89 mm, weighing 1.1 kg and consuming 28 watts of 12 volt DC power. Its light weight allows the use of a space-efficient pan/tilt mount. Signal processing is performed in a separate unit, the CCU-X40, which measures 145 x 145 x 173 mm, weighs 2.6 kg. Both units are shown in Figure 1. The CCU-X40 consumes just 82 watts of power, also at 12 volts DC, and provides a wide variety of signal outputs. Also shown is an optional tally box which can be connected and attached to the camera head. The CCU-X40 includes all necessary connections to traditional broadcast infrastructure.

The UHL-X40 camera head connect with the CCU-X40 via up to 10 km of duplex single-mode fibre (Figure 2) carrying native RGB raw pixel data. Or a bi-directional core with an optical circulator can be used. Included with the fibre link is a 1G Ethernet trunk for external data such as pan/tilt/zoom control. The camera incorporates three full broadcast quality 2/3-inch UHD HDR sensors with a global shutter pixel architecture. These are similar to the sensors and architecture used in latest-generation Ikegami UNICAM XE cameras such as the UHK-X700 and UHK X600. They capture natural images even when shooting LED screens, clear of geometric distortion during still frame replay. This avoids artifacts commonly experienced when using rolling shutter sensors: bending of horizontal lines and flash-band effects when televising flash/strobe-illuminated stage environments. The UHL-X40 has a high sensitivity of F11 (at 2160/50P) at a signal-to-noise ratio of 62 dB. Its B4 mount ensures compatibility with the majority of broadcast TV lenses.

Optical filter system

The UHL-X40 camera head is equipped with a similar optical filter system to the one employed in Ikegami UNICAM-XE cameras. Two integrated optical filter wheels allow separate control of colour temperature and incoming light. Four neutral-density filters allow individually control of the incoming light level in 2 F-stop steps.

The colour correction filter wheel incorporates optical filters for 3200K, 4300K and 6300K colour temperatures. A cross filter is also included plus a free space to mount any desired type of filter such as an additional optical low-pass filter to control aliasing more effectively.

The three-sensor design of the UHL-X40 gives full resolution to each of the RGB channels . It also eliminates coloured edges on moiré and aliasing figures, an inherent problem when using cameras that have a single sensor with a Bayer pattern for colour separation.

High Dynamic Range

The UHL-X40 camera fully supports HLG (Hybrid Log Gamma) conforming to ITU-R BT.2100, the international standard for high dynamic range (Figure 3). PQ and S-Log gamma curves can be installed on request. For high quality HDR capture, the UHL-X40 is equipped with a servo-controlled, five-position colour correction filter wheel. As such, individual control of the colour temperature is possible by using an optical filter (for 3200K, 4300K and 6300K). Compared with electronic colour temperature correction techniques such as increasing the gain of the blue channel to obtain exact colour reproduction under daylight conditions, the use of optical filters give a huge advantage for HDR productions, especially in daylight conditions.

Optical vignetting correction

The UHL-X40 includes automatic vignetting correction and F stop ramping compensation for the zoom lens (Figure 4), minimising dark corners and overall loss of light when the lens is in telephoto position and/or the iris is wide open. The majority of currently available broadcast lenses support this function and as such communicate with the camera informing the individual ramping and vignetting data when connected via the digital lens interface.

Digital zoom

The UHL-X40 features a digital zoom function enabling up to 10.0x enlargement in increments of 1.1 steps. Very smooth, natural and wide-ratio zoom is achievable when optical and digital zoom are combined. Another advantage is that there is no loss in sensitivity when operating the digital zoom function whereas the 2x range lens extender reduces the sensitivity by 2 F-stops.

HD cut out

The CCU-X40’s simultaneous HD output can be either a downconversion of the entire viewing angle of the UHD image or a 1920 x 1080 HD window (taken from the UHD image center. When performing HD cut out, the CCU-X40 feeds two images with different viewing angles simultaneously (Figure 5).

Focus-assist and remote back-focus

Focus Assist Function is achieved by placing the edge components of the 4K image on the HD monitor output feed, allowing critically focus of 4K images using an HD monitor. Back-focus of supported lenses can be performed remotely using an OCP-300 or OCP-500 operation control panel (Figure 6) in conjunction with a picture monitor fed directly from the CCU-X40.

Image reversal

The UHL-X40 can output an upside down reversed image for applications such as ceiling mounting (Figure 7). No external image flip effect function is necessary, saving inputs on a vision mixer.

Automatic video level control

The AVC (Auto Video-Level Control) function allows the camera to maintain a constant video level by automatically controlling the neutral-density filter position, iris, gain and shutter speed. AVC function limits can be set individually via the camera menu.

Auto tracking white balance

The UHL-X40 features ATW (Auto Tracking White Balance) in addition to a one-push AWB function. The ATW function makes it possible to adjust white balance continuously when shooting at varying colour temperatures.

Ethernet trunk line

An Ethernet trunk line is available between the camera head and CCU as a standard feature. Using this line enables a distant CCU operator to send commands to a peripheral device such as a pan/tilt head or a teleprompter.

Remote control

Like all other Ikegami system cameras, the UHL-X40 can be controlled using an RM-71F, OCP-100, OCP-300 or OCP-500 panel as well as using MCP-300 and the corresponding virtual control panels. The UHL-X40 /CCU-X40 can be connected to the various Ikegami control panels by using the conventional ICCP-control or the very commonly used Ethernet-based control system. Customers can flexibly select the desired control system according to their individual needs. The OCP-300 and OCP-500 feature PoE+ (Power over Ethernet) so an additional power supply unit is not necessary. The OCP-100 and compact RM-71F can only be connected to the UHL-X40/CCU-X40 by ICCP-control using a dedicated CP-cable.

Summary

The UHL-X40 is a robust and versatile camera designed for easy integration into a wide range of broadcast-related production environments. Combining full broadcast quality 3-CMOS imaging and advanced digital processing with compact dimensions, light weight and versatile remote connectivity, it is ideal for use in robotic pan/tilt/zoom applications such as studio stages, newsrooms, sports stadiums or point-of-view video capture. With its three new global shutter UHD CMOS sensors and ASIC, the UHL-X40 fits perfectly into the Ikegami UNICAM XE broadcast camera range and assures a unique high end viewing experience.