Figure 1, a simulated comparison of standard dynamic range image (SDR) image versus a high dynamic range (HDR) image.
If you’ve purchased or researched a new TV for your home or church in recent years, you have undoubtibly heard of High Dynamic Range (HDR), and how it enables displays to better reproduce what our eyes see in real life. But while most HDR discussion in the consumer electronics market focuses on home theatre applications and which distribution platforms can bring HDR into the home today, the technology also offers a significant opportunity for houses of worship to enhance their IMAG. A fully HDR-enabled workflow can help those at the back of your sanctuary more accurately experience the visual splendor of your worship services and live performances as if they held a front row seat – and can even be done without the additional infrastructure expense of 4K Ultra HD.
A fully HDR-enabled workflow can help those at the back of your sanctuary more accurately experience the visual splendor of your worship services.
What is HDR?
“Dynamic range” refers to the difference between the blackest black and brightest white that can be seen on a video display. High Dynamic Range (HDR) is a significant step forward in improving the images that viewers see on televisions and other displays, dramatically extending the range from very dark to highlights while adding detail in the mid-tones and shadows of the picture.
More than just “brighter pictures”, HDR allows us to see more detail in the darker and peak bright areas of the picture, more closely matching what the human eye sees in real life. HDR also provides increased contrast, which gives the appearance of sharper pictures with more saturated colors.
See Figure 1: A simulated comparison of an SDR (left) and HDR (right) picture.
In the simulated pictures above, the sky in the left SDR image is overexposed and there is little detail or color in that region. The red circle shows a missing TV antenna that we can see in the HDR picture along with the detail in the clouds. This gives the image a much different feeling than the flat, blown-out sky on the left. In the SDR version, some detail is also lost in shadows under the trees along the street. The actual HDR picture would be about 10 times brighter in the sky and peak highlights. HDR produces superior highlight handling and improved detail in mid-tones, while the greater contrast produces a sharper subjective picture and more saturated color, as seen in the blue parking sign.
HDR in Houses of Worship
HDR is particularly well-suited to being used in houses of worship. Many church productions are extremely visually rich and incorporate both subtle and dynamic lighting effects, which require a wide exposure latitude to fully capture them on video. HDR allows producers to more accurately capture and reproduce the nuances of the performances and lighting, both for IMAG and other forms of distribution.
A common misconception is that HDR is directly connected to Ultra HD and 4K.
The benefits of HDR can only be realized with a combination of HDR acquisition and HDR-capable displays. This is where houses of worship have an advantage over many television broadcasters who will not able to deliver HDR until further adoption of ATSC 3.0, and most broadcast audiences still have Standard Dynamic Range (SDR) TVs. In contrast (no pun intended), churches control both the cameras and the display devices they use for in-venue viewing.
As such, HDR can be used by churches today and would immediately yield greatly improved pictures. While most projectors may not be able to display as high a brightness as a new flat panel display in a living room, church sanctuaries often have relatively low ambient lighting, making the brightness of the projector sufficient for audiences to benefit from the advantages of HDR over SDR.
It’s important to note that there are multiple specifications under the HDR umbrella that are designed to accomplish similar things. For live applications such as IMAG, one of the most important HDR profiles is Hybrid Log Gamma (HLG) which was developed for live TV, while others include SMPTE ST 2084 (also known as PQ), which is compatible with the HDR10 open standard for consumer TVs. Most church tech directors won’t need to know the inner workings of each standard, but it’s important to be sure that your cameras, displays and everything in between are all compatible with the same HDR variant.
Not Just 4K
A common misconception is that HDR is directly connected to Ultra HD and 4K. This likely stems from the state of the consumer television market; if you want to buy a new TV with HDR today, it will also be a 4K/UHD TV. In fact, HDR is independent of the picture resolution and improves HD video just like it does 4K or 8K – and can actually make a more obvious difference to the visual experience than a higher resolution can. While UHD delivers more pixels, HDR provides ‘better’ pixels – as above, more detail, expanded mid-tones, brighter highlights and more saturated colors.
HDR is particularly well-suited to being used in houses of worship.
For church IMAG, at the distances your audience will be sitting from the screen, HDR will have more of an impact than 4K for most viewers. Of course, if you can afford to implement both 4K and HDR, you can have the best of both worlds. But “bits are bucks”, and moving to 4K comes with higher infrastructure, processing overhead, storage and bandwidth requirements – thus making the combination of HD and HDR a more cost-effective choice for many churches.
Hitachi Kokusai and HDR
Hitachi Kokusai was one of the first manufacturers to deliver HDR-capable broadcast television cameras. We continue to be active in making HDR more understandable and cost-accessible to customers like churches through educational sessions and by including it as a standard, no-cost feature for all our MOS and CMOS cameras. These cameras support HDR variants including the afore-mentioned HLG and HPQ, with our current models capable of up to 15 F-stops of exposure.
Of course, many churches are acquiring video for more than just IMAG, and while they control their in-venue displays, they may also need to distribute SDR video for wider reach such as online viewing. Through advanced functionality in the camera control units (CCUs), Hitachi camera systems can output both HDR and SDR simultaneously with individual adjustments to optimize each picture.
Hitachi Z-HD5500 and SK-HD1800 cameras feature global shutter technology that can greatly reduce or eliminate flickering on LED walls, while delivering the impressive, lifelike video that HDR offers.
Hitachi cameras are ideal for churches for more than just their HDR capabilities. They have long been favorites of churches because of their high performance and cost-effectiveness, and recent sensor technology advances have reinforced our camera systems as the preferred choice. Lower-cost LED screens and lighting are becoming more commonplace in houses of worship, but may cause image artifacts such as flickering when captured via camera. Our Z-HD5500 and SK-HD1800 cameras feature global shutter technology that can greatly reduce or eliminate these issues, while delivering the impressive, lifelike video that HDR offers.
