Lens & Scene: The True Engines of Dynamic Range

The Limits of Dynamic Range: Why Real Scenes Beat Test Charts

High dynamic range (HDR) capture is often reduced to a sensor spec. Standard test charts claim to measure DR but fail to assess real-world performance. True dynamic range hinges on two factors charts ignore: how light is arranged in the scene and the lens capturing it.  

A 2024 study confirms this. Dynamic range acquisition relies on, in order of importance:

1. The spatial distribution of light in the scene, 
2. The lens, 
3. The sensor. 

Glare—stray light scattering within the lens—is the primary constraint, reducing usable dynamic range by 48% on average [1]. No chart provides absolute measurements because results vary according to layout and patch sizes. As the researchers state: 

“The effect of glare and spatial distribution […] is massive, systematic and unavoidable.” 

The Brutal Takeaway

Test charts aren’t just optimistic—they’re disconnected from reality. They disregard glare (a lens flaw), ignore spatial relationships (a scene characteristic), and misleadingly treat the sensor as the sole variable. 

Spatial Contrast: HDR’s Secret Weapon

This revelation intersects with a deeper truth: HDR’s power lies not in extreme brightness, but in preserving spatial contrast relationships that SDR compresses—how adjacent highlights and shadows interact. To leverage this: 

• Place bright elements (windows, lamps) against deep shadows. 
• A 500-nit highlight alongside a 0.01-nit shadow creates a stronger impression than 1,000 nits floating in a middle gray void.  

This technique creates a worst-case scenario for cameras: high contrast scenes maximize veiling glare, directly challenging shadow preservation near bright areas. Ironically, what serves the story best also pushes the technology hardest.

A New Workflow for Filmmakers

To leverage this for storytelling while stress-testing gear:  

1. Test lenses, not sensors: Prioritize flare-resistant optics (multi-coated primes). Evaluate against backlit windows—not charts.
2. Expose for highlight retention: Preserve critical highlights. Let shadows fall naturally—avoid artificial lifting in post.
3. Design for adjacency: Block shots where light and dark collide.
4. Review for haze: Check footage for washed-out shadows near bright areas.

“Lens design software optimizes resolution, but flare resistance demands material science (coatings) and mechanical precision (baffling). Newer brands lack the decades of R&D held by industry leaders.”

The Holistic Shift

HDR is an end-to-end workflow—from lens selection to final grade. This paradigm shift rejects SDR’s compartmentalized approach. By controlling glare, you preserve spatial contrast—HDR’s core strength. 

1. McCann et al. showed that glare reduces the effective dynamic range (DR) in cameras by at least three orders of magnitude. McCann, J.J., Rizzi, A.: Camera and visual veiling glare in hdr images. J. Soc. Inform. Display 15(9), 721–730 (2007)