HMG-4 is a minus-green (magenta-balance) filter that trims the yellow-green band to clean up LED/fluorescent casts while keeping healthy blue and strong long-red. Transmission starts around ~64–66% at ~390–410 nm, crests near ~75–78% around ~455–470 nm, dips through green to ~62–64% around ~540–550 nm, then rises to ~88–91% around ~650–665 nm before tapering toward ~50% by ~780 nm.
Key advantages
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Remove green cast — controlled reduction across ~520–570 nm neutralizes “plus-green” from LEDs and discharge sources without pushing magenta too far.
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Keep red richness — high throughput (~88–91% T) around ~650–665 nm preserves skin warmth, woods, food, and textiles.
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Balanced blue — ~75–78% T near ~455–470 nm maintains crisp whites and cyan detail.
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Smooth, low-ripple curve — gently shaped response avoids banding and keeps corrections predictable across fixtures and dim levels.
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Production-ready durability — hard dielectric stack resists abrasion and humidity; optional rear-surface AR and slight wedge suppress ghosts and flare.
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Custom formats — Borofloat®, Eagle XG, or D263 T (0.21–3.8 mm) for high-temp use to ~450 °C; soda-lime for ≤150 °C. Custom sizes 5–450 mm.
Typical applications
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Cinema/TV lighting — lift TLCI/CRI by pulling excess green while keeping natural reds and blues.
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Photography & events — cleaner skin tones and neutral whites under mixed LED/fluorescent rigs.
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Retail, museum & hospitality — corrects greenish ambience to present true product and artwork colour.
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Architectural & display — tune off-the-shelf luminaires for warmer, premium colour.
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Machine vision — reduce green flare to stabilize channels for red-dominant features.
Need test chips tomorrow or thousands next quarter? HMG-4 filters are coated and cut-to-size (including dicing) to your exact spec—fast.
