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Glistenis 20° Downlight Lens - 30mm Diameter

£399
RRP £480
The RRP is the manufacturer's recommended retail price of the item.
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Description

The Glistenis is a 30mm diameter glass lens that narrows the beam angle of compatible downlight fittings to 20°, creating a tightly focused spot of light. The lens sits in the downlight aperture and uses optical refraction to concentrate the light output into a narrower cone than the fitting's standard beam angle, which typically ranges between 40° and 60° depending on the fixture.

Designed for accent lighting, the 20° beam angle suits applications where concentrated light is needed on a specific object or surface: artwork in galleries, retail display shelving, architectural details, feature walls, or worktop task zones in kitchens. The narrower beam reduces spill light into surrounding areas, creating higher contrast between lit and unlit zones and giving more control over where light falls in a room.

The 30mm diameter fits the majority of recessed downlight housings that accept interchangeable lenses or reflectors. The glass construction maintains optical clarity over time without the yellowing or clouding that can affect lower-grade polycarbonate lenses. Installation involves placing the lens into the downlight holder before or after fitting the bulb, depending on the specific downlight model. The lens works with LED, halogen and filament bulbs, though beam modification is most effective with directional LED sources.

Specification
Diameter (mm) 30
Warranty 5 Years
Frequently Asked

Which downlights is this lens compatible with?

The 30mm diameter fits most recessed downlight fittings designed to accept interchangeable lenses or optical accessories. Check your downlight's specifications or measure the lens holder diameter before ordering. Ideal Lux Glistenis downlights are designed to pair with this lens directly.

What's the difference between 20° and wider beam angles?

A 20° beam creates a tightly focused spot of light, concentrating output onto a smaller area with higher intensity. Standard downlights typically offer 40-60° beams, which spread light more evenly across a room. The 20° lens is for accent lighting rather than general ambient illumination.

Does the lens reduce light output?

The lens redirects and focuses the light rather than blocking it, so total lumen output remains similar. However, because the light is concentrated into a smaller area, the perceived brightness (lux) at the centre of the beam increases, while light outside the 20° cone is reduced.

Can it be used with LED bulbs?

Yes. The lens works with LED, halogen and filament sources. Directional LED bulbs (those with reflectors or lenses already built in) give the most predictable beam modification. Omni-directional LED bulbs may produce some secondary spill light around the lens edge.

Shipping & Returns

Delivery UK delivery is £14.99, and delivery is free on all orders of £99 or more, in the UK and internationally.

Returns If you change your mind, you have 14 days from delivery to tell us, and a further 14 days to send the goods back. Return postage for a change-of-mind return is paid by you. Change-of-mind returns are subject to an inspection and handling deduction. See our full returns policy.

To arrange a return, call us on 020 8149 5199 or use our contact page.

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Free delivery on orders over £99, in the UK and worldwide. Easy returns within 14 days, subject to our returns policy. Full manufacturer warranty included.

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    Description

    The Glistenis is a 30mm diameter glass lens that narrows the beam angle of compatible downlight fittings to 20°, creating a tightly focused spot of light. The lens sits in the downlight aperture and uses optical refraction to concentrate the light output into a narrower cone than the fitting's standard beam angle, which typically ranges between 40° and 60° depending on the fixture.

    Designed for accent lighting, the 20° beam angle suits applications where concentrated light is needed on a specific object or surface: artwork in galleries, retail display shelving, architectural details, feature walls, or worktop task zones in kitchens. The narrower beam reduces spill light into surrounding areas, creating higher contrast between lit and unlit zones and giving more control over where light falls in a room.

    The 30mm diameter fits the majority of recessed downlight housings that accept interchangeable lenses or reflectors. The glass construction maintains optical clarity over time without the yellowing or clouding that can affect lower-grade polycarbonate lenses. Installation involves placing the lens into the downlight holder before or after fitting the bulb, depending on the specific downlight model. The lens works with LED, halogen and filament bulbs, though beam modification is most effective with directional LED sources.

    Specification
    Diameter (mm) 30
    Warranty 5 Years
    Frequently Asked

    Which downlights is this lens compatible with?

    The 30mm diameter fits most recessed downlight fittings designed to accept interchangeable lenses or optical accessories. Check your downlight's specifications or measure the lens holder diameter before ordering. Ideal Lux Glistenis downlights are designed to pair with this lens directly.

    What's the difference between 20° and wider beam angles?

    A 20° beam creates a tightly focused spot of light, concentrating output onto a smaller area with higher intensity. Standard downlights typically offer 40-60° beams, which spread light more evenly across a room. The 20° lens is for accent lighting rather than general ambient illumination.

    Does the lens reduce light output?

    The lens redirects and focuses the light rather than blocking it, so total lumen output remains similar. However, because the light is concentrated into a smaller area, the perceived brightness (lux) at the centre of the beam increases, while light outside the 20° cone is reduced.

    Can it be used with LED bulbs?

    Yes. The lens works with LED, halogen and filament sources. Directional LED bulbs (those with reflectors or lenses already built in) give the most predictable beam modification. Omni-directional LED bulbs may produce some secondary spill light around the lens edge.

    Shipping & Returns

    Delivery UK delivery is £14.99, and delivery is free on all orders of £99 or more, in the UK and internationally.

    Returns If you change your mind, you have 14 days from delivery to tell us, and a further 14 days to send the goods back. Return postage for a change-of-mind return is paid by you. Change-of-mind returns are subject to an inspection and handling deduction. See our full returns policy.

    To arrange a return, call us on 020 8149 5199 or use our contact page.