Main lighting methods for enhancing volume of jewellery items

Main lighting methods for enhancing volume of jewellery items in display cabinets. People's attention gets drawn to the best lit things. When both thermal temperature and brightness of the general lighting at a store match the lighting in this store's display units, the customer's eye will have nothing to get focused on. Every aspect here has its own significance, from the general lighting and display-cabinet lighting to the accent lights for the jewellery items themselves. It is well known that in the absence of an appropriate lighting, the items on display will lose most of their visual appeal and, therefore, will be harder to sell.

The lighting methods for enhancing volume of a large jewellery piece arrive into the world of jewellery lighting from the traditional concepts of the three point lighting arrangement. Typically, this method of arranging lights ensures high-quality results.

The most famous lighting method is known as "three point lighting". In fact, this set-up can involve even four or more light sources. That's because in such a setup the fill light is not directed onto the jewellery item, therefore it is not counted in the setup name.

Main light characteristics

Colour temperature.

A lamp hue is closely linked with a colour temperature, which means that at a high colour temperature the lamp light will produce a cooler hue.  Warm coloured objects should be illuminated with the warm-light lamps, and cool coloured objects should be illuminated with the cool-light lamps. When arranging a lighting set up for showroom, the colour temperature can help to create an advantageous effect when accentuating the natural colour and finish of a gemstone.

Colour rendering and colour rendering index

When setting up lights in showrooms, it is important to remember that the colour characteristics of illuminator model play a vital part in purchase-related decision making; therefore it might be more preferable to use illuminators with a higher colour rendering index.  Colour rendering index (Ra) determines the way of how the colours of the objects when illuminated with a specific light relate to the colours of these objects as illuminated with the reference standard light (the Sun).

The key light

The key or the directed light is intended for illuminating the central filmed object for the fullest revelation of its appearance. Light's coherence should be at an intermediate level between the hard and the soft light.

The image shows the lamp LBE-151-CW for the key ("fill") light.

When positioning illuminators for the 3 point lighting layout, it is important to leave at least 30°- 45° angle for directing the key light onto the focus subject from the source located either to the right or to the left from a customer.

Positioning a key light illuminator at a 45° degree angle to a focus object (as shown in the picture) will be the most beneficial in revealing the object's surface texture and enhancing its volume.

On what side of a jewellery item should the key light source be located? This will depend on the following considerations:

• The most appealing side for demonstrating the item; its advantages should be enhanced and any possible faults should be toned down;
• Additional light sources (window, general lighting in the showroom etc.): if any of such sources are present, the key light should be following the direction of the light from additional sources;
• Whether the light sources harmonize with each other: closely positioned items should be lit from the same side, otherwise they might look out of sync with the overall shelf arrangement;
• Adjusting to real-life circumstances: if one side of the display space is restricted with an end wall which makes it impossible to ensure a 45° degree angle, it would make better sense to position the key light source in the opposite side of a display shelf.

When the key light source is in a correct position, it allows gem facets to produce the so-called "sparkles" that liven up the visual appearance of a gemstone. Observe shimmering in gemstone cuts and light flashes on chain links made with a diamond finish. However, if the illuminators are located at every available space, this will create an uncomfortable level of shine in customer's eyes when they're examining the display unit. Avoid situations where the light from display illuminators could be pointing straight into customers' eyes through a display unit glass. To do this, put yourself in your customer's position and move your head around from one side of the display unit to another to see how comfortable it feels.

When the key light source is illuminating the object from a position located either to the left or to the right of the customer, the horizontal angle should be maintained at 45°. But at what vertical angle should the light be directed?

Experts prefer to position the key light source near a camera or in such a way that the vertical angle is less than 30°. Filming in a confined space often compels for arranging this solution.

However, when reducing both horizontal and vertical angles the following issues might arise:

• This can obstinate any effects of dimension and volume, which is undesirable unless you are trying to achieve this impression deliberately as an artistic solution;
• This can create an undesirable effect of shadows from the key light appearing at the back of the display unit directly behind the item, i.e. at the location where this is least wanted.

Using a large semi-opaque dispersing screen made of either fabric or milky acryl can allow creating a soft light effect when the key light source is directly above an object. Sometimes, a thin sheet of special "milky" glass can be used for this purpose. Exceptional situations can require using special light screens, such as units made by Griffolyn or Dedotec (USA, Germany).

The Back light

The Back light is used for highlighting a filmed object against the background items by means of creating a radiant aura around it.  The back light can be created by illuminating units of a lesser capacity than the key light sources. This is due to the fact that back light illuminators are often located closer to an object then the key light sources. Besides, providing the object is not too large, increasing the intensity of its illumination can be achieved by focusing the light stream.

The Fill light

The Fill light is used for illuminating the whole shelf; this creates a dimensional effect throughout the display space and also highlights the filmed objects against the background of stands, supports and "neck models". Please remember that the back light is intended for illuminating the rear side of a filmed object, while the fill light is illuminating the front of the display!

The Fill light can be supplied by any light sources, including LEDs, providing they produce a homogenous illumination for jewellery items and have a large enough capacity.

If a jewellery item has a lot of small details making its surface texture somewhat intricate (such as in different compositions of white iron pyrites), then the fill light source should be positioned on the same side from a customer as the source of a key or directed light.

If we reduce the ratio of brightness between the key and the fill lights down to 1:1 where the intensity of the directed light matches with that of the fill light, this would allow for additional furthering of such effect.  If you look at the attached pictures of a gem-encrusted jewellery box, you can see that the first picture was made with the low ratio of brightness between the key light and the fill light (soft lighting). The second picture portrays a high ratio arrangement.