Ra 80 vs Ra 90: when high colour rendering is worth it

On paper Ra 80 and Ra 90 differ only slightly, yet in some places the eye sees it clearly. Here is when high colour rendering is genuinely worth having.

Many people who read about the colour rendering index conclude: “Ra 90 is better, so I should buy it everywhere.” Others think the opposite: “It is only ten points, nobody will notice.” The truth lies in between. The difference is not visible everywhere, but on certain surfaces and for certain tasks the eye picks it up immediately.

What ten points actually mean

Ra is the average result across eight test colours. A lamp with Ra 80 shows most of them acceptably, but some hues shift: reddish tones turn slightly brown, skin can look pale or greyish, and greens take on a slightly “plastic” quality. With Ra 90 these shifts are considerably smaller.

The difference is most noticeable in saturated colours. Saturated red (R9), which is not part of the general Ra calculation, is often weak in Ra 80 lamps. In most Ra 90 lamps it is better, because achieving a high Ra requires strengthening the red part of the spectrum. It is not an absolute rule, but it is frequently seen in practice.

Where the difference is visible

Placing Ra 80 and Ra 90 side by side, the difference shows most in:

• faces and hands, where skin looks livelier and its pink undertone more natural under Ra 90;
• meat, fish and fruit, where reds and oranges keep their saturation;
• wooden floors and furniture, where golden-red grain stands out more clearly;
• textiles and clothing, where similar dark colours (black, navy, dark brown) become easier to tell apart;
• paintings, photo prints and paint samples, where you can judge a colour's real appearance.

On white walls, grey concrete or plain surfaces the difference is hard to see. So choosing Ra 90 for a corridor, stairwell or storeroom changes practically nothing.

Where Ra 90 makes sense at home

There is no need to fit the whole home with high-CRI lamps. It is smarter to focus on these points:

• the mirror and make-up light in the bathroom;
• the kitchen worktop and dining table;
• a living-room wall with paintings, photos or a collection;
• the wardrobe or wherever clothes are chosen;
• a hobby table for sewing, painting or model building.

Elsewhere, such as the WC, hallway, balcony and utility rooms, Ra 80 is entirely sufficient.

Keep one more point in mind: the benefit of an Ra 90 lamp shows most when there is also enough light in that spot. In dim light the eye distinguishes colours poorly anyway, and the advantage of high CRI is lost. So when choosing a lamp for a mirror or a work table, check that it is bright enough as well as rendering colour well.

In workplaces and retail

In commercial premises the question is more practical: if colours look wrong, customers will see the product differently at home and be disappointed. In the sale of clothing, fabric, cosmetics, jewellery, flowers, meat and fish, high colour rendering directly affects sales. Design studios, print shops, dental and dermatology practices, and barbers and beauty salons belong to the same group.

In standard offices, classrooms, warehouses and car parks, Ra 80 is the widely accepted level, and extra investment does not bring the expected benefit.

What high CRI costs you

To reach Ra 90, the phosphor coating of the LED is formulated differently so that the spectrum is broader and more even. As a result, a lamp may give slightly less light for the same power draw, so efficiency drops a little. Production cost is usually higher too. That is not a reason to avoid Ra 90; it is simply the argument for using it where it is needed.

Checklist when choosing

• Are colour-based decisions made here: clothing, make-up, food, artwork?
• Are the surfaces saturated in colour, or mostly white and grey?
• Is Ra clearly stated on the box, or only a vague phrase like “high quality”?
• Are all lamps in the same zone at the same CRI level?
• If saturated red matters, is there information about the R9 value?

When the decision is hard, the most convincing test is to light an Ra 80 and an Ra 90 lamp of the same colour temperature side by side and place red fabric or fruit under them. A few minutes of comparison tells you more than the figures in a table.

You can send questions about colour rendering and other technical requirements for a specific project to Zaferoğlu Elektrik, which makes Zəfər İşığı lamps in Ganja, using the quote form on the website.