Tag: Colorimeter

Spectral photometers (or spectrophotometers) are high-quality colorimeters that can measure and accurately describe any colour.
The measuring instrument achieves this by illuminating the measuring surface with the entire spectrum of the visible light. The remission values of certain wavelengths together give the measured value, often this is output in Lab (measuring mode freely selectable from M0 to M2). The spectral measurements can also be stored directly.

High-quality proof printers have their own spectrophotometers to verify the print directly.

Spectrophotometers are high-quality colorimeters that can measure and accurately describe any colour.
The measuring instrument achieves this by illuminating the measuring surface with the entire spectrum of the visible light. The remission values of certain wavelengths together give the measured value, often this is output in Lab (measuring mode freely selectable from M0 to M2). The spectral measurements can also be stored directly.

High-quality proof printers have their own spectrophotometers to verify the print directly.

Colour measurement is used to determine the exact colour location of a colour in a colour system.

There are three methods:

The Tristimulus Method:
A tristimulus colourimeter shines an internal light source onto the surface of the colour sample.The reflected light passes through three filters – red, green and blue – which determine the intensity of these color components.
The reflected light passes through three filters – red, green and blue – which determine the intensity of these colour components.

The Spectral Method:
A spectrophotometer works in a very similar way – but has not only three, but 31 filters that measure 31 different wavelengths of the reflected light. Thus the spectral method is one of the best methods for measuring colour.

Equality Method:
Here, a measuring device (or the eye) is used to compare the colour sample with standard colour samples until all samples are considered identical by the observer. However, this is assessed subjectively by the viewer, which is why the other methods of colour measurement are preferred in practice.

A colour measuring device for measuring/comparing colours.
It is often used for the calibration of monitors or in biology/chemistry for analysis. More powerful devices, such as the spectrophotometer, can measure colours spectrally and are also used, among other things, for proofs to verify or calibrate printers.

In order to describe colors accurately and avoid metamerism, modern color measurement is increasingly no longer carried out via colorimeter that can measure one color spot in the 3-dimensional colorspace LAB, but by spectral measurement, ie the recording of the complete emission spectrum or reflection spectrum of a color.

Even with cameras, this technology is used. So images are no longer to be photographed in RGB, but with systems such as the Can:View, images can can be photographed in 16 individual spectra between 400 and 700 nm with 11 million pixels. Each of these pixels is thus defined spectrally.

In retouching, one type of light can be used, D50 or D65 for example, and – since the spectrum of the illuminant is known – the image can be easily processed by the multi-spectral data with a mouse click on the required standard light for retouching.

At present, with the can:view (softproof system) and the can:scan (camera system) a complete system is on the market for recording and edition images with multispectral data. Outside catalog manufacturers and fashion companies, the technology has not yet arrived in the broad market.

With colour management it can be achieved that colours on different devices like cameras, scanners, monitors, laser, inkjet, offset printers and many more can be reproduced as similar as possible to each other.

Therefore device-dependent colour spaces must be used. A well working colour management will map the gamut of each device as Monitores and printer and device-independent colour spaces such as Adobe RGB 1998

Modern colour management systems use instruments such as the X-Rite i1 Pro 2 and related colour management software that creates and manages colour profiles within application programs such as the Adobe product range provides.