Anomaloscope

A Anomaloscope or Spektralfarbenmischapparat is an optical instrument which assesses the color discrimination in the red-green- see, and a red-green color weakness can be diagnosed. It is also used for fitness examinations for bus drivers, train drivers, airline pilots, police officers, boatman, electricians and other professions.

The subject looks at it with one eye through an eyepiece on the test field on which a horizontal split in half circle is shown. On the lower half ( yellow box ) a spectral yellow ( 589.3 nm, middle of the two yellow sodium lines) is presented as a reference field. On the upper half (mixed box ) is a spectral red ( 671 nm Li line) and a spectral green ( 546.1 nm Hg line ) can be mixed by turning a fine drive, so that the color Enterprising in the mixing field a with the comparison field can adjust matching yellow tint or " assumes ", so that a complete yellow circle.

The Green Light ( Deuteranomale ) is to give the upper half circle to greenery, a Rotschwacher ( Protanomaler ) is set too much red.

There are various manufacturers of Anomaloskopen but all operate on the principle of the spectrometer.

The specifications for a Anomaloscope regulated the DIN standard 6160th This standard was withdrawn.

There are Anomaloskopen except for the red-green- assessment - the most common and safety aspects ( traffic lights, railway signaling ) most important - also Anomaloscopes that measure the blue - vision.

Nail Anomaloscope

When Anomaloscope by Willibald Nagel of Rotspalt is in position "0" for the mixing box is closed and the green gap fully open. In a position "73" is the maximum Rotspalt opened and the green gap closed. The yellow comparison scale is normally set to 15 ticks and is used to control the brightness of the yellow comparison field. The color Efficient sets a value of about 40 at fine drive, the more Protanomale, the Deuteranomale much less.

Anomaly quotient

A quantitative measure provides a abnormality quotient ( AQ also: quotient of anomaly ), the subject (Vp ), as compared to the settings (S) of color-capable (No) according to the Rayleigh 's equation is calculated from the average of repeated adjustments (P): AQ = [( 73 - P ) / P ]: [( 73 - N) / N]

This corresponds to the relationship: AQ = green component Vp x ( amount of red No [ = 40 ] ) / red component Vp x ( amount of green No [ = 33 ] )

Efficient color are in a range of AQ = 0.7 to 1.4. In Protanomalen an AQ of 0.1-0.6 with P values ​​obtained > 40 an AQ of 2-20 results in the case of Deuteranomalen with P values ​​<40 with a mean of 3.0. In Farbanopsien specifying a anomaly quotient is useless, he can mathematically take all values ​​from 0 to infinity.

When protanopes excite lights in the wavelength range of 500 nm, the two remaining components about equally, so the sensation arises here colorless or gray. In the still longer-wave spectral range, only one component is excited to varying degrees. The color discrimination is then performed only on the brightness. The curve of the spectral sensitivity is shifted to the short wavelength side. The sensation maximum is not in yellow, but more in the yellow- green range.

When deuteranopes the sensitivity curve for brightness is not moved, and there is no restriction in the red before.

Taking into account of changes and the Yellow Set some rules of thumb:

• The so-called food standard equation (40/ 15 = mixing box / yellow box ) is also accepted by protanopes and deuteranopes except by normal trichromats.
• A final equation ( pure green = 0 in the mixing box or pure red = 73 in the mixing box ) is accepted by protanopes and deuteranopes unlike brave color by varying the yellow screw:
• Protanope put it in the green box ( set to 0 in the mixing box ) a brighter yellow ( G 30-40 ) as a deuteranope.
• Protanope make the red plane (setting 73 in the mixing box ) a darker yellow (G = 1-4) as deuteranope, the loss of brightness in the red direction is a characteristic of the Protanopsie.
• Deuteranope leave the area of the yellow screw largely at 14-17.
• Anomalous trichromacy ( deuteranomaly, protanomaly ): Anomalous trichromats reject the food standard equation.
• Rule of thumb value for Deuteranomale = 20 /15 campaign.
• Rule of thumb for Protanomale = 60 / 10th