## PhotonAbsorptionRate

##### >Psychtoolbox>PsychColorimetric

[photonAbsorptionRate] =…

PhotonAbsorptionRate (irradianceInQuanta, irradianceS, absorptanceSpectra, absorptanceSpectraS, collectingDiameter)

Compute photons being absorbed per photoreceptor per sec, given the spectrum incident on the

photoreceptor array. We typically take the collecting area of a photoreceptor to be the inner segement

diameter.

Spatial units for this routine are um, which are convenient for photoreceptor calculations. Be sure

to convert your incident spectrum to these units. The retinal irradiance is passed in quantal units. Note

that routines EnergyToQuanta and QuantaToEnergy are available for your converting pleasure.

Can handle multiple photoreceptor types. Put each absopbtance spectrum in a row of matrix

absorptanceSpectra, put corresponding collecting diameters in column vector collectingDiameter.

Units:

photonAbsorptionRate: quanta/sec/photorecptor

irradianceInQuanta: quanta/um^2-sec-wlinterval

absorptanceSpectra: probability an incident quantum will be absorbed.

collectingDiameter (um^2)

05/06/03 lyin Wrote it

06/12/03 lyin Change the way variable being passed.

06/26/03 dhb Change computation of area to pi*r^2 rather than pi*d^2!

06/26/03 dhb Change to expect absorptanceSpectra and collectingDiameter in rows.

7/08/03 dhb Cosmetic.

7/09/03 dhb Take input in quantal units.

`Psychtoolbox/PsychColorimetric/PhotonAbsorptionRate.m`