Huygens Professional User Guide

d2rd 2=πr 2 dand thus r = ------π(EQ 4)For a square pinhole c shape = 1 ⁄ π = 0.564. For circular pinholes c shape = 0.5 to just convertfrom diameter to radius.Airy disk as unit forthe backprojectedradius of a square pinholeThe relation between the edge size of square pinhole in Airy disk units and the backprojectedradius is a combination of (EQ 2) and (EQ 4). Taking into account that (EQ 2) already convertsa diameter into a radius we get:r b=0.69λ ex N----------------------------------------- AirydisksNA(EQ 5)with N Airydisks the number of Airydisks.Computing the backprojected pinhole distance in Nipkow spinning disksAs is the case for the backprojected pinhole diameter, the distances between the pinholes inspinning disks must be divided by the system magnification. For the most used Yokogawa, forexample, the pinhole distance is 2.5 µ. You can check this by stopping the disk. So with an100x lens the backprojected distance is about 2.5 µ.Pinhole radius tablesIn the case of the Leica TCS4d, the Biorad MRC500/600, the Zeiss LSM310 and the ZeissLSM410 type microscopes the pinhole geometry and system magnification is known resultingin the conversion formulas from the following tables:Leica confocal microscopesTCS 4D, SP1, NTThe size of the square pinhole is given as an 8-bit number which maps to the physical pinholeradius given in the following table:TABLE 1. Leica TCS4d pinhole parametersTCS4d Range begin Range endReported parameter (p 8 ) 0 255Size (micron) 20 630 (earlierreported as 500)Pinhole geometrySystem magnification 4.5squareBackprojected pinhole 295 p 8 + 2508radius (nm) -------------------------------- (EQ 6)If the pinhole is specified in Airy disk units, see “Airy disk as unit for the backprojected radiusof a square pinhole” for information on how to convert to a backprojected radius.m obj24 The Huygens Professional User Guide