vances for Rayleigh Interference optics: a high-precision Rayleigh interference optical system mounted on an Xl ultracentrifuge (Laserarm from Spin Analytical); b large format interference camera from Philips (3,000 × 2,000 pixels); c data quality from the stock Beckman Coulter interference camera; d data quality from a large format Philips camera (1,024 × 2,048 pixels); e comparison of data quality as the residual noise from ten successive scans taken approximately 1 min apart. The residuals were calculated using WinMatch (available from http://www.rasmb.org) to optimize the fringe displacements. In c the residuals from the large format camera (rms 0.00017 fringe) are superimposed on those from the stock camera (camera rms 0.009). The increased number of fringes provided by the large format camera reduces the magnitude of the residuals over 50-fold, thus making it possible to acquire data at lower concentrations and improving the precision of analysis. Additional improvements can be expected from the Philips or any other large format CCD camera. Data supplied courtesy of David Yphantis and Jeff Lary
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