The fields with the red border are required.
 Useful Optical Formulas (Prepared by : Gener Gatmaitan, 6/4/2012 for ios OpticsTM) Reflection Factor P = 2n/(n2 + 1) n is the refractive index of glass Refractive index of glass @ Helium (587.6nm) d line = Reflection Factor = Optical Density and Transmission D(ג) = Log 1/T(ג) D is the optical density and T is the transmittance Optical Density (D(ג)) = Transmittance (T(ג)), given D(ג) = % Transmittance (T(ג)) = % Optical Density (D(ג)), given T(ג) = Abbe Number vd = (nd - 1) / (nF - nc) vd is the abbe number nd is the refractive index at He line (587.6nm) nF is the refractive index at H line (486.1nm) nc is the refractive index at H line (656.3nm) Refractive index at He line (587.6nm) nd = Refractive index at H line (486.1nm) nF = Refractive index at H line (656.3nm) nC = Abbe Number vd = Temperature Conversion Farenheit to Celcius oF = oC Celcius to Farenheit oC = oF Glass Combination Transmittance (assume adhesive index matched to glass) External Transmittance of 1st glass T1 = % External Transmittance of 2nd glass T2 = % External tranmittance of combination % Internal Transmittance of glass Kx = Ln (T1/T2) / (t1 - t2) Kx is the absorption ratio T1 is the external transmittance at thickness t1 T2 is the external transmittance at thickness t2 t1 is the glass thickness with T1 transmittance t2 is the glass thickness with T2 transmittance τ = ℮ (thickness x Kx) τ is the Internal transmittance Glass thickness t1 = mm External transmittance T1 = % Glass thickness t2 = mm External transmittance T2 = % Thickness of glass t3 = mm, (values from t1 ~ t2) Internal Transmittance τ = % Glass Thickness vs Transmittance Thickness of glass (catalog thickness) t1 = mm Refractive Index (catalog value) n = Internal Transmittance at t1 (catalog value) τ1 = % Computed Reflection Factor P = Transmittance with known thickness of glass Thickness of given glass t2 = mm Internal Transmittance at thickness t2 τ2 = % External Transmittance of glass at t2 T2 = % Thickness Calculation with known glass transmittance Desired External transmittance of glass T3 = % Computed Internal Transmittance τ3 = % Thickness of glass at transmittance T3 t3 = mm