function f = achromat1(v) % Achromatic lens: % f(1) = power error % f(2) = axial chromatic aberration global cv th rn dn; cv(2:3)=lens_shape(v(1),1,rn(2)); cv(4:5)=lens_shape(v(2),0,rn(4)); yap = 50/8; uco = tan(2.0*pi/180); ya = parax([yap 0],cv,th,rn); usolve = -0.125; n=5; %yn=ya(n,1); %if (abs(yn)>1e-6) % cv(n)= -(rn(n)*usolve-rn(n-1)*ya(n-1,2))/((rn(n)-rn(n-1))*yn); %end %ya(n,2)=usolve; yc = parax([0 uco],cv,th,rn); power = -ya(n,2)/ya(1,1); perror = (yap*yap)*(power - 1/50); % power error %[w wsurf petz] = ford(ya,yc,cv,th,rn,1); w = ford(ya,yc,cv,th,rn,1); wv = chromatic(ya,yc,cv,th,rn,dn,1); f(1) = perror; f(2) = wv(1); f = f(:);