X-Git-Url: http://git.kpe.io/?a=blobdiff_plain;f=dof.lisp;h=ee9250a745c0d613716cdc405e798f8a8e191019;hb=7ba9d73cc35ce3fa0b2fc9e1145f6cafd4b73d0d;hp=4117c5a0f7d703dacce30a0e2cd51315c211945f;hpb=42befba0efb70b244c70edf76dbb1c5d012bb685;p=cl-photo.git

diff --git a/dof.lisp b/dof.lisp
index 4117c5a..ee9250a 100644
--- a/dof.lisp
+++ b/dof.lisp
@@ -49,25 +49,34 @@ Default resolving power is 5 lpm at 25cm."
     (values coc print-magnification)))
 
 (defun coc-pixels (imager pixels)
-  "Returns circle of confusion based on pixel size."
+  "Returns lpm and circle of confusion based on pixel size."
   (when (and (consp imager) (consp pixels))
-    (values (float (* 2 (/ (car imager) (car pixels))))
-            (float (* 2 (/ (cdr imager) (cdr pixels)))))))
+    (let ((coc-w (float (* 2 (/ (car imager) (car pixels)))))
+	  (coc-h (float (* 2 (/ (cdr imager) (cdr pixels))))))
+    (values coc-w coc-h (/ 1. coc-w) (/ 1. coc-h)))))
   
 (defun coc-pixels-format (format)
   "Returns circle of confusion based on pixel size."
   (coc-pixels (imager-dimensions format) (pixel-dimensions format)))
 
-(defun coc-airy (f-stop)
+(defun coc-airy (f-stop &optional (wavelength 0.000512))
   "Return the circle of confusion based on the airy disk."
-  (let ((airy (/ f-stop 1500)))
-    (float (* 2 airy))))
+  (float (/ 1 (rayleigh-limit f-stop wavelength))))
+
+(defun rayleigh-limit (f-stop &optional (wavelength 0.0005))
+  "Returns the rayleigh limit in line pairs per mm (MTF 9%) as well as the MTF50"
+  (let ((rayleigh (float (/ 1 1.22 f-stop wavelength))))
+    (values rayleigh (* 0.46 rayleigh))))
+
+(defun maximum-sharpness-aperture (format &optional (wavelength 0.0005))
+  (multiple-value-bind (coc-w coc-h lpm-w lpm-h) (coc-pixels-format format)
+    (declare (ignore coc-w coc-h))
+    (/ 1. (* 1.22 wavelength (/ (min lpm-w lpm-h) 0.46)))))
 
 (defun dof-mm (focal-length f-stop distance coc &key (pupil-factor 1))
   "Returns depth of field based on focal-length, f-stop, distance, and coc.
 Six values are returned:
-near dof, far dof, total dof, near point, far point, magnification,
-blur size at infinity (mm).
+near point, far point, total dof, magnification, blur size at infinity (mm).
 Circle of confusion can either be a number or keyword designating format."
   (let* ((aperture (/ focal-length f-stop)) 
          (numerator-1 (* (- pupil-factor 1) (- distance focal-length)
@@ -120,3 +129,9 @@ Output: NEAR-POINT, FAR-POINT, TOTAL-DOF, MAGNIFICATION, BLUR-SIZE-OF-INFINITY-P
 
 (defun effective-aperture (focal-length distance aperture)
   (* aperture (bellows-factor focal-length distance)))
+
+(defun mtf-scanner (freq dscan-freq &optional (order 3))
+  (abs (expt (kmrcl:sinc (* pi (/ freq dscan-freq))) order)))
+
+(defun freq-mtf-scanner (dscan-freq mtf &optional (order 3))
+  (* dscan-freq (/ (asin (* x (exp  (/ (log mtf) order)))) pi)))