(defun format-match-p (format-spec format)
- (when (or (eql format-spec (getf format :format))
- (member format-spec (getf format :nicks)))
- t))
+ (let ((key (ensure-keyword format-spec)))
+ (when (or (eql key (getf format :format))
+ (member key (getf format :nicks)))
+ t)))
(defun find-format (format-spec)
(find format-spec +format-db+ :test 'format-match-p))
(:h2 "References")
(:ul
(:li
- ((:a :href "http://solo.colorado.edu/~walawend/TwilightLandscapes/DoF_article.shtml")
- "http://solo.colorado.edu/~walawend/TwilightLandscapes/DoF_article.shtml"))
+ ((:a :href "http://www.normankoren.com/Tutorials/MTF.html")
+ "http://www.normankoren.com/Tutorials/MTF.html"))
(:li
((:a :href "http://www.vanwalree.com/optics/dofderivation.html")
"http://www.vanwalree.com/optics/dofderivation.html"))
(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)
+ (/ 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.