X-Git-Url: http://git.kpe.io/?a=blobdiff_plain;f=dof.lisp;h=d8677d307ad3b40d873f6f4180e66c023f8456a4;hb=3cd2e30d32c063639f4963d1de672f496c79e0cf;hp=4117c5a0f7d703dacce30a0e2cd51315c211945f;hpb=42befba0efb70b244c70edf76dbb1c5d012bb685;p=cl-photo.git diff --git a/dof.lisp b/dof.lisp index 4117c5a..d8677d3 100644 --- a/dof.lisp +++ b/dof.lisp @@ -19,24 +19,34 @@ (in-package #:photo) -(defun coc (imager-size &key (lpm 5) (minimum-distance 250) +(defun sort-size (size) + "Returns a cons pair with the smaller size first." + (if (>= (car size) (cdr size)) + (cons (cdr size) (car size)) + (cons (car size) (cdr size)))) + +(defun print-magnification (imager-size print-size) + "Returns the magnification required between an imager and print sizes +while taking crop into consideration." + (setf imager-size (sort-size imager-size)) + (setf print-size (sort-size print-size)) + (float (max (/ (car print-size) (car imager-size)) + (/ (cdr print-size) (cdr print-size))))) + +(defun coc (imager-size &key (lpm 5) (minimum-distance 250) (viewing-distance 250) (print-size (output-dimensions :8x10in))) - "Returns circle of confusion in mm and print magnification for a format. + "Returns circle of confusion in mm and print magnification for a format. Default resolving power is 5 lpm at 25cm." + (let* ((magnification (print-magnification imager-size print-size)) + (resolution-factor (/ (* magnification lpm minimum-distance) viewing-distance)) + (coc (/ 1.0d0 resolution-factor))) + (values coc magnification))) - (let* ((imager-diagonal (diagonal (car imager-size) (cdr imager-size))) - (print-diagonal (diagonal (car print-size) (cdr print-size))) - (resolution-factor (/ (* lpm print-diagonal minimum-distance) - (* imager-diagonal viewing-distance))) - (coc (/ 1.0d0 resolution-factor)) - (print-magnification (/ print-diagonal imager-diagonal))) - (values coc print-magnification))) - -(defun coc-format (format &key (lpm 5) (minimum-distance 250) +(defun coc-format (format &key (lpm 5) (minimum-distance 250) (viewing-distance 250) (print-size (output-dimensions :8x10in))) - "Returns circle of confusion in mm and print magnification for a format. + "Returns circle of confusion in mm and print magnification for a format. Default resolving power is 5 lpm at 25cm." (let* ((format-size (imager-dimensions format)) @@ -49,27 +59,38 @@ 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). -Circle of confusion can either be a number or keyword designating format." - (let* ((aperture (/ focal-length f-stop)) +near point, far point, total dof, magnification, blur size at infinity (mm). +Circle of confusion can either be a number or keyword designating format. +Reference: http://www.vanwalree.com/optics/dofderivation.html" + (let* ((aperture (/ focal-length f-stop)) + (hyperfocal (hyperfocal focal-length f-stop coc)) (numerator-1 (* (- pupil-factor 1) (- distance focal-length) coc focal-length)) (numerator-2 (* pupil-factor aperture focal-length distance)) @@ -77,38 +98,50 @@ Circle of confusion can either be a number or keyword designating format." (denominator-2 (* pupil-factor aperture focal-length)) (near (/ (+ numerator-1 numerator-2) (+ denominator-1 denominator-2))) - (far (/ (- numerator-1 numerator-2) - (- denominator-1 denominator-2))) + (far (when (/= denominator-1 denominator-2) + (/ (- numerator-1 numerator-2) + (- denominator-1 denominator-2)))) (mag (float (/ focal-length (- distance focal-length)))) (infinity-blur-diameter (/ (* mag focal-length) f-stop)) - (depth (- far near))) + (depth (when far (- far near)))) + (when (or (>= distance hyperfocal) + (and (null far) (>= distance (* hyperfocal 0.99)))) + (setq near (/ hyperfocal 2) + far most-positive-short-float + depth most-positive-short-float)) (values near far depth mag infinity-blur-diameter))) ;; Simplified calculation for symmetric lens (defun dof-symmetric-mm (focal-length f-stop distance coc) "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, +near point, far point, total dof, near point, far point, magnification, blur size at infinity (mm). -Circle of confusion can either be a number or keyword designating format. -Pupil factor is the ratio of the exit to enterance pupil diameters." +Circle of confusion can either be a number or keyword designating format." (let* ((aperture (/ focal-length f-stop)) + (hyperfocal (hyperfocal focal-length f-stop coc)) (numerator (* distance coc (- distance focal-length))) (factor-1 (* focal-length aperture)) (factor-2 (* coc (- distance focal-length))) (near (- distance (/ numerator (+ factor-1 factor-2)))) - (far (+ distance (/ numerator (- factor-1 factor-2)))) - (mag (magnification focal-length distance)) + (far (when (/= factor-1 factor-2) + (+ distance (/ numerator (- factor-1 factor-2))))) + (mag (magnification :focal-length focal-length :object-distance distance :units :mm)) (infinity-blur-diameter (/ (* mag focal-length) f-stop)) - (depth (- far near))) + (depth (when far (- far near)))) + (when (or (>= distance hyperfocal) + (and (null far) (>= distance (* hyperfocal 0.99)))) + (setq near (/ hyperfocal 2) + far most-positive-short-float + depth most-positive-short-float)) (values near far depth mag infinity-blur-diameter))) (defun dof (focal-length f-stop distance coc &key (units :mm) (pupil-factor 1)) "Returns the Depth of Field. -Input: FOCAL-LENGTH, F-STOP, DISTANCE, CIRCLE-OF-CONFUSION. +Input: FOCAL-LENGTH, F-STOP, DISTANCE, CIRCLE-OF-CONFUSION. Output: NEAR-POINT, FAR-POINT, TOTAL-DOF, MAGNIFICATION, BLUR-SIZE-OF-INFINITY-POINT-IN-MM." (multiple-value-bind (near-point far-point total-dof mag blur) - (dof-mm focal-length f-stop (length->mm distance units) coc + (dof-mm focal-length f-stop (length->mm distance units) coc :pupil-factor pupil-factor) (values (mm->length near-point units) (mm->length far-point units) @@ -120,3 +153,7 @@ 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))) +