r10463: update cameras

diff --git a/cameras.lisp b/cameras.lisp
index 814e387173ec6952dc448c754f7f25d1e6306a65..d914d0bad6eb4f123f6022f218bb5afe86f78e09 100644 (file)
--- a/cameras.lisp
+++ b/cameras.lisp
@@ -184,8 +184,10 @@ so the proper aspect ratio is used."
   "Return pixel size in micrometers."
   (let ((pixel-dim (pixel-dimensions format-spec))
        (imager-dim (imager-dimensions format-spec)))
-    (values (* 1000 (/ (car imager-dim) (car pixel-dim)))
-           (* 1000 (/ (cdr imager-dim) (cdr pixel-dim))))))
+    (when (and pixel-dim imager-dim)
+      (values (* 1000 (/ (car imager-dim) (car pixel-dim)))
+             (* 1000 (/ (cdr imager-dim) (cdr pixel-dim)))))))
+
 (defun output-dimensions (format-spec)
   "Returns the output dimensions in mm of a FORMAT."
   (getf (find-format format-spec) :output))