diff --git a/src/messages.c b/src/messages.c
--- a/src/messages.c
+++ b/src/messages.c
printf (" log for log scale \n");
printf (" normalize for linear histogram stretch \n");
printf (" equalize for histogram equalization \n");
- printf (" -c <min>:<max> \n");
+ printf (" -r <min>:<max> \n");
printf (" Clip output image to min-max range. Eg: \n");
printf (" 0:100 Use only values in the range 0-100 \n");
printf (" 100:0 Same as above, but negative image \n");
printf (" 10: Clip everything below 10 \n");
printf (" -n \n");
printf (" Negate the image \n");
- printf (" -q \n");
+ printf (" -q <value> \n");
printf (" quality factor. Defines the jpeg encoding quality \n");
printf (" Valid range: 0-100, default value: 100 (max.quality)\n");
printf (" -z <zoomfactor> \n");
printf (" Resize/Scale output image by <zoomfactor>. Eg: \n");
printf (" 0.5 Shrink output to half of input \n");
printf (" 2.0 Magnify output to double the size \n");
+ printf (" Allowed range: 0.01 to 4.0 \n");
+ printf (" NOTE: Zooming will be carried out after all other \n");
+ printf (" operations, before writing out jpeg image \n");
printf (" Output will be written to <fits_file_root>.jpg. Wild card\n");
printf (" entries allowed in <fits_file>; For eg: *.fits, m31*.fits\n");
printf (" ngc???.fits etc. \n");