On 29 January 1997 I observed the dipper asterism in M67 in J, H, and Ks to determine the scale of the f/5, f/10, and f/20 cameras of GRIM II. I used the astrometry of Montgomery et al. (1993, AJ, 106, 181, although stars 23 and 28 are mislabelled in their finding chart). I find no evidence for any wavelength dependence. I find the scales are 0.473, 0.236, and 0.113 arcsec/pixel. I estimate uncertainties of order 0.001 arcsec/pixel from an assumed uncertainty in the reference positions of order 0.1 arcsec and a span of order 200 pixels. My values differ by about 2% from the values quoted on the APO detectors WWW page (0.482, 0.238, and 0.111 arcsec/pixel); I have no idea where these values come from or what their likely uncertainties might be. Alan Watson APO APO APO APO APO Apache Point Observatory 3.5m APO APO APO APO APO This is message 37 in the apo35-grim archive. You can find APO the archive on http://www.astro.princeton.edu/APO/apo35-grim/INDEX.html APO To join/leave the list, send mail to apo35-request@astro.princeton.edu APO To post a message, mail it to apo35-grim@astro.princeton.edu APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO APO