From edo@as.arizona.edu Fri Jan 4 14:59:46 2002 Date: Thu, 29 Nov 2001 16:59:11 -0700 (MST) From: E. Olszewski To: ggwilli@as.arizona.edu, mlesser@as.arizona.edu Subject: Jim's email " Ed, I have evaluated the chip in L2 and recommend that we proceed with the part, then paint the area black before installing the lens. The chip is big and ugly, but the area it extends into the clear aperture is only about 8 mm across. The beam is 200 mm across here, so worst case, it affects 0.16%. In fact, we can do much better then this. If we clock the chip so that it is oriented along the sides (not the corners) of the filters and the CCD, then it will never be seen by the focal plane. We do need to make sure that we do NOT put it on the side of the guider. Steve is proceeding with the spherical surface, assuming that he does not need to correct it. The option for fixing the lens would be to regenerate the surface. We would lose about 1 mm of thickness and several days. Since we can simply orient the part to make the problem go away, I recommend we accept the part with the ding in it. If you have questions, please call me. Otherwise, please give Steve the okay to finish the lens as is. Jim "