A pixel that reads at most half of its own sector's level on average, by more
than the bound a hot pixel's excess has to clear, is now masked as dead - the
mirror of the hot rule. Nothing but a defect keeps a pixel dark frame after
frame, and every reflection whose disk covers it is integrated short.
The finder now also runs on CCD sweeps (no sensor depth): a dead CCD pixel
reads its offset, far below any ring with background, and the hot rule's
ten-fold ratio does not depend on Poisson counts either.
Found on 5jk4 (ADSC Q4, 2304x2304): the last row and the first two columns
read the offset (~20 ADU against ~60-100 around them) and were unmasked.
Reflections touching them merged to large negative intensities, and one
observation at y=2298 with sigma 10334 swamped the outer shell's half-set
CC1/2 (3.9 %) and the overall CC1/2 (0.786; 0.998 at rc.174). With the
6630 dead pixels masked the fall-off is clean: CC1/2 0.998, cut 0.96 A
(fit 1.01 A), at --prepass-fraction 0.5 and 1 alike. Counting-detector
sets with low background are untouched (myoglobin X06DA: 0 dead).
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SVmAWnzCmRKAXVUCdc4iNi
leonarski_fandClaude Opus 5.5
1bb6d59bf7