I have looked at the objects that were clipped from the starflat3 fit as a function of various quantities.
- Many of the clipped objects lie at the y edges of the chip
- More objects are clipped from the right side of the focal plane. CCD 7 has the most clipped objects.
- Most of clipped objects have the minimum pixel uncertainty of 0.01 from the fit.
- It doesn't vary too much from band to band.
Here is the number of clipped objects as a function of exposure. There seems to be a common pattern probably determined by the dither pattern in the different bands.
There is one exposure that has more objects clipped than any of the others, this is DECam_00153751. Here are the clipped objects as a function of the focal plane.
It looks like a poor fit over the exposure.