Affiliation
American Association of Variable Star Observers (AAVSO)
Thu, 08/20/2020 - 19:23

VPhot handles saturated targets differently from saturated comps.  This can cause problems.

When a comp is saturated the photometry tools show the saturated comps in the report but automatically exclude them from the analysis.  When a target is saturated they go right ahead with the analysis and show no indication that the target is saturated.

This is not a big problem for the single image (untransformed) photometry tool since you load the user defined sequnce before viewing the photometry report.  You will see a saturated target then.

The problem comes with the Two Color Transform tool, where the images are loaded before the sequence.

If you are using the Two Color Transform tool, just eyeballing the images for defects before loading them in the tool is not enough.  You must also examine the images with your user defined sequence to be sure the target is not saturated.

I think this should be fixed for both tools.  Saturated targets should be blocked automatically, just like comps.

 Phil

Affiliation
American Association of Variable Star Observers (AAVSO)
images shared

Images demonstrating the problem have been shared with Ken Menzies.