v1-v2 comparison

Some positive results.

v2 is uniformly higher than v1, but at nearly 1.8, not 1.5. Some of this could be because of a different calibration curve (which is worth checking on; I'll do that later).

While the pixel-to-pixel comparison yields values ~1.75, the aperture photometry is perhaps even more severe:

Those are a difference of a factor of 2.5, which is rather enormous.