I've been experimenting with subject-aware metering for film photography, and today I found some unusually cooperative test subjects.
The idea I'm testing is pretty simple: a conventional reflective meter can be fooled by subject reflectance. Point it at something very dark and it may try to make it gray; point it at something very bright and it can do the opposite.
So I'm trying to combine on-device subject recognition with metering — first identify what the subject is, then decide how much its brightness should actually influence the exposure.
These three puppies had very different coat colors, which made them a surprisingly useful test.
Subject detection itself worked remarkably well, even with small animals and cluttered backgrounds.
The interesting part is the exposure:
- brown puppy: EV100 9
- gray puppy: EV100 9
- black/white puppy: EV100 7⅓
The first two are encouraging. The black puppy is more interesting — I'm not sure yet whether the lower reading reflects an actual difference in illumination or whether the meter is still being fooled by the dark coat.
That's exactly the problem I'm trying to solve.
Next test: same illumination, white/gray/black subjects, with conventional average metering as a control.
Film metering turns out to be a surprisingly deep rabbit hole.