The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

The New Hotness

  • Long-duration Exposure: Neutral Density Filters vs. Color Shift

    The view through the front window (1950-vintage glass + storm window) at 1/500 s, f/4, ISO 100, auto-exposed to EV 0:

    Front yard - normal exposure
    Front yard – normal exposure

    The same view, using stacked 2 + 4 + 8 ND filters, at 1/3 s, f/4, ISO 100, auto-exposed to EV 0:

    Front yard - ND2-4-8 filters
    Front yard – ND2-4-8 filters

    That blur to the left of the mailbox is a passing car, which is the whole point of heavy ND filtering: you can use absurdly long shutter times and still get a decent exposure.

    I cannot explain the fact that the ND filters allegedly reduce the light by 14 stops, but the actual (auto) exposure increases by about 7 stops. They’re cheap non-coated K&F Concept Digital filters, of course, but …

    There’s an obvious color shift toward red / magenta.

    This is a placeholder so I can pick up the thought later on…