Definition #1 (used for a single exposure)

“An uninterrupted interval of time, of any length”

Under definition #1, a “moment” is defined not by its length but by its uninterrupted nature.

Once a “Definition #1” moment is interrupted or ended by any means, resumption even of the same activity constitutes a separate period of time — a separate moment — and not a continuation of the first moment.

The Definition #1 kind of “moment” can be years, decades, or even centuries long: “At this moment in history, almost two-thirds of the world’s population lives on one continent (Asia).”

Definition #2 (used for multiple exposures)

“A very brief period of time”

For definition #2, P5 of the Trust Test employs one second, the briefest universally used time unit (see also #1506).

As per P5, in any situation that there is control over the combining of exposures, all exposures being combined to make the photo must be started within the same single second or the photo cannot qualify as TTG.

Note that a single-exposure, undoctored photograph remains the gold standard for viewers and the reference point for TTG.

That’s why P4 and P5 of the Trust Test are written to ensure that even when multiple exposures are combined, the result will look like a single-exposure, undoctored photograph.

For more on “moment”-related issues, see the FAQ on P5