TTG Plus > FAQs > This is FAQ 15


On P5 of the Trust Test

“One moment”

  • 1501. What’s the point of P5?

    In light of Characteristic #5 of trusted photographs, P5 ensures that every TTG-qualified photograph is the record of “one moment.”

    That applies regardless of whether a moment is defined as “a very short period of time” or as “any uninterrupted period of time.”

  • 1502. Why does TTG allow for combining exposures when news organizations traditionally did not allow it?

    Because millions of non-deceptive photos are now made every hour with smartphones that automatically combine multiple exposures.

    More on TTG’s allowance for combining exposures

  • 1503. But will the public trust news photographs that are made by combining exposures?

    Presumably yes, as the public already trusts news photographs that are made by combining exposures.

    Anytime there is a citizen-supplied spot-news photo that was taken with a smartphone, there’s a good chance that it was created by instantly combining multiple exposures.

  • 1504. Why does P5 allow the combining of exposures recorded outside of “the same single second” in situations when the photographer has no control over the combining?

    Because the photographer has no control over the combining in those situations.

    To not allow smartphones' automatic exposure-combining would be to bar from TTG millions of smartphone photos made every hour.

  • 1505. Do TTG photographers ever need to program their cameras to combine exposures in order to meet the Trust Test?

    No, manually combining exposures is never necessary to meet the Trust Test.

    Any normal, functioning camera or device can capture a sufficient depth of focus and enough dynamic range to meet the requirements of P7.

    See also #804.

  • 1506. Why does P5 put a 1-second limit on manually combined exposures instead of some longer period?

    Among other reasons, because “one second” is the briefest universally used time unit and thus is the most obvious expression of “one moment.” More

  • 1507. But why doesn’t TTG allow a longer time limit for combining exposures when there is no motion or change in the scene?

    Two reasons:

    1. Because to do so would allow too much room for abuse of the definition of “a moment” (which is one of the 9 characteristics that viewers depend on TTG photographs to have). See also #5 in 1506-more

    2. Because to do so would allow too much room for abuse of the definition of “motionless.”

    Even a cursory web search for focus-stacked or HDR photographs of purportedly “motionless” scenes quickly reveals that photographers are inclined to present various nature and landscape scenes as being completely “motionless” when the scene clearly is not.

  • 1508. Besides the “one-second” limit in P5, what other limitations does TTG put on combined-exposure photographs?

    The other limitations imposed by the Trust Test are listed in the guide to combining exposures.

  • 1509. Why does P5 say “No pictorial information may be added” rather just saying “no combining of exposures”?

    (P5 is here.)

    Because TTG allows for both dark-frame subtraction in digital photographs and for flashing when printing photographs on paper.

    Both processes can happen outside of the one-second window without disqualifying the result from TTG; neither technique involves importing “pictorial information.”

  • 1510. What if the way I want to record a scene requires combining multiple exposures that start over a period of more than one second?

    You will have to decide between recording the scene the way you want (and not worrying about TTG) vs. keeping the photograph eligible to meet P5 and qualify as TTG.

    Numerous highly popular photographic actions that are routinely done in the digital era disqualify the resulting photos from TTG, including the three things singled out in “A” of P2.

    But any standard like TTG will necessarily involve excluding some examples; see #428.

  • 1511. What if I can imagine some bizarre ways of combining two exposures that begin in the same second, one very short and the other lasting much longer than one second?

    Imagine away! If it meets P5, it may end up qualifying as TTG.

    But remember that the image has to meet not only P5; it also has to meet the rinairs standard for non-misrepresentation in P7 and the non-deception requirements of P8.

  • 1512. Instead of the sasibe standard and the satode test, why doesn’t the Trust Test just solve those problems by declaring a specific maximum exposure length for single-exposure photographs?

    Sasibe | Satode | Sashimi

    Because rinairs doesn’t declare a universal “maximum exposure length,” so any attempts to set such a length would run into the problem of arbitrariness.

    More



See also the “P5” tab on “How undoctored photographs work”

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