Photography

Is there any reason to use P mode?

Does program mode have any real use when aperture priority and shutter priority already exist?

Asked on PIXLS.US,

Not for anyone in the thread, who between them use manual, aperture priority or shutter priority. Two arguments for it survived: it is a workable way in for someone who has not yet internalised how aperture, shutter and ISO trade against each other, and it is the descendant of a genuinely useful older idea.

What people use instead

  • Aperture priority with auto-ISO was the most detailed alternative offered, and the mechanism is the point: set a base ISO and a minimum shutter speed, and the camera holds base ISO until the shutter would fall below that minimum, at which point ISO rises instead.
  • The result is that most frames are taken at base ISO without anyone thinking about it, and the ones that cannot be are handled automatically.
  • Others reported using manual almost exclusively, some moving to saved custom modes, which are manual with a different set of settings per slot.
  • One reply preferred the arrangement where each parameter can individually be set to auto or to a fixed value, rather than choosing between named modes at all.

The argument for keeping it

One reply pushed back on the whole framing, and it is the most interesting thing in the thread. Nothing is complicated to somebody who already knows it; understanding how the three exposure controls trade against each other is a stage you pass through, and until then program mode is a reasonable way for a curious person to use a real camera. The case given was someone wanting to start without first being taught the theory by a partner explaining that it is not that complicated.

Where it came from

  • It was the default on film cameras, one reply noted, and was the point-and-shoot setting.
  • Another traced the idea further back, to handheld meters whose paired aperture and shutter scales show every equivalent exposure at once, and to cameras that linked the two controls so that opening the aperture shortened the shutter automatically.
  • That is exactly what program mode does. Seen that way it is not an oddity but the automated form of how exposure was set before cameras could do it themselves.

The honest summary

  • One reply described it as auto with a semi-manual override, behaving like full auto but without firing the flash unnecessarily.
  • The same reply named the practical problem: you can bias it towards shutter or aperture, but you have to do so for every shot, which gets tedious quickly.
  • Which is most of the answer. Aperture priority reaches the same place in one move and then stays there.