We've heard the truism that you expose for the shadows
and expose for the highlights. That is true as far as it goes,
but it is only a truism, generally true but not completely accurate.
Since few of us are developing a dozen rolls of film every day, shot under studio conditions,
we are able to go a little further with our craftsmanship than to look at the time and temperature
chart on the darkroom wall.
If we allow the possibility of variable agitation,
from constant agitation to intermittent agitation,
every fifth minute or so,
we get a new mantra:
"Expose for the shadows,
develop for the midtones,
and agitate for the highlights."
For my own work, such at it is,
I recognize the situations when
I need to make strong choices in exposure and development,
and have worked out good answers for these particular problems.
An example would be using 220 film for portraiture.
My only choice for film is TXP,
the last of the wonderful Kodak films intended for shooting portraits
in traditional, flat, studio lighting. It compresses the shadows,
and adds separation to the high values, so faces are given attention
while the setting is diminished.
But I like to shoot in the light I find by windows, and 'found' settings
and rarely shoot in a studio anymore. For me, TXP simply makes highlights too bright when the sun is strong, and if there is a stray bit of sunshine, it makes a real problem. I SHOULD be shooting TMY or Tri-X. But if I want to shoot 220... I need to use TXP.
If I choose a developer like XTOL or D-76, dilute it to lengthen the development time, and agitate the film for 10 seconds every 5th minute, the 'belly' of the TXP curve diminishes, and TXP becomes almost like TX.
I still have to watch the highlights,
but it is much easier to use in the field. To work this 'magic, I have to re-balance the normal exposure and development with the minimum agitation safely possible; but this is what craftsmanship is all about.
Here is an illustration showing a normal TX curve, a normal TXP curve,
and the results of minimal agitation with dilute D76. XTOL works even better.
NOTE: it might not seem to be a big difference, but if it frees you from burning and freaking dodging for the rest of your life, it can't be all bad, can it ?