But what happens if:
Originally Posted by MattKing
1) Expose at 100, develop at 200.
2) Expose at 100, develop at 50.
3) box speed 100, expose at 200, develop at 200.
4) box speed 100, expose at 50, develop at 50
As far as I now, when you over-expose or under-expose, you also correct the development time.
This is relevant because some manufacturers plot different density curves, keeping E.I. constant, according to development time. The difference you get is a steeper curve as development time increases. For instance check this link, but there are many others available online.
For instance, check the curve "Gevatone 66, G 74 c, 30 °C."
It seems you can get about 1 stops of extra speed (log exp from -1.8 to -2.4) when you increase development time from 20 to 70 seconds. This comes at the expense of increased contrast - the gradient of the curve gives you the Gama contrast. In this developer and temp combo, it goes roughly from 0.75 to 1.9 at the shadows to mid-tones for the longer development times.
This tells me it is not the same to "+1 push" to 200 and develop at 200 or expose at 100 and develop as 200.
As far as I can recall, and I might need to check again, Ansel Adams N+1 meant expose at N and develop as N+1. Right?
There should be as many options as in the table below. Anyone care to comment?