Photo of a Wedge
One of the concepts of Ansel's Zone System is pre-visualisation - how a
real-life object will be rendered (in B&W) in a print. Nowadays we will
first see this on the screen. So can I predict/visualise what the camera will
show?
I tried a number of shots/situations, but I think the following captures the
essence of what I found.
As an experiment, I created a 9 equal step wedge (generated in Photoshop),
displayed it on a not very good LCD un-calibrated screen and photographed it!
This was hardly a contrast image and so well within the limits of the camera's
dynamic range and by adjusting exposures I should be able to work out what the
image will look like.
But I digress - I need to get back to Zones...
Incidentally, while I was testing exposures, I also tried different lenses. It was
quite incredible how much better a prime was compared to a zoom lens - obvious
really,
but I had never done a proper comparison before - well worth using a prime if possible. Also I had thought that a
Polaroid filter behaved differently with a digital
sensor and was not that effective, but it is well worth using.
I
found a bug/feature with the D700 Live-View and through sitting down and
really exercising the cameras, I learnt some attributes that were not in
the manuals - a real gain by just 'playing' with them.
I
also read that in the "old days" of digital processing, the built-in
tone curves in Nikon cameras were much "flatter" (like the linear tone
curve) and much more "accurate," without the tonal shifts, brightness
adjustments and aggressive S curves that you are now seeing with the
"default" curves in the D3 and D700. The reality is that these "flat"
tone curves didn't look pleasing right out of the camera, which made
post-processing necessary for almost every image in order to make it
look pleasing to the eye. Nikon has incorporated years of
experience into the "new" tone curves, automatically applying many of
the "corrections" that used to be required in order to produce a
pleasing image.
They say that if your goal is to
correctly render the mid-tone at 50% L Lab, you will need adjust the
midpoint in post processing, or expose with -0.3/0.5 exposure
compensation. (The EV exposure compensation will then correctly place the
mid-tone, but still implements the "tonal shift" of mid-tones in
relation to other tones in the image.)
'Twas much simpler
(?) in the film days!