Histogram to Zone?

To get a conversation started ...

Has anyone devised an approach to use one's DSLR's Histogram to
determine a basis for zone calculations? Is it at all useful?

Collin
KC8TKA

Cheesehead wrote:
To get a conversation started ...

Has anyone devised an approach to use one's DSLR's Histogram to
determine a basis for zone calculations? Is it at all useful?

Sure. If you see the histogram, and there is nothing below a certain point,
you can put that on whatever zone you think it should be on. You could then
count up 6 zones or so and hope to goodness nothing is above that.

It is pretty easy to do this with a spot meter, but if you have the
histogram, it just might show you something you overlooked. You would still
have to decide how important the points outside the range of the film were
essential to the image, and figure out what to do about them.

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Cheesehead wrote:
To get a conversation started ...

Has anyone devised an approach to use one's DSLR's Histogram to
determine a basis for zone calculations? Is it at all useful?

Collin
KC8TKA


If you use a spotmeter, there isn't really anything a histogram tells
you that you don't already know. If you don't have a spotmeter, the
histogram could tell you something about the range of values in the
scene, but in practice I find it hard to interpret in terms of specific
zones. Also, you would have to calibrate your large format methods,
presumably using film, against your DSLR.

I find a digital camera useful in two ways.

First, I use it to photograph a gray card under the same lighting as the
scene. I can then use this to determine appropriate RGB values for
different parts of the scene. In my photoeditor, I first set the card
to neutral gray and then measure other values. This way I can
sometimes use something as far from gray as the blue sky as a reference.
This is often helpful since I use color negative film. It would be less
helpful, but not entirely useless, for transparency film. Of course,
it is not entirely foolproof since the digital camera and film will
often respond differently.

Second, I look at the image of the LCD. I use this much as I would a
visualization filter. It helps avoid the various automatic corrections
that the eye/brain visual system makes, and so you can get a better idea
of what the final image might look like. The histogram is helpful in
getting a properly exposed digital image on the DSLR.