Exposure / zones / print grades

Bill Burk · Apr 22, 2016

That's great I never saw that before now.

OK so in The Negative, the test exposures, having been made in non-flare conditions, will result in the test negative for Zone VIII measuring about 1.30 density.

And the test negative for Zone I will measure about 0.10 density. And that is all fine and well.

But when you shoot, you will get about 0.25 density for Zone I in reality. And you will get 1.30 density for Zone VIII in reality.

Which fits the 1.05 NDR for Grade 2.

Cool. I couldn't resolve the discrepancy before this.

Bill Burk · Apr 22, 2016

Kawaiithulhu said:
This whole argument would work much better with animated visual aids versus talking a lot.
I wish I had the time right now to create something that could show the fluidity of the relationships between light metered values -> N development -> print ranges

So my recent post I was talking about flare taking you from the tests to a real picture...

Stephen estimated it as about a stop, I usually figure it as 0.4 (1 1/3 stop).

And I found you can see it happen in a spotmeter...

Stephen Benskin · Apr 23, 2016

The following three quadrant reproduction diagram shows a no flare condition. The subject luminance range is 2.10. Without flare, the illuminance range striking the film is 2.10. The exposure falls at a density of 0.10 and 1.35 for a NDR of 1.25. This is within the target range that Adams describes. But the 1.25 is too large to fall within the paper's LER range.

Bill Burk · Apr 23, 2016

To be sure, the earlier three-quad chart with flare is more likely to happen in a regular picture.

This three-quad chart without flare is what you learn and visualize when you do traditional Zone System testing. Different shots at different f/stops and shutter speeds can each make a single shot that meets the three-quad chart without flare. So you might think this is what your tests reveal.

This three-quad chart without flare also applies to the unusual pictures with a predominant tone: the proverbial black cat in a coal mine and arctic wolf in snow (for example when you place the coal on Zone II or you place the snow on Zone VIII).

But soon as you have a regular picture where some parts of the picture have a thousand times more light than the darkest parts of the picture, the darkest parts of the picture are going to get some light pollution and the earlier three-quad chart showing flare will apply.

Stephen Benskin · Apr 25, 2016

Here is a simplified example of fitting different luminance ranges on the same grade of paper.

Mainecoonmaniac · Apr 25, 2016

I wonder if you're over complicating things. But in beginning photo class, I was taught expose for shadows and develop for highlights. So assuming that if you want denser highlights, just develop your film longer. As for printing, the rule is print for the highlights and use the paper grade to adjust your shadows or dark areas. Is this not correct?

Sirius Glass · Apr 25, 2016

Mainecoonmaniac said:
I wonder if you're over complicating things. But in beginning photo class, I was taught expose for shadows and develop for highlights. So assuming that if you want denser highlights, just develop your film longer. As for printing, the rule is print for the highlights and use the paper grade to adjust your shadows or dark areas. Is this not correct?

Correct.

Mainecoonmaniac · Apr 25, 2016

Bill Burk said:
So my recent post I was talking about flare taking you from the tests to a real picture...

Stephen estimated it as about a stop, I usually figure it as 0.4 (1 1/3 stop).

And I found you can see it happen in a spotmeter...

Cool demo! I remember years ago, Fred Picker offer modifications to your spot meter where baffles are installed so flare won't like as happen. Do you know if the meter modifications work? I had a Pentax meter and never had it done.

Stephen Benskin · Apr 25, 2016

Mainecoonmaniac said:
I wonder if you're over complicating things. But in beginning photo class, I was taught expose for shadows and develop for highlights. So assuming that if you want denser highlights, just develop your film longer. As for printing, the rule is print for the highlights and use the paper grade to adjust your shadows or dark areas. Is this not correct?

It's an explanation of how to fit a scene's luminance range onto a paper grade. The simplification is it uses a fixed flare value. In actual use flare is higher with longer than normal luminance ranges and lower with shorter than normal luminance ranges.

Bill Burk · Apr 25, 2016

Mainecoonmaniac said:
Cool demo! I remember years ago, Fred Picker offer modifications to your spot meter where baffles are installed so flare won't like as happen. Do you know if the meter modifications work? I had a Pentax meter and never had it done.

Thanks,

Yes Zone VI modified spotmeters are baffled for less flare.

But I find this happens with SEI photometer, Sekonic L758-DR and the Pentax Spotmeter V in the video. The Pentax shows the effect best because you can watch it happening.

I really think it's a universal phenomenon and I don't think you really need to do anything about it.

I have a simple idea based on what I believe this demonstration supports...

If I'm evaluating shadows and have filled the meter view with the shadow area (for example by walking up close)... I'll place my shadow on Zone II.

If I'm reading a shadow and the spotmeter viewfinder looks like an average scene... I'll place my shadow on Zone III.

Stephen Benskin · Apr 25, 2016

I still think there's some blending going on. The dog had patches of dark and light hair. As the meter moved out, it took in a larger area including the lighter hairs. A better test would be to lock down the meter on something dark and move a light card into the frame. Neither test would necessarily define flare as we don't know what area the photo cell actually sees.

Bill Burk · Apr 25, 2016

Stephen's graph shows how the different N+ and N- times can be determined, by looking for how many more (or fewer) stops of Subject Luminance Range you want to accommodate. It's a pretty cool graph.

It shows flare creating a longer toe than the film really has, that is a nice thing to learn to recognize. Can you see what I'm saying?

And Stephen shows decreased exposure to make up for flare. Now that's where optimal exposure would be... but it's probably not where your exposures are really going to be if you use Zone System.

Traditional Zone System doesn't teach to decrease exposure to counteract the effect of flare. It doesn't test for it either. Not dealing with flare is one of the things that contributes towards the "half box speed" tendency of Zone System if I'm not mistaken.

So it is more likely that an actual negative will have shadow values that measure with slightly elevated density (0.25 or more) instead of a low density such as 0.10 which you "could" get in your shadows if you decrease exposure. Especially if you like shadow detail, or rate film at slightly lower speed.

Bill Burk · Apr 25, 2016

Stephen Benskin said:
I still think there's some blending going on. The dog had patches of dark and light hair. As the meter moved out, it took in a larger area including the lighter hairs. A better test would be to lock down the meter on something dark and move a light card into the frame. Neither test would necessarily define flare as we don't know what area the photo cell actually sees.

My most effective tests are an open garage door and walking towards it. Always gives me at least a stop of "flare". It's just not as interesting to look at.

Stephen Benskin · Apr 27, 2016

The example in Post #57 is consistent with what Adam's describes in the Zone System. Normal development was determined based on a given subject luminance range that will fit within a determined negative density range. If the scene is one stop larger or small, development is adjusted to fit the various ranges within the determined negative density range. Unlike the Zone System, there is a mathematical way to determine what average gradient is needed for a given luminance range and negative density range. This eliminates the need for a hit and miss method of testing and can be applied to all b&w films.

Exposure / zones / print grades

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