Zone System and Graduated Neutral Density Filters

[Kevin Kehler]

As mentioned in a different thread, I am going to be doing some hiking in the Canadian Rockies this summer (hoping to go here and here). The Photographers Ephemeris indicates that when I will be there (late August), the moon will be up during the day and could be incorporated in a lot of shots. Since I plan on shooting early mornings/late evenings in order to get the golden hour light, I am concerned about excessive overexposure of the sky/mountain peaks as the sun rises/sets. The logical solution is graduated neutral density (GND) filters but I am trying to understand how to compensate for them. The majority of the film being used will be FP4+ and maybe some Tri-X.

Assuming the ground/trees/shadows are placed on III or IV (depending on the situation), the sky might read IX or X (it could be higher, who knows?) so I need to drop the highlights 1-2 zones. I would already have a yellow/orange/red filter screwed on (again, depending on the situation and desired outcome although I am concerned an orange/red filter might be too strong for early morning sunlight and blow-out highlights; thoughts?). Is this really as simple as slapping a 1-2 stop GND on the front of the filter and processing normally? I would likely be using some form of the Lee/Cokin filter system and realize I need to adjust the filter up/down to the desired location on the image.

For some reason, I think there would be a localized area of decreased contrast where the GND is and thus, I would need to increase development time to compensate. But, then I have overdeveloped the rest of the image, so I should have decreased exposure and allowed it to be slightly pushed into the desired spot. Or I could develop normally and burn in with on grade 5 in the darkroom? Or perhaps I should not use the GND since I am not shooting colour and use minus-develop to get the appropriate zones? But I am not a big fan of N-2 or more of development as I find it leaves a very difficult image to get enough contrast in the final print.

Am I over-thinking this? I think this could apply to a lot of other landscape photos scenarios as well. Thanks in advance.

 

[Bill Burk]

I think the yellow is going to move the sky down half or one Zone, the ND grad, if judiciously applied, can bring you down another Zone. But the ND itself won't reduce the contrast between different subjects within the same band of density, it will reduce the contrast between anything in the clear contrasted to anything in the gray. But you will see that.

You can count Zones just like that.

If you don't like graduated Neutral Density filters, then don't use it. You can always burn the print.

I usually disregard the high readings of sky when considering N+ and N- development, I count what's important and allow those spectral highlights to fall where they may.

 

[Maris]

There are subtleties in integrating a moon into a landscape.

A key point is that the moon disc should not be overexposed otherwise the "man in the moon" pattern burns out and the blank disc looks like an anaemic sun. I reckon the moon should be placed no higher than Zone VII or maybe VII + 1/2.

My filter kit includes grad ND filters but it also includes a grad red. The grad red boosts the contrast of the moon disc against a blue sky while the grad ND does not. Even a one degree spot-meter cannot meter the moon directly because the moon is only 1/2 a degree across but all is not lost. I spot-meter the sky right next to but not including the moon (allowing for filters, of course) and then measure the sky including the moon . When the "moon" reading is 2/3 to 1 stop above the "sky" reading then the moon will fall one Zone VII or very close. In practice I find that the time of day when all the light values fall into place, even with help from filters, is no more than a few minutes.

 

[Bill Burk]

Maris,

Always great to hear a new tip from you! Makes perfect sense.

I could always use the SEI to meter the moon since it's 1/2 degree... But using that beast takes more than a few minutes. Your tip can be used like clockwork.

 

[Kevin Kehler]

Thank you both for your responses. I think if I was shooting slide film that it would much more necessary to have the neutral density filters but shooting B&W, I might be able to get away with my normal filter set.

 

[LJH]

From AA:

"I could not find my Weston exposure meter! The situation was desperate: the low sun was trailing the edge of clouds in the west, and shadow would soon dim the white crosses. . . . I suddenly realized that I knew the luminance of the moon—250 cd/ft2. Using the Exposure Formula, I placed this value on Zone VII. . . ."

 

[cliveh]

I would have thought a polarising filter may come in handy.

 

[ROL]

Assuming the ground/trees/shadows are placed on III or IV (depending on the situation), the sky might read IX or X (it could be higher, who knows?)...

Placing shadows on III, I've almost never seen X in the mountains. If you're working in the "Golden Hours", contrast ranges will certainly be reduced in all but brightly lit clouds (one hopes for!), that's why those hours are golden for photography. I rarely need to contract more than one zone (N-1) at those times. You may however, have to make a choice when 7 or 8 zones are present in your composition (example), based on your comfort with contracting your film's development. Are the skies most important or the resolution of shadows?

I've never used a GND with B&W films (or, at all for that matter). Those decisions are made in the darkroom, where burning in skies is simply the law. Most of my time under the enlarger is taken up with skies. AA had to do it in nearly every general landscape. Filters stronger than deep yellow will almost certainly wipe out your hard fought for mid tones, particularly in low sun conditions, resulting in harsh, gritty prints (insert beaten dead horse here). Frequently, blue sky will be the same zone as the clouds, and once again a yellow filter will go a ways to reducing burning times.

It is not generally appreciated how much AA benefited from the moon's risen position in "Moonrise...", in an already darkening eastern sky in establishing sufficient contrast between the two. The rest was accomplished by his legendary darkroom prowess.


P.S. Wish I was going...

 

[Tom1956]

I wonder if "normal"exsposure on the moon is the sunny f/16 rule.

 

[Kevin Kehler]

Placing shadows on III, I've almost never seen X in the mountains. If you're working in the "Golden Hours", contrast ranges will certainly be reduced in all but brightly lit clouds (one hopes for!), that's why those hours are golden for photography. I rarely need to contract more than one zone (N-1) at those times. You may however, have to make a choice when 7 or 8 zones are present in your composition (example), based on your comfort with contracting your film's development. Are the skies most important or the resolution of shadows?

I've never used a GND with B&W films (or, at all for that matter). Those decisions are made in the darkroom, where burning in skies is simply the law. Most of my time under the enlarger is taken up with skies. AA had to do it in nearly every general landscape. Filters stronger than deep yellow will almost certainly wipe out your hard fought for mid tones, particularly in low sun conditions, resulting in harsh, gritty prints (insert beaten dead horse here). Frequently, blue sky will be the same zone as the clouds, and once again a yellow filter will go a ways to reducing burning times.

Thank you for the advice and for confirming my initial thoughts. I have a book on hikes in the area which has a number of very good photographs and while he does use a neutral density filter for almost every shot, he is also using Velvia for almost everything. I might shoot a little Velvia in 120 but they don't make it in 5x7 (yes I know I could order 8x10 from Japan and cut it down but I am not independently wealthy).

 

[DREW WILEY]

I've photographed the mtns my entire life and never once have used a ND grad filter. And they would seem to be much more of a headache
than an asset in anything related to black and white work. It's just so much easier to make such adjustments with VC paper in the darkroom.
Choice of solid color filter, however, might benefit from a bit of experimentation under analogous conditions.