Exposing foggy scenes

[Dan Henderson]

I recently made some images on a very foggy morning. There were some bridge pilings in the foreground that I wanted detail in, so I placed those on Zone III. I did not record where the fog itself fell, since it was gray and gloomy and obviously low contrast. I developed the medium format film (Acros 100) in my usual brew: DiXactol single bath for 11:00 at 21 C with partial stand agitation (2 very gentle torus agitations every 2 minutes.) The negatives are very dense. To get decent shadows I have to use a #4 filter. The prints are also grainier than I like, attributable I suspect to the dense negs, perhaps accentuated by the strong filter? I'm thinking of reprinting the negative at a lower contrast grade and then burning down the shadows in hopes of reducing grain.

I'm interested in others' exposure strategies for heavy fog. Do you also place your shadows per normal Zone System procedure, or does anyone place the fog in a certain zone and let the shadows fall where they will?

 

[Pinholemaster]

I use an incident meter in fog. Let shadows and highlight fall where the my since the foggy atmosphere is the most important element in the picture.

I have a color example on my web site ( www.walterpcalahan.com ), click on the Projects nav button and look at Carroll County 13.

Overexposing will increase grain, as well as over developing.

If the fog is the most important element in the picture, it sounds like you calculated your exposure too low on the shadow side. Perhaps the pilings should have been zone 2 or even 1. Also I wouldn't increase contrast in the development of the negs, I'd like the neg be flatter. In the darkroom, add contrast with higher paper grades. Just my opinion.

 

[RalphLambrecht]

Dan

I expose fog with the Zone System just like any other scene. Trying to think about your case, Zone III on the bridge pilings, then measure the highlights to determine contrast. Let's assume an N+2 situation. This will increase the film speed (about +2/3 from normal or about box speed). Development is extended and you should get the pilings with a shadow density of about 0.35 - 0.40. The print should work on grade 2 or thereabouts, with no visible increase in grain.