Metering in overcast conditions

[mark]

It has been overcast here for several days. Truely not normal. I wanted to go take pictures, but when I got out there I had no idea how to take an exposure reading. There were no shadows to speak of and I was lucky to get an SBR of 3. Then I went home and got on the net to look to see if I could figure it out. I noticed that there are a lot of alt process photos taken in fog and what seems to be cloudy conditions. How in the world did they get a negative with the range necessary for such a shot. I am not enlarging these negs because I do not have the necessary paraphanalia to do so. I have a choice of AZO and alt processes, so i am now stumped.

Anyone have a thought?

By the way, how can people survive in conditions where it is cloudy for more than two days at a time? I need sun.

 

[Donald Miller]

I can't answer your question on the basis of alt process but I may be able to answer your question on the basis of Azo.

In flat lighting the best that one can do is to plan on developing accordingly. I have been told that a SBR of 4.5 is a virtual impossibility so I take that as informed information. There is normally more local contrast then one realizes inherent in most scenes.

Film choice, EI, and developer all enter into the equation. The films that seem to be recognized as having the best expansion capabilities are Efke PL100, Tmax 400, and Ilford FP4. The developers that seem to have the greatest ability to expand contrast are ABC Pyro, and Pyrocat (of the staining developers).

Obviously if we are planning on a low SBR development procedure then the film will be shot at a higher EI. All of these factorws contribute to building density range in a negative.

The other thing that I think worth mentioning is that low contrast scenes are low contrast scenes. One does not take a foggy scene and expect to portray it as brightly lit and high contrast. That is where the long scale of the materials that you mention come into play...they are able to portray a palette of tonal variances unlike a silver enlarging paper.

 

[clay]

FWIW, SBR of five is theoretically the lowest possible, since a perfectly lit subject with shadow reading = highlight reading will still have local contrast variations of about 5 stops.

Here is the bonehead method of taking a photo under flat lighting with an incident meter when you are targeting the neg for alt process work or Azo. Say you have HP5, which nominally has a rating of 400. Go ahead and rate it at 400 since you are going to be developing the heck out of it. Double the 400 EI to 800 and plug that in your incident meter. Point the meter at the sky and get your exposure reading. Expose the photo and then develop it to the highest CI you can muster. Pyrocat HD 1:1:50 for 16 minutes will probably get you there. This will give a you negative that reasonably represents the scene in front of you in a way that will print well on pt/pd or azo.

 

[mark]

At this point in my photography bone head pretty much sums it up. I botched four negs in my last development. Scratched the hell out of them.

Thanks folks. If it is cloudy this weekend I will give it a shot.

 

[Aggie]

Well Mark Rain seems to follow me when I travel. Guess we will get some in Page this weekend.

 

[mark]

Really? I never trust the weather. We were supposed to get rain here every day this week. Totally cleared up today. For all I know it will snow tomorrow. Have a safe trip and I will see you in Page.

 

[Ole]

FWIW, SBR of five is theoretically the lowest possible, since a perfectly lit subject with shadow reading = highlight reading will still have local contrast variations of about 5 stops.

Wouldn't that depend on the local contrast? If the subject is as flat as the light, I would think you can get close to SBR=0 (which wouldn't be an interesting subject, but anyhow)?


On the (side)subject of weather, I can say from personal experience that after five months of continuous rain, you really appreciate a glimpse of the sun. Those of you in the sunnier climes have no idea of what sunlight is!

 

[mark]

Ole

You would be surprised at how much we in the desert southwest USA rely on the sun.

one month of rain would have ended my stay in what ever country or Climate I was in. I must have sun. There are no ifs ands or buts.

I guess you feel the same about sun as we do about our monsoon season. Rain in the desert after a drought is a sexual experience. But maybe that is just me.

 

[Aggie]

You want Sun? California has plenty of Damn sun. only a few months of the year are there any whispers of clouds for stomrs. The rest of the year it is day after day of boring glaring sun that is harsh and just plain flat. You scramble for those early moring and later afternoon evening times when the light will not be as harsh.

I lived in tucson for several years. I remember the monsoons, where the wind went one way and the rain came down so hard it was going in 180 degrees the opposite direction. then there was the dry rain, where it would evaporate before it hit the ground. No way do I want to live in that heat again. Give me a place where it is under 100 degrees in October.

Personally I think the light when it is overcast gives a magical glow. Look at your hand in bright sun light and when given the chance on an overcast day. The skin will glow and be more detailed when it is overcast. This doesn't mean I want the sun to be hidden all the time, I just like variation not 8 to 10 months of the year of not a cloud in the sky.

 

[noseoil]

If wind permits, you might consider a very slow film for its inherent contrast. A film with a steep curve will be a good bet to begin with. Extended development with a 1 stop push is as good as it gets.

 

[Jorge]

Then again there is nothing wrong with images that do not have absolute blacks. In alt printing we take advantage of the good separation of light tones, meter for the light tones and let the dark tones fall where they may.

So then you have two approaches, you can "force" the contrast by trying to expand the contrast in the film or you can meter for the highlights and let the dark tones fall in middle gray. In each situation you will have an image that will have a very different feeling.
It all depends what you want to communicate in the print.