Double exposure or other techniques for controlling high contrast scenes?

[rdenney]

Pre exposing film will get it off the toe of the response curve, improving shadow detail and leaving the highlights relatively unaffected.

That's called flashing, and as I learned one exposes to a gray card to about Zone 1 with their expected film and development technique.

Rick "who'd be tempted to have an associate fire a big potato-masher flash on the front of that church during the exposure" Denney

[E. von Hoegh]

Right. But my point is, it doesn't neccesarily reduce contrast, and I've never noticed it improve highlight detail - more the contrary.

E. "who likes uncoated lenses for this reason" von Hoegh

[dperez]

I have done this with color film. Portra 400 and once with Fuji Provia 100. I normally make my first shot just after sunset, and then I wait another 30 minutes to an hour, and make the second exposure. My first exposure is normally slightly underexposed.

The problem that I have found is that you might get a small amount of film movement in between exposures. As mentioned in another thread in this forum, you might want to load the film into your camera back, pull the slide and let the film acclimate itself for 5-10 minutes, then start your double exposure (Obviously, make sure the shutter is closed).

[Zaitz]

Fantastic photo dperez. How are you going about metering the separate exposures?

[michaelstein1980]

I would suggest you have a look at these pictures: http://print24.com/blog/2012/04/anal...uble-exposure/

[dperez]

I normally time my first exposure till just after sunset. At that time there is plenty of light and also good color in the sky (Don't wait too long, I normally make that first shot within five minutes after sunset). I calculate the exposure for the primary subject. Since the sun has fallen, you should be able to get the shot without any highlight problems. The last time I was doing a double exposure I was photographing a building, so I exposed for the building, taking my meter reading right off of its concrete walls. I might have slightly underexposed the first shot.

For the second exposure I waited about an hour or so. I wanted the sky to be as dark as possible. I took another reading off of the building and made the second exposure. I think it was somewhere in the 2-4 minute range. I've been using color films with good reciprocity characteristics (Provia, Portra 400) so there isn't a lot of time added. You don't have to worry so much about the second exposure, because in the 2-4 minute range if you're off a little it won't really make a huge difference. If the building (or primary subject) has a lot of lights on it at night then you might want to take some time off the second exposure.

Scout out the subject before making your picture. Observe the lighting situation at night so you will know whether the subject is lit up substantially or not. Exterior lighting hitting the sides of a subject (like a building) seems to have more of an effect than lighting coming from inside the subject (windows).

Another thing I have found... If you have a scene with a busy street in your foreground, use a two stop ND grad filter, as during the second exposure there will be enough light coming from cars to over-expose that portion of the scene.

The key thing is to experiment. It might not work perfectly the first time out, but I think that you will find that you have some room to operate here. Don't forget about film movement. Acclimate the film for a few minutes before making your exposures. Even better would be to use a vacuum back film holder.

Good luck,

-DP


This building has a lot of light on it at night, so my second exposure wasn't as long as others I have done.


This required more time than the image above for the second exposure. The street ended up being a problem, as the passing cars provide enough light to over-expose the bottom portion of the picture.


I like to make my first exposure right after sunset in order to capture brilliant colors in the sky.

[Jay DeFehr]

I'm quite familiar with Diafine, thank you. I've used it for many decades. In fact I have a box sitting here on the desk.

Quoting the instructions:
"... agitate very gently for the first 5 seconds and for 5 seconds at 1 minute intervals." (boldface original)

Perhaps you should read my earlier text that you quoted:
"Constant agitation defeats the compensating mechanism,
which is to allow the developer to exhaust completely in dense areas of the negative."

Maybe Sandy knows something that the manufacturer does not know.

- Leigh

Leigh, you're such a charmer! But I agree, compensation relies on regional exhaustion/neutralization (two different things), which are promoted by rest periods in development. For maximum compensation, agitation should be the minimum required to prevent development defects like streaking, mottling, edge density, etc. With some developers, like Obsidian Aqua, too little agitation also risks excessive edge effects, which rely on the same exhaustion/ neutralization mechanism on a local scale.

[Lynn Jones]

Flickr,
You might consider Ansel's pre exposure technique with normal exposure and normal development. This give's 150% to 250% increase in density and detail in Z1 and Z2.

Set your camera lens at infinity, put a grey card fairly close to the lens so that it completely covers the film, read a reflected light exposure and decrease the exposure by 3 f stops. Then shoot your dusk photos with normal development and try that.

Lynn

[Joseph Dickerson]

Hi,

Diafine does work with rotary processing, you just need to dilute it 1:1. I use 2500 series JOBO reels and a CPE2 processor. There was a long thread on the forum some time ago started by Sandy King that dealt with this issue. Search in the darkroom, film, processing forum. I believe Sandy is the expert on Diafine/rotary processing. You could also try "The Unblinking Eye". Lots of info, much of it by Sandy.

JD

[rlee2010]

You can make building and street lights appear to be on or more prominent by making an exposure before sunset and another one at night,