With this assignment, students will explore lowlight/night photography or daytime long exposures using Neutral Density Filters .
Part A: Shooting
Students will be experimenting a lot with various exposures. Failure is to be expected, but also hopeful surprises. Students will be asked to photograph long exposure scenes with existing light whether during the day or night. Take your time.
One challenge of long exposures is the failure of Reciprocity. When a film gets exposed to low levels of light that require a long exposure, the sensitivity of the film drops. For example, through the meter, or on paper, you may determine an exposure setting, but following that setting may result in an underexposed negative. It this case, you would need to add additional exposure beyond what you and your camera have determined. This phenomenon, commonly known as Reciprocity Failure, varies between different film stocks. Below is a chart from the Ilford website, but this should only be considered advice and may or may not give the best results for a particular image and lighting scenario. Students may want to bracket their shots to ensure a good printing negative.
Part B: Processing the film
After students have shot their rolls of long exposure images, they will need to process their film. Because of the potential exposure challenges of night photography and the possibility of high contrast situations (where street lights may be involved), students may want to consider and alternative processing technique for their film. Using higher dilutions of their developer along with longer development times could yield a better negative for printing. These processing techniques may be a good idea for daytime long exposures as well in case of over exposure. A class discussion will cover these options.
Due in Class
For class critique, students need to bring in their proof sheet(s) and one enlargement. This assignment will be due on March 27th.
Some helpful tips below.
Metering for a night photo is a challenge. Many times your light meters in your camera will not even register a setting. One thing that you can try to figure out your Measured exposure (before Reciprocity Failure) is to set your camera to ISO 1600 or 3200 (depending on how far your camera goes) and set your lens to its widest aperture. See if you get any sort of reading. If you do, use your knowledge of equivalent exposures to figure out what your meter would say if set to your given ISO for your film.
For example, if you are able to set your camera to ISO 3200 and at f/2.0 you were able to measure a meter reading at one second, you can extrapolate your exposure using equivalent exposures:
ISO 3200 f/2.0 @ 1 second
ISO 1600 f/2.0 @ 2 seconds
ISO 800 f/2.0 @ 4 seconds
ISO 400 f/2.0 @ 8 seconds
ISO 400 f/2.8 @ 16 seconds
ISO 400 f/4.0 @ 32 seconds
So, as you can see from the chart above, we were able to determine a measured exposure of f/4 @ 32 seconds for our hypothetical night scene. My recommendation to you is to take that image, and then do at least two more frames with more exposure. Use the chart below and/or use a google search to help you determine additional exposure times compensating for any Reciprocity Failure. You can also use a digital camera to help determine your night scene exposure, but remember that digital doesn’t suffer from Reciprocity Failure like film, so make sure you add exposure time to your film images.
Basic Reciprocity Chart: