Thursday, March 31, 2011

Pinhole and other Macgyvered cameras

Abe Morelle makes images by photographing the
camera obscura effect in rooms. This image is
projected on the wall by means of a pinhole.



Box
black gaff tape
tinfoil
sewing needle
sandpaper
black matt paint
film or photo paper


http://www.abelardomorell.net/


essentially, pinhole is dead easy. 
Make a box light tight and the interior black.
 Make a hole where you want to put you're aperture. 
Get a piece of tinfoil and a 
sewing needle. (sewing needles come in different gauges and as such you may select your idea aperture, the smaller pinhole and thinner surface, the sharper, and the longer the exposure). Vignetting occurs as the diameter of the hole approaches the thickness of the material in which it is punched, because the sides of the hole obstruct the light entering at anything other than 90 degrees.
Poke a hole in the tin foil with the needle. Very Gently.
Tape the tinfoil over the opening in the box making sure it is completely secured with no light leaks. 
Take a piece of the gaff tape and make a tab which will cover the aperture when not exposing, working like a shutter. The film or photo paper will go in a holder or directly inside the box adjacent to the aperture.


The math and science:
d=1.9\sqrt{f\lambda}  
where d is pinhole diameter, f is focal length (distance from pinhole to image plane) and λ is the wavelength of light.


The f-number of the camera may be calculated by dividing the distance from the pinhole to the imaging plane (the focal length) by the diameter of the pinhole. For example, a camera with a 0.02 inch (0.5 mm) diameter pinhole, and a 2 inch (50 mm) focal length would have an f-number of 2/0.02 (50/0.5), or 100 (f/100 in conventional notation).
Due to the large f-number of a pinhole camera, exposures will often encounter reciprocity failure. Once exposure time has exceeded about 1 second for film or 30 seconds for paper, one must compensate for the breakdown in linear response of the film/paper to intensity of illumination by using longer exposures.


exposure times
we were using photographic printer paper in our pinholes. 
Photographic paper has an ISO or film speed of somewhere between 4 and 10. A good way to think about this is in comparison to average film speed which is 200 or 400.  Exposure times for those average films on a sunny day or fractions of seconds, whereas when we made our exposures onto photo paper  it took much longer. The shortest exposures being 45 seconds to 4 min. depending on how much sun/shade and different camera shapes.  The light will change, especially in Edinburgh. But, it is really important to make notations of the lighting conditions, time of day, date and exposure time. This way we can make several tests before making a full exposure.

Edinburgh pinhole artist Katie Cooke http://slowlight.net  


some good links:


Next week we will be doing paper negatives and Cyannotype!

You should bring:

Images- please make photocopies/ prints on transparency of pictures you would like to print from
these should be in negative form and black and white- if you have black and white negatives larger than 35mm (120 or bigger) this will also work very well- if you are unclear about this email me as soon as possible.

We will also make photograms- bring interesting objects to arrange artistically
ex: feathers, tools, light bulbs, toy dinosaurs, teeth, fruit pieces - be creative

if you can, please continue to do work with your pinhole camera- you can purchase photo paper at many stores around town- ECA school store, Camerabase on morningside and Jacobs on Shandwick Place, are reccomendations. I would like to show you how to make your negative exposures into positive prints.

Printmaking paper - hot press Arches, is a standard - you can buy this at ECA school store

Foam or Hake brushes - which ever you prefer- get 3 total

bone folder (optional) / awl - this is for tearing paper as well as book binding.

I think i would like you all to take a look at the BB (see here) and figure out which process you would like to sign up to make a page for our class book. I have links to examples of each process. I would like each person to make a page and have  each process represented. We will need to make multipuls so that everyone in the class can have a book at the end. The sign up list is not set in stone- you will be allowed to trade if you find you really hate the process...  but i'd like a temporary list on Sunday.

Monday, March 21, 2011

Syllabus



A Crash Course in Alternative Process                                 FOREST
http://altprocess.blogspot.com                                               darkroom@theforest.org.uk

Description
Students explore and array methods for creating imagery in contemporary Alternative photography methods and practices. The aim is to open the world of super DIY image capture and printing. There will be handouts every week with technical notes on processes as well as a little history and overview of selected artists working within the medium. We cover safety and handling of chemicals, emulsion and chemical preparation, making and printing images.

 The course would include in class discussions and critique of works made in addition to demonstrations of technique and in class work. Supervised time slots could be arranged for out of class work.  I hope to curate a show as a group of the work created over the course to display in the Forest gallery or perhaps to make a class book. At the very least I would like to scan students work from each process to feature on the Forest Darkroom Flickr and document in class working time. All students will of course be credited for their works with all rights reserved.  Please tell me in advance if you would prefer not to be photographed, or to have your work documented and I will respect your wishes.

It is important to come to class on time as we will be trying to pack a lot in a short amount of time. Though I will confess I am often late. There is also a very strong likelihood there will be guest participants for selected processes, and I anticipate their addition taking up a bit more time. Assignments and notes will be updated regularly on the blog listed above.

The majority of the handouts will come from:
Alternative Photographic Processes, by Christopher James,
Delamar/Thomas Learning, 2002


Required Materials
20 pound Lab fee (to cover cost of course darkroom chemistry)
images to work with negative or otherwise
Paper to print on- arches hot press is recommended
Eye protection / lung protection
Gloves if you have latex allergies
Notebook
Binder – for handouts
Hake brushes, sponge brushes

Schedule
March 27
Week 1: Overview, handout of syllabus, links, contact, brief history with 
images, intro to pinhole physics/optics and construction, exposure and development, assignment for next week.


April 3rd
Week 2: go into paper negatives, cyanotype


April 10th
Week 3: critique, examples, demo 
Van Dyke Brown, assignment


April 17th
Week 4: critique/discussion about book project, book binding, CVD 
and spearmint oil 

May 1
Week 5: critique, examples, demo 
Albumen , Assignment

May 8
Week 6: critique, examples, demo 
Polaroid lifts/transfers/ day lab, assignment

May 15
Week 7: 
critique, examples, demo AG PLUS liquid chemistry, assignment


May 22
Week 8: exchange pages, bind our books , final critique