Fotografia

About pinhole photography.
The pinhole camera is proof positive that fundamental principles do not change. Euclid demonstrated the image-forming possibilities of the pinhole in 300 B.C. In the 16th century, Leonardo da Vinci is credited with giving a description of the pinhole camera more or less as we think of it today.
There are, when it comes to making photographs with what amounts to nomore than a box and a hole, more than a few sceptics and honest doubters who, from lack of actual participation dismiss pinhole cameras as a mere novelty.
A pinhole camera is easy to build. The camera can be made from almost anything. From oatmeal tins and boxes to made from scratch cameras of wood or sturdy cardboard. There are several places such as the Pinhole Resource in Santa Fe where you canbuy cameras made of wood or kits.
As a teaching device
Pinhole photography provides an inexpensive means to introduce people of all ages to the principles of photography. It's a hands-on experience where people learn by doing rather than listening to long theories and less than inspiring explanations. Pinhole photography is about making mistakes and learning from them.
How does a pinhole work?First the dull stuff...for anyone who has studied photography and optics the theory of image formation is (or should be) well known...but, there are a few million people out there who aren't aware of the difference in this theory between pinholes and lenses...sounds about right, after all it's not the sort of thing one talks about over breakfast, is it?!
Ok...we see things because light raysreflect off of them and these reflected rays form an image on the retina. A camera is a mechanical eye, so it might be useful to think of it in these terms; we use the term 'ray' of light when we talk about using lenses to form an image. We use the term 'beam' of light when we talk about making images with a pinhole. The difference is one of dimension. A ray of light is defined as a line of light,while a beam of light is defined as a bundle of parallel rays.
Onward...
Light falling on an object reflects off in all directions. When a lens is used to make an image rays from the same point on the object are reflected to its surface, this forms a cone of light. As the rays pass through the lens they are bent or refracted and as they are made to to disperse, they are again formed into a cone,the diminishing end of which is the point of focus...got that?
right...
Consider this...a photograph is really composed of points of light that vary in size. If the points are too large the image will not be sharp.
Getting to the point...
Pinhole images are formed by a beam of light, the diameter of which governs its sharpness. The diameter of the beam is determined by the diameter of thepinhole...so, a really big pinhole will make a less sharp image and a very small pinhole will make a very sharp; but not as sharp as a lens, image...easy!...right?
This is all very nice, but what does it mean?
Glad you asked. What it means is that pinhole images aren't as sharp as images made with a lens, and that the size of the pinhole will determine how soft or sharp your images are...as well asdetermining the time you'll need to expose the film or paper for...better have a look here for more info on that...
What I think of pinhole photography, by Dave Clarridge
It seems that most of what is written, and discussed, about photography centers on optics, film speeds and curves, the latest and greatest equipment, zone systems........ All valid issues which, to me, miss the real point of itall. What I love about photography is that it is magical. Today I still get that funny feeling that came over me the first time I saw an image come up in the developer.
What I love about pinhole photography is that it is MAGICAL. Without all the expensive gadgetry I am able to capture what I feel, more than what I see. One never knows exactly what you're going to get with a pinhole camera until...