Immateriality of digital image

It is a fact that the digital image has a state in which it is pure information. That is the case when it is written as a file, as sequence of bits. But once printed in paper, it is no less physical or material than the traditional analog photography. Similarities are not only in this final output...

Focal length and image circle

(image source: wikimedia commmons) You certainly saw already a diagram more or less like this one. It is a standard way to explain what focal length is. This is how camera makers talk about focal length and they have a good reason for that: they want you to learn what focal length means in the...

Popular portrait, at peace with fantasy

It allows plenty of good insights the exhibition, Retrato Popular, do vernáculo ao espetáculo, (Popular Portrait, from vernacular to spectacle) on show at SESC Belenzinho – São Paulo, since May 6 and ending July 31, 2016. First by providing an encounter of popular art, that is made for...

Measuring lens aperture

Article explains a method for evaluating lens aperture without dismantling the lens. It can be also the basis for calculating diaphragm diameters for Waterhouse stops according to a desired apertures scale.

Ground Glass – do it yourself

If you ever gave up about a camera because of missing or broken ground-glass you will regret about it after reading this post. It is very easy to produce a high quality ground-glass for replacement or for a new project for a large-format camera. Nowadays when old processes, old lenses and cameras...

Flash powder, light a lot with just a little

Everyone has seen a photographer, in movies, burning something that seems to make more smoke than light. That was the flash powder. It consists of a metal part and an oxidant. A mixture that resembles gunpowder. This was used for photography from its very first decades up to nearly mid of the...

What is a photographic lens?

Any scene you can shoot is made up of objects that emit light (own or reflected) and it is from this light that the lens will form an image to be recorded on film or digital sensor. If it were possible to block almost all light coming from a scene, like this one from my apartment window, leaving...

Light and colors, physics and perception

Yes, light is a wave, and then … Wave, is a phenomenon in which there is energy transmission without transport of matter. It’s like energy traveling in space. It is easier to understand if we think of an example where there is matter transporting energy. For example, to drop a stack of...

Photographing birds flying

The practice that I will describe is the one that allowed me to take some reasonable pictures of seagulls in Hamburg harbor in Germany in 2008. Later, in other occasions, it served me again and I lost less time to catch some images birds flying. That is the case, to my level of requirements, of...

What is a histogram in photography?

  With digital cameras is always good the possibility of checking the result right after the click. Those who never used film don’t know how good it is. But sometimes, a quick evaluation may show that the picture registered is OK and later, on the computer, we realise that shooting it...

Considering a darkroom? 1st part: The Camera

If you consider adding some chemistry to your photography, but are uncertain about the difficulties in setting up a darkroom in terms of time, work and money… then this post is for you. The idea is exactly to reflect upon ways and alternatives to leave for a while the digital. I say...

Adjusting sharpness

The intention in this post is to explain what softwares for image editing do when you adjust sharpness of an image. Sharpning in a great many of contemporary  photos, done and retouched digitally, has turned into a sort of convention and photographers may feel like missing the party if they do not...