When we see the first photographs of the Kodak Brownie, that camera from 1888, we are surprised because they are round. It is a unique format that has not been seen practically since then. Now all photographs are rectangular or square, when the projection is circular. The solution to this dilemma is simple, but it has many answers that we are going to discover below.
You may never have asked yourself this, but if you are a bit observant and know the history of the medium, you will see that, in principle, the projection of light on the sensor is completely circular. The photographs should look like the first ones taken with the famous Kodak Brownie, one of the most original cameras in history, the same one used in his childhood by the famous photographer of happiness: Jacques Henri Lartigue.
Thanks to his first works, we know in depth the advantages and virtues of the circular format and its problems, which has led us to explain why we no longer see any camera that allows shooting in such a format, which would be the most natural.
Why don’t the photographs have a circular format?
The light falls on the sensor by a conical projection. To collect all the information, the sensor should be round. But it is not like that, the image is always (we will clarify) is rectangular. The easiest answer is that since the sensor is rectangular, it is its own mask, there is no other way to do it.
It can also be by pure tradition, since throughout the history of art paintings are rectangular, but it is a statement that falls under its own weight. The portrait, one of the great themes, could be painted round, the tondi of classical Antiquity that came back into fashion in the Renaissance, such as the ‘Tondo Doni’ of the first Michelangelo.
So this explanation is also invalid. Another option is that the film, being on a roll, takes advantage of more information if it is in rectangular format. But again it doesn’t work, because the Kodak Brownie, the first camera to be sold preloaded in 1888, gave you the opportunity to shoot 100 frames in circular formatas we have mentioned before.
The explanation is much simpler and we have it right under our noses, when we look at our photographs and we obsessed over center-to-corner sharpness, when we want to see the center of the image the same as the corners of the paper. And we see that it is not.
The simplest explanation to understand this little gibberish
In fact, from a strictly photographic point of view, it would be great if the projected image were completely circular. In this way, we could choose the proportion and orientation of the photograph at the time of editing, taking advantage of the greater amount of information, even more than if it were square, since we would have a larger surface to choose from.
But it is not possible. All It is due to an issue of optical design and another economic. If these two problems that we are going to see next could be overcome, we would be making round photographs.
In the latest and sharpest lenses on the market, the highest quality, in terms of sharpness and luminosity, occurs in the central area of the plane. Corners always suffer from loss of sharpness and brightness. And it all depends on the coverage of the lens, which is the image that is projected, in the form of a circle, on the sensitive surface of the sensor.
The coverage always has to be of a diameter greater than the diagonal of the sensor. Why? To avoid the loss of quality that we have mentioned. If you notice, the corners always suffer from vignetting and less quality. By eliminating the image that forms on the circumference, we gain in overall quality. But we can’t avoid corners…
This is one of the reasons. The other is due to sheer economics. If they made bigger targets to take advantage of coverage, we would pay more. If they designed perfect lenses for a circular image, the additional cost would be excessive and the objectives more unattainable for most users.
Can we choose the format of our images?
Right now, with digital technology, we have all the freedom to choose the format that our photographs need. You just have to go to the Crop tool of any application or program to get it. To achieve a round image, it is a bit more complicated.
You have to use the elliptical marquee tool (or similar), configure it so that it cuts us a perfect circle (in Photoshop we only have to check Style> Fixed aspect ratio> 1:1) and we already have what we are looking for.
Then you have to go to the Select> Invert menu to delete everything we don’t need. Y save the photo in PNG format to allow transparency in networks. If we want to print, we must have the permission of the laboratory to cut the paper in that proportion.
Another option would be to buy a extreme fisheye lens, to directly get the format we are looking for. They offer such an angle of view that it does not take advantage of the entire diagonal of the sensor. For this reason, everything would be deformed with a cartoon aspect due to the strong distortion it causes, so we do not recommend it, except in extreme cases where we want to see the curved horizon.
It is a pity that it is not easier to choose this format. In chemical times it can be understood, but today it is relatively easy, as we have seen. It is another option and I assure you that it has many possibilities.