This is a complicated and often debated question that many experts have tried to answer. Michael Freeman, John Szarkowski, Stephen Shore, Eduardo Momeñe, Rosa Olivares, Joan Fontcuberta, Tino Soriano, and many others have put forward their views on the subject. Based on what I have read and heard, I dare to make a proposal that expands on something I wrote a few years ago.

1.- Propose an intelligent composition. This is undoubtedly an essential aspect that will determine whether the image works better or worse and whether it is attractive to the observer. Although determining what is a good composition might seem subjective, it is one of the most common aspects and the one on which there is the greatest consensus. However, there are compositions that work very well when they seem to break these rules because there are so many factors involved in a composition that it is almost impossible to capture them in a handful of rules. It's not that the image that works doesn't follow any rules, it's that there are so many that many of them have yet to be discovered.

Photography by Alex Webb

2. Provoke a reaction.

The image must have something that makes a visual impact and attracts the attention, if not of everyone, at least of a high percentage of viewers. Here the rules are less clear, and sometimes there are images that are so calculated to create that attraction that they are too obvious and turn away the intelligent viewer.

Photography by Pentii Sammallahti

3. It excites the viewer.

The reaction can be cognitive because it presents us with a kind of visual dilemma that we try to solve. But, above all, it provokes an emotional reaction that pinches us to the core. This is a difficult aspect to achieve through composition, the interplay between figure and background, and the deep content of the image. An ideal photo should provoke what Roland

Barthes called "punctum", an intense emotion that grips and shakes the viewer. Looking at many good images we feel that pinch without being aware of which detail of the image it is that moves us, and it is often a matter of unconscious associations created by the photo with an important affective resonance in our intimate world. It may be the memory of a situation experienced in the past, a gesture that reminds us of a significant person, an atmosphere that takes us back to our childhood, etc.

Photography by Tiago Santana

4. It arouses curiosity.

Sometimes we find an element of ambiguity, uncertainty, or even contradiction that arouses the viewer's curiosity about the meaning or the result of the scene depicted. Sometimes, these are figures that escape from the frame, or that overlap, hiding something that seems important, but in other cases, it is the lack of focus or the trepidation that introduces ambiguity. Sometimes, even though the figures are complete, the sharpness is total and the action has been completed, there may be something in the scene or in its protagonists that generates a certain ambiguity in the observer and arouses his curiosity.

Photography by Robert Frank

5. It transcends the direct visual experience.

This is perhaps one of the most interesting aspects and refers to the capacity that a good snapshot can have to generate ideas from the visual experience it offers us. A particular photograph can lead the viewer to find some theme or detail that is not explicit at first glance, but which emerges through the association of ideas. In short, it has several layers that offer more than one reading.

Photography by Saul Leiter

6. It is situated in the realm of photography.

Photography is contemporary, and inseparable from the cultural experience of the whole world, so in some way, it must have links with all the images that make up our visual universe. Although it might seem that this implies a loss of originality, it is necessary for the creator who wants to produce good photographs to start from the knowledge of the images offered by other photographers (or visual artists, filmmakers, etc.), so that he can place his work in a certain visual and cultural context. This means starting from certain referents in order to be able to transcend them. How far we can transcend them is a matter for discussion.

Photography by Brassai

7. It does not imitate.

Every art form has its own form of expression, so good photography should not imitate other art forms. It should explore and exploit its own medium, which means having a clear idea of what photography excels at: the documentary spontaneity of the moment captured, the veil, differential focus, motion blur, reflections, or shadows.

Photography by Josef Koudelka

8. It is intentional.

Although chance always plays an important role in creation, we often consider random what is in fact intuitive and rooted in the photographer's experience and mastery. When authorship is evident in the image, which effectively conveys the idea or message that the photographer intended, it is very likely to be a good image. Without good technical mastery, it is very difficult for the author to capture an intention in a photograph.

Photography by Sergio Larrain

9. It is creative.

Some images have originality and freshness that surprise the observer with their boldness. However, originality is not always synonymous with creativity, as it is necessary for this departure from the beaten track to be positively valued. And this ability to give the label of creativity to a photograph is probably the most subjective and complicated aspect of the aesthetic assessment or judgment, which is why it requires daring experts with well-trained criteria. When John Szarkowski highlighted the work of photographers such as Diane Arbus, Lee Friedlander, Joel Meyerowitz, and Garry Winogrand, he gave a decisive boost to the development of photography. A good example that leads me to think that for there to be creative photographers there must be good curators.

Photography by Henry Cartier-Bresson

10. It fulfills its function.

The objective that the photographer set himself or herself determined intentionality that guided the use of certain technical resources. There are photos that serve to illustrate a text or accompany a news item, or that are hung in a gallery or museum, used as postcards, included in a project or series, or printed on a T-shirt. It is therefore difficult to determine the quality of a photograph without taking into account the function it serves.

Photography by Imogen Cunningham