This work has several new things. It is the first time I photograph an architecture project. It's a building in a monastery I already knew, which has a very strong historical framework, and which will be adapted into a hotel by an architect I deeply respect, and he is my favourite architect. So I have a footing in some way - in the sense that I'm not exploring unknown territory or searching for whatever.

A photographer always needs a territory, whether it be physical or mental. In this essay, I am quite aware of my territory: a building. This makes my life easier. But then I can't, or I won't, put too much of a narrative or documentary to it and lose spontaneity, my normal relationship with images. One of the challenges I face is to keep, in the Rachadouro Cloister, my way of looking, my instinct, and shoot without thinking whether it will make sense in the book. React intuitively and balance it with reasoning, which I take care of by studying. Recently, Eduardo Souto Moura told me in conversation that when he designed Braga's football stadium he didn't know anything about football, but he studied hard for the project. I don't know anything about architecture, but I can listen, I look, and I think.

I'm not in the building site to illustrate ideas, I don't want a photo to illustrate some idea- text is perhaps more appropriate. My challenge is to walk around the cloister, for hours, for days, photographing. It is a state of mind. Later, when editing, I can give shape to what I have done.

More than taking great photos, I want to make an essay, a fine essay. I want there to be some repetition: to feel the passage of time, to show how long it took, to mark the seasons. I want to shoot variation, because the building has really long corridors and in repetition I can show what actually changed. I want, more particularly at the end of the book, to show how Souto de Moura's project came about. That is for me personally the most important thing in this essay. I'm excited to listen to him, knowing that his interview and his words on the project will live alongside my photos. It makes me believe that this book can be a powerful way to get to know his method and to understand what he has done here. The kind of book I enjoy as a reader.

This work is also a technical challenge. I don't usually use a tripod or a photometer. The first time, in October 2018, I forgot to bring the photometer and thought I would miss some shots. I didn't miss a single one. The second time I didn't bring it on purpose. I always calculate, intuitively, from experience, each photo's exposure time. This may seem a bit irrelevant, but it's a challenge for me, because we are talking about three minutes, four-minute exposures, sometimes even six. It's demanding, because in this kind of photography I work with very large depths of field to get everything in focus. I always have the aperture at 16.22, and that counts. Normally, in my photos, time counts, and I have to be quick - in 1/125, 1/250 seconds - and only then I check the aperture. Here, the aperture comes first, and it changes everything. It's funny how in this project it's actually the space that counts, and I just wait: two, three minutes - it's new to me - but while I press the shutter, the photo is being made. It's exciting to think about photography in such a peculiar way. Three minutes with my finger on the button as the photo is being shot is something that makes me think of it differently. I can see the light change within the photo.

Shooting architecture is therefore a very different and demanding affair. It's a huge technical endeavor. And yet, it is easier, the building doesn't move, it doesn't run anywhere, it doesn't vanish. Usually, I shoot, for example, a lady running to catch a bus; if I'm not in the right place at the right time, I lose the shot. In the Rachadouro Cloister of the Alcobaça Monastery, there's time. You can even miss the shot and do it again.