Thanks to my many years of professional experience, I can very quickly distinguish between interesting and uninteresting subjects. Even so, there is always the risk of making the wrong decision—for example, driving past a beautiful yurt in the hope that an equally beautiful one will appear farther on, but with more goats standing in front of it. And if I'm unlucky, the next yurt has fewer goats instead of more—or plenty of goats, but the yurt is covered with plastic tarps instead of felt. Over the years, however, I have developed quite a good intuition, so I sometimes turn back after a few minutes after all to photograph the first yurt. This instinct is especially valuable in regions I am visiting for the first time, where I don't know what still lies ahead. A local driver or guide is no help in that regard, because they can't know exactly what matters to me.

Over the decades, I have naturally become more demanding. In the early years, despite the high cost of film, I ultimately took far too many photographs because everything was new and exotic to me. Today I no longer get off my motorcycle or out of the car for every camel, because I already have so many beautiful camel photos in my archive. Instead, I focus specifically on subjects that are new or simply promise even better images. Today I know exactly which particular subject I'm still missing and want to capture. Of course, that can also lead to frustration, because you find what you're looking for less often.

These days there are often entire days when I don't press the shutter even once because I can't find a truly good subject—or simply because the weather isn't ideal. Rather than photograph for its own sake or out of boredom, I'd rather not photograph at all, and rather than take bad pictures, I'd rather take none. That has two sides: on the one hand, my images benefit from my having become more discerning; on the other, I've become hardened and am less easily excited, so I have to keep motivating myself. But that's true in every profession. After twenty years in the bakery, a baker will also be much more enthusiastic about baking a newly created pastry than the pretzel they've been making since their apprenticeship.

The enthusiasm and curiosity of those early years did have their advantages, though. Nowadays I sometimes miss the chance for an extraordinary picture because I think, “Oh, I've already got that,” and stay sitting in the car. If the situation then develops into something truly special, it's often too late.

At the beginning of a trip, I do have a rough idea of the subjects I want to photograph, but not a checklist that I tick off point by point. I look around and simply let the city, the landscape, festivals, or other situations inspire me. But whether I'm driving or walking through a village, the camera is always with me—in the camera backpack on the motorcycle, on the back seat of the car, or in the camera backpack on my back.

So as not to frighten the locals, who are always potential subjects, I never drive right up to a tent or yurt. Instead, I park the motorcycle, car, snowmobile, or whatever vehicle I'm using some distance away and approach on foot—and of course I take off my helmet and sunglasses if necessary so people can see my face. Nor do I grab a tripod, cameras, a huge telephoto lens, drone, and so on and set off laden like a Christmas tree. Instead, I first approach people either completely empty-handed or, less often, with just one camera slung over my shoulder, establish contact, and then, if the conversation develops well, eventually ask whether I may take photographs.

That naturally means I have to walk back to fetch what I need: the camera, or in the past, when I worked with different ones, perhaps another camera, the appropriate lens, a tripod—whatever is required. Sometimes I wish I had an assistant I could send to get everything. But I can't afford that as well, because in many regions I already have to hire a guide and/or interpreter. As long as I traveled through the Sahara and the deserts of Africa, I managed reasonably well with the former “colonial languages,” today's lingua francas, English and French. But the farther my travels took me, the more often my language skills reached their limits.

When something catches my attention, I have to distinguish: Is the subject already there? If so, is it fleeting or permanent? Or could something become a subject? The best case, of course, is when the subject is already there and will remain. Take a beautiful sunflower or an unusual rock formation—neither can run away. Then I can take my time, calmly view the subject from different angles and distances, and, if necessary, wait for better lighting conditions. If the subject is already there but fleeting, such as a volcanic eruption or the northern lights, then of course I have to react immediately.

In principle, people and animals are also “fleeting” subjects in the sense that they move. I don't just mean that my subject can stand up and walk away, but also, for example, that facial expressions change. At the same time, depending on the situation, they may only become a subject. If I see a cheetah in the Masai Mara or the Serengeti and a herd of gazelles in the distance, it may be worth waiting to see whether the cheetah decides to hunt a gazelle. In short, the decision is this: Do I have to be quick, can I take my time, or—and for me, as an impatient person, this is the hardest of all—do I have to wait?