There are several ways to search the archive; you can browse through the newest photos on the front page; you can click on the category you are looking for in the drop-down menus, and if you found one image, you can find similar images by clicking on the tags.
But the most precise way is using the search function; it searches tags, categories and photo titles, and the best result you get by combining the name of a category with some tags. For example will a search for “square autumn steps low contrast” find all photos of squares in autumn, with steps on them and without sharp shadows. “Copenhagen water edges people” will find all photos that are in the category “water edges” with the tags “copenhagen” and “people”.
All categories are in plural, so it helps typing “streets” and not “street”.
Good tags to use:
people/empty/cars/carfree – for empty or populated images
sunny/low contrast/twilight/night – for time of day
blue sky/grey sky/rain/snow – for weather
summer/autumn/spring/winter – for time of year
copenhagen/new york/hamburg/vienna/basel/lima – for location
basketball/eating/shopping/skating/walking/biking/urban sports – for activities
café/installation/bench/fountain/bush/tree/canal/bike parking – for elements
wood/asphalt/rubber/sand/gravel/pavement/natural stone/metal – for materials
squares/streets/paths/water edges/parks/gardens/courtyards/bridges/stairs/edgezones/pocket spaces/playgrounds/sport fields – for types