Click on Advanced Search for a more precise search which allows any combination of the 19 selection criteria stored against each image to be successively added in to narrow down your search.
The best way to explain is by an example:-
Suppose you are looking for photographs of an English Electric Class 40 Type 4. You may want shots in a particular livery or in a selected area or at a given date.
Select BR, Diesel, Class 40 using the Company, Category and Class dropdowns and hit the GO button. This will return thumbnails of all the available Class 40 photographs.
Return to the Advanced Search to narrow these down to those in green with full yellow ends using the Livery dropdown. To further refine the selection to only those with a D-prefix number whilst in this livery go back into Advanced Search and enter D in the Loco Number box, leaving the other boxes unchanged.
You can carry on narrowing down your search, perhaps to all those photographed in the North-West, by adding in another parameter: choose North-West from the Area dropdown. To select just those taken in or around Manchester, type Manchester into the Location box.
Still not satisfied, you may want to choose by date – use either the Period box to select by decade or to look across a longer or shorter period enter the first and last date into the two Date boxes.
In all cases each new criteria you have entered is added to those you have already filled in, thus narrowing the image returned with each additional filter you add in.