ILFORD MICROPHEN is a fine grain film developer which gives an effective increase in film speed. A speed increase of up to half a stop can be achieved with most films but with faster films such as HP5 Plus, Delta 400 Professional and Delta 3200 Professional it is more. Many developers that give an increase in film speed usually produce a corresponding increase in grain size, MICROPHEN is formulated to overcome this disadvantage, low alkalinity of the developer reduces grain size and grain clumping. Therefore MICROPHEN is said to have a high speed/grain ratio, i.e. it gives a speed increase while retaining much of the grain characteristics associated with fine grain developers.