The Visatec DFM is a digital incident flash meter with an exceptionally large measuring range of more than 14-2/3 stops. The DFM is well-suited for measurements of low capacity flash units used by amateur photographers as well as for very high capacity studio flash equipment. The 1/3 f/stop increments on the DFM meter are easily readable on the large digital display. The measuring speed of the meter is a fixed 1/60th of a second. However, any ambient light present is also included in the flash measurement. When the unit is put into MULTI LOW or MULTI HIGH, any number of flashes of different intensity may be measured. The memory of the DFM will record each input of light and indicate the accumulation value on the display. There is a HIGH and LOW range of measurement which overlap by two f/stops. The horizontal lines on the display next to the number indicate either a 1/3 or 2/3 stop difference.