User manual PROFOTO ACUTE 12

[. . . ] . 10 Colour temperature . . . . . . . . . . . . . . . . . . 10 Energy Distribution . . . . . . . . . . . . . . . . . . 11 Energy control and "Bracketing" . . . . . 12 Automatic safety function . . . . . . . . . . . [. . . ] Before mains connection make sure that the voltage selectors match the mains supply voltage. Connect the unit to the mains with the cable included in the delivery. Never use ordinary household extension cords to extend the power cable. They may overheat, Contact your Profoto distributor for proper equipment. 6 READY LAMP/TEST BUTTON The ready lamp button has two functions. First, it lights up when the unit is fully recycled. Second, it can be used to manually sync the unit (open flash). When a lower energy setting is chosen, with the "Bracketing" selector, release a flash so that the unit can recycle for the new energy setting 7 SYNCHRONIZATION Synchronise by connecting the synchro cable from the camera to the synchro input. When the synchro cable is connected the built-in photocell will be disabled. FLASH HEADS Acute (AB and ABS) flash head The AB/ABS flash head is fan-cooled. Make sure that the voltage selector matches the mains supply voltage. Check also that the modelling lamp has the correct voltage. The AB flash head is delivered with the Disc reflector intended for use with an umbrella. When more advanced lighting is desired, we recommend the use of any of Profotos many accessories and reflectors all easily attached directly onto the head. The PA flash head is convection-cooled, i. e. without fan cooling, which puts a limit on the number of flashes that the lamp head can emit without overheating. The maximum output is 4800 Ws per minute which is to a 2400 Ws flash every 30 seconds or 1200 Ws flash every 15 seconds, or 600 Ws flash every 8 seconds, or 300 Ws every 4 seconds, and so on. The modelling lamp included in the delivery is a 100 Watt medium screw base lamp (E27)The AB head can also be fitted with a Halogen 150250 Watt medium screw base lamp (E27). The flash tube and the modelling lamp can be enclosed in a frosted glass cover for a closer matching of modelling light and flash illumination. The ABS flash head is delivered with the Zoom reflector, Halogen modelling lamp 150 Watt and frosted glass cover. PHOTOCELL AC 8 9 FLASHTUBE A UV-coated Quartz flash tube is included in standard PA and AB/ABS flash head deliveries. The flash tube has two metal pins for insertion into the unit. When removing a flash tube, pull it straight out of the sockets. When inserting a flash tube, check that the trigger-wire connection clasps properly around the flash tube. ALWAYS UNPLUG THE LAMP CABLE FROM THE GENERATOR BEFORE CHANGING MODELLING LAMP OR FLASH TUBE. ENERGY DISTRIBUTION The energy is divided into two groups. A and B. The energy in A can be released through ONE flash head and the energy in B can be released through ONE flash head or can be divided equally between TWO flash heads. The two groups (A and B) can be isolated or combined. The energy can be reduced to half in both groups by using the full/half switches. The total energy can additionally be reduced by using the bracketing dial (see Energy control). [. . . ] This results in three different exposures. One is "correct", one is overexposed by a 1/2 f/stop and one is underexposed by a 1/2 f/stop. There have been three different exposures without any change in lighting or depth of field. It is of course possible to choose only a 1/4 f/stop "bracketing". [. . . ]