Press Information, released by broncolor, article No. 2-3115/09_dr dated: October 2009
Have you already had to ascertain that despite the supposed 1/12’000 s flash duration, the arms and legs of a model were still blurred in the picture? – even when purchasing a flash unit, it is very important to read the small print; some data is not even mentioned by several manufacturers.
When comparing the technical data of the flash duration, it is important to ensure that the t 0.1 values (total flash duration) are compared. Only these values provide a reliable guide to obtain the expected picture sharpness. (If t 0.5 flash durations are compared, it is important to know that after this period, still 50% of the flash power is produced after t 0.5 has been reached. This can greatly influence the lighting and picture sharpness). The second half of the discharge requires twice as long as the first 50% of the flash, compared with t 0.5.
When comparing the technical data of various manufacturers, ISO Standard 2827 must be observed which defines two values for quoting flash duration:
- 1.) The effective flash duration t 0.5 is defined as being the period during which the flash intensity exceeds 50% of its maximum. 50% of the flash power is produced after t 0.5 has been reached.
- 2.) The total flash duration t 0.1 is defined as being the period during which the flash intensity exceeds 10% of its maximum.
- 3.) The effective flash duration t 0.5 is the most common one and is normally indicated in data sheets and brochures. However, when the task is to “freeze” motion with short flashes, it needs to be considered that after the stated time t 0.5, the flash still discharges half its intensity. Therefore, in respect of attainable sharpness, t 0.5 cannot be compared with shutter speeds of the same duration.
The new broncolor power pack Scoro A calculates in mode t 0.1 (min) the shortest possible flash duration of each selected flash output. This is 1/8’000 s (t 0.1) for all Scoro units. The flash duration can be deliberately extended (up to 1/85 s) in order to gain specific movement effects.
If you would like to flash fast-moving sequences, we recommend that you contact your distributor or rental station to make enquiries about the shortest total flash duration t 0.1, or make a comparison with practical shootings of a moving object.
Related Article: //photonicsenterprise.com/trail-secret-short-flash-duration/
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