Frank Doorhof
Guest
A lot of people ask me questions about freezing action like I use in my jump photography and I find out that there is a lot of unknown base knowledge on flash equiptment so I will try to make some things clear in this little tech talk.
1.
Shutter speed vs flashspeed.
When we photograph we work with two speeds together, the first is the flash duration and the second is the shutter speed.
Normally in the studio we use a shutter speed that is arround 1/80 and 1/125th of a second.
The reason is that that is the speed on which the shutter and the shuttercurtains operate, meaning going higher you will see abnomalies in the shot like one dark side.
The second is the flash duration, this is what actually makes the shot, and this is also what a lot of people don't know.
The speed of the flash (flash duration) is even often not quoted by the manufacturer. The higher the flashspeed the more you will freeze the action, the lower the more motion blur.
A lot of cheap flashes will have speeds arround 1/500 - 1/800 while topbrands will be arround 1/1500-1/3000's
Most of the time they are mentioned in two, one fast one slow.
This is normal, normally when you open up your flash the flashduration will go up, for example 1/1000's on the lowest setting it will be faster for example 1/1800's, again this is normal because a flash will vary the output by longer or shorter discharges.
2.
Playing with them.
In practice this knowledge is a superb tool.
Let's say we let a model jump and we want to freeze her in the air, we will often work with a flash unit on the lowest setting, meaning a very fast flashduration.
When we want a little bit of movement for example in the hairs or arms/feet we will raise the flash output and extending the flashduration.
Learn your flashheads and you will have gained a creative tool.
Any questions, feel free to ask.
Greetings,
Frank
1.
Shutter speed vs flashspeed.
When we photograph we work with two speeds together, the first is the flash duration and the second is the shutter speed.
Normally in the studio we use a shutter speed that is arround 1/80 and 1/125th of a second.
The reason is that that is the speed on which the shutter and the shuttercurtains operate, meaning going higher you will see abnomalies in the shot like one dark side.
The second is the flash duration, this is what actually makes the shot, and this is also what a lot of people don't know.
The speed of the flash (flash duration) is even often not quoted by the manufacturer. The higher the flashspeed the more you will freeze the action, the lower the more motion blur.
A lot of cheap flashes will have speeds arround 1/500 - 1/800 while topbrands will be arround 1/1500-1/3000's
Most of the time they are mentioned in two, one fast one slow.
This is normal, normally when you open up your flash the flashduration will go up, for example 1/1000's on the lowest setting it will be faster for example 1/1800's, again this is normal because a flash will vary the output by longer or shorter discharges.
2.
Playing with them.
In practice this knowledge is a superb tool.
Let's say we let a model jump and we want to freeze her in the air, we will often work with a flash unit on the lowest setting, meaning a very fast flashduration.
When we want a little bit of movement for example in the hairs or arms/feet we will raise the flash output and extending the flashduration.
Learn your flashheads and you will have gained a creative tool.
Any questions, feel free to ask.
Greetings,
Frank