Joe.Recon wrote in post #15863185
Very good point, thx. Now you mention underexposing to 2 stops down, and I understand that part, now what would be a good flash speed for golf or baseball swing keeping in mind that I would shoot at sundown? 1/3000th, 1/7000th?
It's not that simple. As mentioned earlier, there are many factors. How fast is the subject moving? How close is the camera to the subject? Which direction is the subject moving in relation to the camera's sensor? Across the frame or towards the camera? Is there ambient light? How much? How much are you under exposing the ambient light by? And so on... The bottom line is, you need a strobe with a fast (or short) flash duration. If the rated duration is listed as a t.5 duration (most do to inflate the spec), divide by roughly 3. So for example, if a strobe manufacturer claims their strobe has a flash duration of 1/5000 but doesn't specify if it's t.1 or t.5, it's more than likely t.5. Therefore, divide by 3 which = 1/1666. Also remember that most strobes perform best at full power. So, as you dial the power down, your ability to freeze action decreases. The Einstein is measured and advertised as a t.1 duration and only gets better as you dial the power down.
With all that said, you just need to get out there and do it. Perhaps find a shop that rents and sells gear. And tell them that you plan on buying some location lighting equipment but aren't certain what you want yet. Most shops will let you rent and then deduct that cost from your purchase if you decide to buy it.