Shutter speed and flash - can someone help me understand the relationship?

I'm trying to understand a concept I'm having trouble with - I wondered if someone could guide me through this?

Lets say we have a controlled environment of a studio lit with strobes. Taking a light reading of ISO 100, 1/200th and say, F8 and setting my camera to that.

If I then change the shutter speed to 1/160th or 1/100th, with no other changes, what should I expect to see and what should I look for?

In non flash situations, I'd expect the shot to be a little more over exposed, perhaps even starting to blur - but with flash, would that be the same? Wouldn't the flash freeze the subject?

Under what situations would you change your shutter speed from the max, when you have plenty of light?

I guess there are a couple of questions there

My studio is in boxes right now, or I'd test and experiment!

Easy,,in a controlled environment like a studio shutterspeed has very little (or no) impact on exposure.. Lens aperture controls exposure..

Unless you've got very high ambient light levels the shutter speed (assuming it's slower than sync speed) is, within reason, irrelevant. If you slow the shutter speed 5-6 stops (in normal conditions), the ambient light may begin to make itself known. The darker the ambient light, the less difference shutter speed makes.

Thanks Jurgen - that was where my gut was leading me (obviously, within reason ... a 5s exposure won't be the same as 1/200th), but for some reason, I thought it was a lot more complex than that.

To follow on from this, when shooting with wider apertures that require faster shutter speed than 1/200th, and the lights are already low as they can go - are my only options ND filters or similar?

I'm trying to figure out how strobes relate to my settings a little clearer, now I have some monoblocks to play with!

Jon wrote in post #9347524
Unless you've got very high ambient light levels the shutter speed (assuming it's slower than sync speed) is, within reason, irrelevant. If you slow the shutter speed 5-6 stops (in normal conditions), the ambient light may begin to make itself known. The darker the ambient light, the less difference shutter speed makes.

Thanks Jon, that helps me understand things.

Shutter speed controls ambient light

Aperture controls strobe

Think of the flash as instantaneous. The "max sync speed" on your camera is the maximum shutter speed that will expose the whole sensor to that instantaneous flash. So as long as your shutter speed is at or below your max sync speed, the amount of light you get from your flash is constant (assuming constant flash power setting) regardless of how slow of a shutter speed you use. 1/200 lets in the same amount of FLASH light as 20 seconds. That's an important concept to understand.

Again assuming a constant flash power setting, the way you control how much flash light you let in is by changing the aperture setting. A wider aperture will allow more of that instantaneous flash through, while a smaller aperture will allow less of it in.

Now in addition to this instantaneous burst of flash from your flash gun, there's also some level of ambient light. The ambient light is constant and how much ambient light you allow WILL change as you change shutter speeds and aperture - just as it does without a flash involved.

There's lots of playing you can do on combining flash and ambient.