Need to stop action with which flash? Canon or Alien Bee?

At 20,000th or 30,000th, the flash will definitely stop motion. Take a picture of a faucet on max and everything should be frozen. Same thing with a fan.

The ab is the one we're not sure about.

Going Baroque wrote in post #11780346
It's actually the same, as per Galileo. .

well..yeah...that what I meant they'll both end up falling at the same speed due to gravity...9.8 m/s^2.

suecassidy wrote in post #11779438
I got nuthin', but am interested in hearing from those who know about such things. I would THINK that the more light you have, the faster shutter speed you can use, which would be crucial in stopping the action. If that notion is correct, I would think that your Alien Bee would do a better job of that than your 430 EX would? I'm just blowing hot air because I have zero experience with shooting super fast action like that, I'm just thinking out loud. I'm sure somebody here knows and will set us both straight.

The brightness of the flash or strobe has nothing to do with the fastest shutter speed you can use. For digital SLR cameras, the fastest shutter speed is determined by the max sync speed of the camera which is usually 1/200 or 1/250. In the absence of ambient light, it's the flash duration which determines whether action can be frozen or not.

Attached are images shot with the AB400 and the 580EX II at different power levels. Since the AB400 has the shortest flash duration at full power, I only shot one image using the AB400 and that was at full power. As you can see, the flash duration was not fast enough to freeze the blades of an electric fan running at medium speed.

At full power, the 580EX II actually did worse than the AB400 since the blades of the fan are blurrier. However, at 1/4 power, the blur is very slight and can barely be seen. And at 1/8 power, the blade is essentially frozen.

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Yeah... what he said ^^ ;P

MOST EXCELLENT! That answers my questions. Thanks to all for the input!

PacAce wrote in post #11780469
The brightness of the flash or strobe has nothing to do with the fastest shutter speed you can use. For digital SLR cameras, the fastest shutter speed is determined by the max sync speed of the camera which is usually 1/200 or 1/250. In the absence of ambient light, it's the flash duration which determines whether action can be frozen or not.

Attached are images shot with the AB400 and the 580EX II at different power levels. Since the AB400 has the shortest flash duration at full power, I only shot one image using the AB400 and that was at full power. As you can see, the flash duration was not fast enough to freeze the blades of an electric fan running at medium speed.

At full power, the 580EX II actually did worse than the AB400 since the blades of the fan are blurrier. However, at 1/4 power, the blur is very slight and can barely be seen. And at 1/8 power, the blade is essentially frozen.

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forum: Flash and Studio Lighting

What this little exercise shows is that the hotshoe flashes at lower power is better at freezing action or motion than most strobe are. There are exceptions, of course. For example, the AB Einsteins which work essential the same was as hotshoe flashes.

However, to answer the original question, if we're talking about freezing a dropping ball which isn't moving very fast, then either the hotshoe flash or the AB400 should do the trick. For anything really moving fast, though, the hotshoe flash would be the better choice.

When you shoot flash, shutter speed is irrelevant for freezing motion. Your shutter speed is limited by your max x sync (around 1/125 s to 1/250 s depending on your camera). Your shutter speed is mainly chosen to correctly expose your ambient light. HSS is another story.

What will freeze the motion is the flash duration (t.1 and t.5)

The AB800 is an older generation studio strobe.
The speedlight is giving you a far better t1.

for instance here's an average of flash duration for a speedlight 580EX
1/1 power = 1/1000 second
1/2 power = 1/2000
1/4 power = 1/4000
1/8 power = 1/9000
1/16 power = 1/15000
1/32 power = 1/21000
1/64 power = 1/30000
1/128 power = 1/35000


The AB 800 will be for t.1
Full Power: 1/1100 sec.
1/32 Power: 1/550 sec.


If you need more power than a speedlight for your setup, then try to go with new generation IGBT studio strobes like the Einstein (in action mode t.1 from 1/568 s at full power to 1/13500 s at -8f).


But for a ball drop, speedlight is more than enough light.

FWIW, the reason I suggested 430EXII on lowest power in my original response is that it is already the IGBT technology, all of the speedlights are. These "cut off" the energy being dumped to the strobe to limit output, resultng in much shorter duration flash at low power than your 400 AB. The fan example above is a good illustration of this. Also, this speed you will find to be critical in your setup, as it is not the ball droping that is the challenge to freeze, but the splashing drops. In shooting similar splashing drops with my AB's and Speedlights I found the speedlights much better for it, never getting anything acceptable with the AB's

@ PaceAce, nice study..

i was going to say your best bet is speed lights is your best option being you can go into HSS and with alien bees, your limited to 250 SS..

but i think everybody already has stated that speedlights is best for this situation

phamster wrote in post #11781546
@ PaceAce, nice study..

i was going to say your best bet is speed lights is your best option being you can go into HSS and with alien bees, your limited to 250 SS..

but i think everybody already has stated that speedlights is best for this situation

I dont think the shutter is stopping the action I think its the flash duration. HSS is going to be slower.

sigma pi wrote in post #11782701
I dont think the shutter is stopping the action I think its the flash duration. HSS is going to be slower.

That is correct. However, if ambient light is contributing significantly to the exposure, HSS and the faster shutter speed would be the way to freeze relatively slower motion (that is, relative to a 100 mph fast-pitched baseball or a flying bullet ).

PacAce wrote in post #11782732
That is correct. However, if ambient light is contributing significantly to the exposure, HSS and the faster shutter speed would be the way to freeze relatively slower motion (that is, relative to a 100 mph fast-pitched baseball or a flying bullet ).

OH for sure. Agreed 100% ghosting ect ect. I just would assume the OP would turn the lights off or really low since its a studio.

Outside in the sun. Yeah HSS

Hi, I know this thread is 3 years old but Im in a similar predicament and have some relating questions.

Like the OP I only have 1- B400 and a few speed lights (Yongnuo 580's)

Does one have to get a specific trigger to get over the camera sync speed ?
Does my T2i's 1/4000 shutter speed max limit me from producing these type of "liquid splash" shots?

kymira wrote in post #16958279
Hi, I know this thread is 3 years old but Im in a similar predicament and have some relating questions.

Like the OP I only have 1- B400 and a few speed lights (Yongnuo 580's)

Does one have to get a specific trigger to get over the camera sync speed ?
Does my T2i's 1/4000 shutter speed max limit me from producing these type of "liquid splash" shots?

I think you're missing the point of the posts in this thread. Shutter speed is irrelevant when trying to freeze something with flash. What you're actually trying to do is use the flash duration itself to freeze the subject. Use a camera setting that won't allow any ambient light influence (these kind of shots are normally done in a dark room) and use the flash itself to stop the action. That's why flash duration has been the talking point, not shutter speed. Granted you can do it in a dark room with constant light and a fast shutter speed (about 1/1000 should do), but it's easier to just use flash.

Scatterbrained wrote in post #16958466
I think you're missing the point of the posts in this thread. Shutter speed is irrelevant when trying to freeze something with flash. What you're actually trying to do is use the flash duration itself to freeze the subject. Use a camera setting that won't allow any ambient light influence (these kind of shots are normally done in a dark room) and use the flash itself to stop the action. That's why flash duration has been the talking point, not shutter speed. Granted you can do it in a dark room with constant light and a fast shutter speed (about 1/1000 should do), but it's easier to just use flash.

thanks clearing that up

So let me get this right the B400 has a faster duration the higher the power, And is the opposite for speed lights?

How do I counter overexposure at higher power on the B400?

kymira wrote in post #16958486
How do I counter overexposure at higher power on the B400?

combination of these: narrow aperture, low ISO, distance or direction of light and or nd filters (on lens or light).