Freezing a dancer jumping with flash and flash duration advice

[teigas]

I am doing an experiment this Sunday. I am going to try to freeze a dancer when doing a leap or a dance jump (will try to add motion later on). I want to use flash light to achieve this since its indoor and a dark place and i just want to try it out, because its nice to try new things in life. I have read a little at strobist on the dance blog posts from David. I have a few questions regarding flash duration and technique.

This is just a quick test in a gymnastic hall to see if I mangae to freeze her jumping, if it turn out good, i have acces to a movie thether with a stage, but i dont think we are allowed to use the stage lights, so again we will need to use the flashes. I have used the day on google and I think i understand some of it atleast, but i want to double check and make sure that I am correct.

1. To get the dancer sharp it does not matter if the shutter speed in the camera is really fast? Like say a few stops over 1/200? If the rooms is dark or I block out all the ambient light. Or am I wrong her?

2. I think after some Google reading that it is the duration of the flash that freezes the dancer or water drops or what I am going to shoot? So even if I had the camera on high speed sync and have a faster shutter time this would not matter?

3. I have two Nikon S900 speed lights, and two Elinchrome 500brx (500watt) speed lights. I have read in the Nikon User manual that the duration of the flash at 1/1 is 1/880sec and if I go down on the power it becomes even faster/shorter at 1/64 power it has have 1/35700.
I am not sure if this is t1 or t5?
If I check the flash duration on the studio lights the specs says that Flash duration t0.5 at max. power in s.1/1558 .
If I understand this correct the nikon speedlights are better to freeze motion of the dancer because they have a lot shorter flash duration? And the elinchrome will get her blurry? Am i wrong her?

5.If the Nikon Speedlights are the better choice they have a list of power and duration, what is the highest power you recommend if I need to get the dancer complete frozen in the air. I guess I can try it out when I do the test also. Just wanted to hear if you have tried it before and have any recommendations:
1/880 sec. at M1/1 (full) output
1/1100 sec. at M1/2 output
1/2550 sec. at M1/4 output
1/5000 sec. at M1/8 output
1/10,000 sec. at M1/16 output
1/20,000 sec. at M1/32 output
1/35,700 sec. at M1/64 output
1/38,500 sec. at M1/128 output

Also if sombody her has tried shooting dance with only flash or stopped motion, it would be great to see examples and perhaps light setups.. And where you would place the flash to stop motion the best. I have read some examples on strobist.

[Shadowman]

Also, where will you be positioned in reference to the dancer, will the dancer be facing you directly or at 3/4 view? Looks like you want to prevent a ghostly appearance with the flash output suggested.

[teigas]

I want to freeze her/stop motion to make sure that she is not blurry..I guess somthing in the lines of this if we have a wall and she would be sideways.. Will i guess try out different poses and forward and sideways, etc. Just experimenting. Not so much that i exhaust her.

Perhaps somthing like this at least this https://s-media-cache-ak0.pinimg.com...7796833f6a.jpg

And perhaps from the side: http://img08.deviantart.net/8825/i/2...ty-d4oq4s8.jpg

[Shadowman]

I want to freeze her/stop motion to make sure that she is not blurry..I guess somthing in the lines of this if we have a wall and she would be sideways.. Will i guess try out different poses and forward and sideways, etc. Just experimenting. Not so much that i exhaust her.

Perhaps somthing like this at least this https://s-media-cache-ak0.pinimg.com...7796833f6a.jpg

And perhaps from the side: http://img08.deviantart.net/8825/i/2...ty-d4oq4s8.jpg

I'm sure you are aware of specific shutter speeds needed to stop action and it depends on the subject's position to you the shooter. If the subject is moving towards you shutter speeds can be as slow as 1/125sec, about 1/500sec or faster if subject is moving at a diagonal or parallel and this is in good light.

[Rider in the Sky]

Please use our search box. A very detailed discussion about your topic was posted . I'm sure it will help you a lot.

[Manfred M]

The "secret" to getting a frozen shot is to catch the shot at the top of the jump. At that instance the person is essentially motionless. At that point all your questions about flash, shutter speeds, etc. become far less important.

Your flash is going to in the order of 1/1000th sec, so that should be sufficient to freeze any motion, regardless of shutter speed.

[Rider in the Sky]

Teigas 48,

Please refer to this previous 17th August 2015, 07:17 AM thread posted by Teigas 48

Shooting dancer in theater freezing motion with flash

Shooting dancer in theater freezing motion with flash

GrumpyDiver , William and many others gave Teigas 48 detailed advice.

[Manfred M]

Teigas 48,

Please refer to this previous 17th August 2015, 07:17 AM thread posted by Teigas 48


Shooting dancer in theater freezing motion with flash

GrumpyDiver , William and many others gave Teigas 48 detailed advice.

And that was the last time that Teigas 48 visited CiC. The answers are still valid, but this time you showed us images that are essentially stationary jumps, rather than running jumps. These are technically easier to capture.

[Mike Buckley]

The "secret" to getting a frozen shot is to catch the shot at the top of the jump. At that instance the person is essentially motionless.

True. However, the position of the dancer at that point may not be as appealing as at other points when there is a relatively large amount of motion.

[Manfred M]

True. However, the position of the dancer at that point may not be as appealing as at other points when there is a relatively large amount of motion.

If you look at the sample shots, these would be easy to capture this way.

[Mike Buckley]

There are no sample shots displayed in this thread. If they're in the other thread or accessed by a link provided in this thread, I didn't look at them.

[Manfred M]

There are no sample shots displayed in this thread. If they're in the other thread or accessed by a link provided in this thread, I didn't look at them.

Look at Post #3 in this thread.

[teigas]

Thank you for the advices, i got a few tips from strobist facebook group also. I forgot the post i made in august, because i did not think the dancer that never had time would find the time in the future. But when i asked again this week she could give it a test on sunday. The dancer is not a profesional dancer just a girl that is 17 years old and like to dance and takes dance classes in the local area. We live in a small local town in Norway, so its mostly an experiment for me to try to freeze motion when she jumps and perhaps later on try some creative shots with second curtain, so regarding the poses and postions we dont have any thing really planed out we are going to do a test on sunday. Where we test the lights and have a talk and see what she is able to do. I have only seen her dance at a local gathering in hounor of people familyes have lost over the years called heartpeace. This is her in 2012 i was not so good at shooting then, and i see the shutter speed was way to slow, i did not use flash her: This is a another one from the same day:
I have shot some dancer last year that had a show, but that was more conteperary/modern and more a concept than jumps.
Also followed some dancer friends that used to live her that made a dance movie outdoors, but not that much movement and jumps there either and i was not allowed to use flash since it would disturbe the movie and show up in the actuall movie: Her is some pictures from that if intersted in looking: http://www.teigen.be/blogg/?p=8807# the last once are at really high iso. was getting dark.

Her is some i shot at a local cultar festival for practice: http://www.teigen.be/blogg/?p=9243#
I was not allowed to use flash her either, used it on the last two that was just an experiment.

When it comes to this sunday It will be in a (small) gymnastic hall as I said on the first post. And the purpose is just to see if i can get the timing, lightning and the freezing right, and see what she can do. If we got time we might try some second curtain stuff also.

Moving on to the flash stuff, since i hope that she will try one more time if we get it right, we will move on to a movie theather with a stage and black curtains in front of the movie theather. I dont think we will be allowed to use stage lights, so the plan her was also to use the flashes, so thats why i am doing the experiment before borrowing the movie theather.

I asked a little around at strobist facebook group the same questions that i asked her. I think i understand the concept now.
If i am inside and i use a shutter speed of 1/200 on the camera and the ambient lights are shut of or mostly shut off. The only thing that freezes her to get her sharp is the flash duration. The shorter the flash duration is the better it freezes the subject.

So in strobist they said that the elinchrome flashes where to slow, and i should use the speedlights.
Qutes from strobist facebook

"when using any type of flash in studio, shutter speed below the sync speed will not effect the image, provided the is no light such as modelling lights that can add enough light to add to the exposure. The BRX units flash at 1/1558t.5 will create motion blur on faster moves such as jumps, the nikon speedlites will have less power but more action stopping durations.

Also a little insight into what t0.5 means, it means that that is the amount of time for the flash to decay by half, meaning the time that it take the flash power to drop by half after a flash has been fired. when freezing motion you need to know the t0.1 value which is about 3 times longer then this, The t0.1 value is the amount of time it take the flash to reach 1/10 of its original intensity when fired, and therefore has little to no effect on the picture.
The BRX in this case has a t0.1 of 1/520 meaning you will have a huge amount of blur. you need a t0.1 duration of around 1/1500 which is around t0.5 1/4500. you are better sticking with speedlites in the case"

Then I asked: thank you for the good insight.. I am not sure about the t.01 yet, i think i need to read it some times to understand it completly. Do you know what scale nikon sb900 has used in the specs? If you look at the table i attach her, what is the highest power i can use to freeze her..
1/880 sec. at M1/1 (full) output
1/1100 sec. at M1/2 output
1/2550 sec. at M1/4 output
1/5000 sec. at M1/8 output
1/10,000 sec. at M1/16 output
1/20,000 sec. at M1/32 output
1/35,700 sec. at M1/64 output
1/38,500 sec. at M1/128 outpu

He replyed:
anything below 1/16th power for sure, you consul try 1/8th, will depend on the moves she dose, here is some good reading on flash duration it will help you with the t0.1 t0.5 notations, http://www.shootsimaging.co.za/.../flash-duration-t1-vs...

while it think of it due to the way speedlites fire they electronically cut the flash after the desired amount of light output has been reached so you may even be able to shoot wing 1/4 power on the sb900. would love to hear and see how you get on!

Then there where a lady that ment i should use HSS. :Or go out of the box here and use say 1/1000 -1/4000 to freesze moment, use sb800/900/910 in ttl mode either on camera or off camera linked by radio linked ttl transcievers.

No it would just decrease the amount of light output of the flashes, once you go into high speed sync, at 1/1 marked on your speedlite your only really getting 1/16th of the power, in studio you rely solely on the flash duration, on location is a different story

Well go try it, do be arm chair experts. I use that to freeze a 1,2,3 jump shot indoors; no motion blur looked like a levitation shot. The fact that in HSS, your flash goes into a flash strobe shooting mode - pop pop pop - this is much like stop motion flashing combined with the higher shutter speed of the camera, motion is effectively frozen. To use flash to freeze you not surprising need to be shooting at 1/16 power or lower to get the fast flash duration time;you now will have to guess right or exposure's off, hss allows for a little automation on flash exposure which may just make a one shot take. Of course you will need to up the iso to compensate for the lower flash power in both cases - all bets are off if insanity rules and you shoot at iso 100-320; be creative ramp it up. Out doors if your subject is back lit, you will be in a HSS situation which could call for more than what 1 small flash can supply; either gang them up or use some thing that has more power like a AD360 or best a 500w B1 equivalent.


So to sum up, i think i will try the Nikon Sb900 on the power that lets me get the exposure I want and the flash duration i Need. If it gets do dark i can perhaps add one more one the side of the other, or raise the iso.

Hope you people have some pointers , seems you guys also have a lot of insight. I might be totaly wrong

[Manfred M]

I think the best thing for you to do is go out and do exactly what you are planning to do and test. Ideally the tests would occur where you will be doing the shoot, but this does not look like it will be possible for you.

A few things for you to ponder:

1. HSS may give you the ability to shoot at shutter speeds above synch speed, but it comes at a considerable cost. You loose about 2 stops of power, so while you can shoot faster, your flash is running at around 1/4 of the light output. In the shooting situation you are in, that is likely going to hurt more than help.

2. TTL mode is great, but like most automation, it suffers in repeatability. In difficult lighting situations like the one you are looking at, I tend to shoot manual flash. I find this gives you more consistent results. I tend to set up with a flash meter, but trial & error and looking at your histogram will get you there too.

3. You are not going to be able to shoot in total darkness; so there will be some ambient lighting on the set. Too little ambient light would be dangerous for the dancer and difficult for you as the photographer.

I would put some contrast tape (white on a black floor or black on a white floor) to give the dancer a que as to where she needs to be for her shot. I would also do the same for the camera position.

4. You are going to have to pre-focus the shot (manually focus and then turn off the autofocus in the camera) to maximize your chance of success on the shot. You are correctly concerned about motion blur, but I would be just as concerned about nailing focus. Use a relatively forgiving aperture (I'd start at f/8 and see where that takes me).

5. If you can shoot tethered, this is the type of shot where this would be a good technique to use. The small screen on your camera will not show you that you froze the action and got the focus correct. Viewing the shots on a laptop as you are shooting would be a real benefit here.

6. I would probably shoot with a tripod and have the camera on a cable release. That way you can concentrate on the timing of the jump without worrying about the other technical aspects of handling the camera. Just to repeat, I would shoot on manual; exposure, aperture, ISO and flash settings.

7. Don't forget that in flash work; you have to be concerned with three different light sources; the direct flash, the indirect light from the flash and the ambient light. To freeze the dancer, you want to minimize the impact of the ambient light, so take a test shot and set your ISO / aperture setting so that the ambient light does not have any meaningful impact on your exposure. Then add the flash and control the exposure by the amount of flash (i.e. don't touch the shutter speed, aperture or ISO).

8. I find the folks over at the Strobist are a bit too small-flash oriented. While what they say about the advantages of small flash for this type of shooting.

They forget about the downside; small light source = harsh light with relatively low power. The SB900 has a lot of power, but go easy on it as it is prone to overheating. Don't forget that the AD360 has 5 times the power output of the SB900 and the B1 has about 7 times the output of the SB900.

9. Light stands - I would definitely have the main light on a light stand and have it fairly high and shooting down (positions and angles are something you will have to play around with). Positioning should be well away from where the dancer might land or move. Definitely sandbag it, as you don't want it falling over. If you use a secondary light source (also on a weighted stand), make sure it is set to a lower output (say 1-stop) than your main light. Two equal light sources coming from different directions do give you strange looking lighting.

10. If the SB900 works, consider dragging the shutter to get motion blur and then freeze the dancer using flash. Set your camera to 2nd curtain mode to do these shots. They can be extremely interesting. Again if you shoot tethered, you can tweak your shutter speed to give you the amount of motion blur you like.

[dje]

Hi Teigus

I did some measurements on my D610 with an SB500 Speedlight a while ago. I can confirm that flash duration does drop with power level. Also if you have two Auto FP settings (1/200 and 1/250 in my case), you should select the faster of the two (1/250) and set your shutter speed to this speed also. This will help to get the shortest flash duration.

My measurements indicated the following

Full power, Auto FP= 1/250 SS= 1/250 Flash Duration = 0.4 ms (1/2500 sec)
Half Power, Auto FP= 1/250 SS= 1/250 Flash Duration = 0.4 ms (1/2500 sec)
Quarter Power, Auto FP= 1/250 SS= 1/250 Flash Duration = 0.3 ms (1/3300 sec)

These figures are for the SB500 of course and may be different for the SB900. You probably wouldn't want to go below 1/4 power as you want the flash to dominate the lighting and the flash duration should be well and truly fast enough at this setting to freeze motion.

I wouldn't worry about the t0.5 figure. That is not really relevant when the Speedlight is used with a Nikon camera supporting CLS as the flash is cut-off much quicker than the t0.5 time in most cases.

Dave

[Manfred M]

Also if you have two Auto FP settings (1/200 and 1/250 in my case), you should select the faster of the two (1/250) and set your shutter speed to this speed also.

Dave - I'm not 100% sure that this is correct if you are shooting anything other than Speedlights. Studio flash (and I suspect that will include the Godox AD360 and Elinchrom B1 that Teigas is looking at using) take longer to get up to full output (which is where the t0.1 and t0.5 values become interesting) and the shutter curtain can start closing before the flash is producing "meaningful" light output.

When I shoot studio lights, I find I sometimes have to shoot at shutter speeds below synch speed to get a properly exposed image. I find that 1/200th is a better bet than 1/250th on the D800.

[Loose Canon]

I wouldn't worry about the t0.5 figure. That is not really relevant when the Speedlight is used with a Nikon camera supporting CLS as the flash is cut-off much quicker than the t0.5 time in most cases.

I don't use Nikon systems so maybe one of you might help me understand this. If you are shooting with manual flash, how and for what reason does the camera cut off the flash "much quicker"'than the 50% decay point?

[Manfred M]

I don't use Nikon systems so maybe one of you might help me understand this. If you are shooting with manual flash, how and for what reason does the camera cut off the flash "much quicker"'than the 50% decay point?

When Dave mentions Nikon CLS, he is referring to the TTL control mode, so the flash would not be on manual.

[dje]

Dave - I'm not 100% sure that this is correct if you are shooting anything other than Speedlights. Studio flash (and I suspect that will include the Godox AD360 and Elinchrom B1 that Teigas is looking at using) take longer to get up to full output (which is where the t0.1 and t0.5 values become interesting) and the shutter curtain can start closing before the flash is producing "meaningful" light output.

When I shoot studio lights, I find I sometimes have to shoot at shutter speeds below synch speed to get a properly exposed image. I find that 1/200th is a better bet than 1/250th on the D800.

Yes Manfred I was referring to Speedlights only, and in particular the SB500.

In my tests, a SS of 1/250 with Auto FP set to 1/250 gave a flash duration of 0.3 ms whereas a SS of 1/200 with Auto FP set to 1/200 gave a flash duration of 0.6 ms. I believe this is because with Auto FP set to 1/250, the shutter is fully open for a shorter length of time than it is for a SS of 1/200. But the higher sync speed can give some exposure issues.

I don't use Nikon systems so maybe one of you might help me understand this. If you are shooting with manual flash, how and for what reason does the camera cut off the flash "much quicker"'than the 50% decay point?

Terry and Manfred

The SB500 is not a very smart flash compared to the SB900. The flash itself does not have a manual control but can be operated in a sort of manual mode via the camera. So in these circumstances the CLS is working and controls the flash duration when you manually select a power level in the camera. I'm not sure whether you can work in this mode of operation with the SB900 as I don't have one to test.

It controls the flash duration to suit the shutter speed to make sure the flash is only emitting light when the shutter is fully open.

Hope this makes sense.

Dave

[teigas]

I did a test with the nikon speedlights today, and they are able to freeze the motion at least. I did not get to concerned with where i put the flashes today, because the small gymnastic hall was just for the test. I did test the duration at different speeds not very scientific but experimented a little just for fun my friend was wawing fast at1/1 speed wich gives a t1 one vallue at around 1/250 a little above but you get the point. Lets just say the arms where not sharp, wich i would not expect either. Will show some examples tomorrow. This page also shows a little insight: http://www.shootsimaging.co.za/blog/...-t5-whats-what

There it also have some suggested values:
Person walking briskly = 1/500th to 1/800th
Dancer in large jump or movement = 1/1,000 to 1/2,500th
Pouring water = 1/2,000th
Splashing water = 1/6,000th to 1/8,000th