Jumping portraits. blur

stokes

stokes

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Tom
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Ive started to enjoy portrait photography and have been taking photos at the school i work at before and during our Christmas play.

Last night i decided it would be fun to get some fun shots of the kids jumping, i used the same settings as i had been using all night.

Nikon d90
24mm
1/30th second
f8
using a sb28 on half power through a softbox.

I ended up with blur on the kids hands when they were moving. I have been watching the "one light" dvds and the guy on there mentioned that shutter speed didn't really effect portrait stuff..

Didn't really notice the blur on camera, only when i got home so didnt have a chance to change the settings...

Do i simply need to speed the shutter up? Go upto the d90's max of 200th of a second whilst using flash?
 
1/125th should be ok, in 'normal' portrait stuff 1/30th wouldnt usually present too much of a problem, but jumping ain't normal!
 
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when you work with flash based lighting you get 2 simultaneous exposures, flash and ambient, the flash is basically instantaneous and the ambient here is a 1/30th in most circumstances that would register maybe underexposed maybe a stop or two but enough to show the blur
 
Blasteh said:
pics

and what's the ambient exposure?
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Cant put pics up, i only have permission for using the photos for school purposes. Sounds silly i know, but my jobs important. Not that i dont trust anyone here :)

Will try and shoot at as fast a speed as i can without getting the shutter curtain. if i still get blur, i will recreate a shot and post it.

Adeyb said:
1/125th should be ok, in 'normal' portrait stuff 1/30th wouldnt usually present too much of a problem, but jumping ain't normal!
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Lol. Thanks, ive seen loads of those sorts of portraits... will try 1/125th

david1701 said:
when you work with flash based lighting you get 2 simultaneous exposures, flash and ambient, the flash is basically instantaneous and the ambient here is a 1/30th in most circumstances that would register maybe underexposed maybe a stop or two but enough to show the blur
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Thanks for the info. will bump up the shutter speed :) thankyou.
 
kokakaste2 said:
Speedlites have their shortest (fastest) flash duration at lower power, full power blast is slow. Somewhat good explanation. Try again with 1/16 or so power :) and make sure ambient is few stops below flash exposure. :)
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Unlikely problem, unless you are shooting an object moving seriously fast.

Quick google finds:
SB28 1/1100 sec. @ 1/2 output

That's fast enough.
 
Blasteh said:
Unlikely problem, unless you are shooting an object moving seriously fast.

Quick google finds:
SB28 1/1100 sec. @ 1/2 output

That's fast enough.
Click to expand...

True, 1/1100 (guess thats t.5) is fast :) but you never know how fast they jump. :p

In other words, you just can't take it out of the equation, it might be that it was not fast enough.
 
Sometimes a little blur in a portrait can be good - here's one of a kid clapping - note the blur . . .

1AW_1175.jpg


You just have to use a shutter speed to control the blur the way you want it.
 
It isn't about actual movement speed, it's about relative speed and direction of movement, i.e. it's about how far the subject moves across the sensor during the flash exposure.

A F1 car a long way away and heading directly towards the lens at 200 MPH can be moving much slower in relative terms than an ant at extreme closeup walking across the frame. It's my guess that jumping kids will be moving their hands pretty quickly, so you'll need the shortest flash duration you can possibly get if you want to freeze the movement.

But sometimes a bit of movement blur looks better, it makes the shot look real.
 
awp said:
Sometimes a little blur in a portrait can be good - here's one of a kid clapping - note the blur . . .


You just have to use a shutter speed to control the blur the way you want it.
Click to expand...

Beat me to it:)
 
stokes said:
I have been watching the "one light" dvds and the guy on there mentioned that shutter speed didn't really effect portrait stuff..
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He's wrong.

Or rather that's an incomplete statement of the truth ;) Once your shutter gets to 4 - 5 stops faster than an ambient exposure the shutter speed has almost no effect on the image. But slower than that you'll get a mixed exposure. And for moving subject mixed can = blurred.
 
JonathanRyan said:
He's wrong.

Or rather that's an incomplete statement of the truth ;) Once your shutter gets to 4 - 5 stops faster than an ambient exposure the shutter speed has almost no effect on the image. But slower than that you'll get a mixed exposure. And for moving subject mixed can = blurred.
Click to expand...

Nope, you're wrong.

Shutter is unable to control flash exposure as the pop of the flash is generally 1/600th or above, when sync speed is up to 1/250th at max.

Only the aperture can control the amount of flash power hitting the sensor, and the use of aperture also controls the ambient.

The way shutter speed effects flash power is ambient light. You need to make sure the subject is not exposed at ambient level, this is where blur occurs. To use flash at speeds of 1/30th etc then you need to make sure the subject is under exposed (usually by one stop or more) rather than exposed correctly at ambient (control exposure via shutter if poss or if not aperture and iso) and a flash used to expose the shot. If using a flash that auto exposes make sure you set it +1 on the exposure to get the result.

kokakaste2 said:
True, 1/1100 (guess thats t.5) is fast :) but you never know how fast they jump. :p

In other words, you just can't take it out of the equation, it might be that it was not fast enough.
Click to expand...

Most flashguns easily have flash durations of 1/1100 or more T1 times at half and below.
 
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Um, apart from you saying that the subject should be "underexposed" by 1 stop and me saying that to be absolutely sure you need to be 4 - 5 stops away.......how is that different from what I was saying?
 
JonathanRyan said:
Um, apart from you saying that the subject should be "underexposed" by 1 stop and me saying that to be absolutely sure you need to be 4 - 5 stops away.......how is that different from what I was saying?
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I think its more a misunderstanding of how flash works / what ZA said than anything else its 'shutter does not affect flash exposure' which is true but I'm pretty sure he explains that the camera registers ambient too (or that might have just been David Hobby
 
Nope. You've lost me.

I think we're all pretty clear that if you take a shot at (say) f/5.6 / 1/30s and it's blurry that using flash without changing anything else wouldn't magically remove the blur.
 
I misread Tom's quote. Basically Zack Arias states that shutter speed does not effect flash exposure, which is correct. That is the point about the T1 times (T5 should be halved to give an accurate ish flash duration which is what freezes the action.

In the DVD he states that aperture controls flash exposure and shutter is for controlling ambient, which although a little simplified is the best way to think about things when you are learning manual flash techniques.
 
To the OP, I suspect that in your pictures you have both a blurred ambient light exposure (that's the 1/30sec part) overlaid with a sharp flash image - something like awp's pic above. If the sharp flash image is faint, then the flash is under exposed - quite common if you're shooting at any distance.

If you don't want the blur, raise the shutter speed up to the x-sync max (1/200sec) and that will leave just the sharp flash image. The background will go darker though.

Personally, I prefer a bit of blur within reason. Hands and feet etc are fine, so long as the faces are sharp.
 
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thanks for all the help and suggestions. planning on getting the wife to do some poses for me tomorrow, so will play around with the settings a bit more.

Thanks Richard, i think you have hit the nail on the head :) Ive just reviewed some of the shots in question and i do have a blurred bit and then a sharp image underneath.
 
stokes said:
Ive started to enjoy portrait photography and have been taking photos at the school i work at before and during our Christmas play.

Last night i decided it would be fun to get some fun shots of the kids jumping, i used the same settings as i had been using all night.

Nikon d90
24mm
1/30th second
f8
using a sb28 on half power through a softbox.

I ended up with blur on the kids hands when they were moving. I have been watching the "one light" dvds and the guy on there mentioned that shutter speed didn't really effect portrait stuff..

Didn't really notice the blur on camera, only when i got home so didnt have a chance to change the settings...

Do i simply need to speed the shutter up? Go upto the d90's max of 200th of a second whilst using flash?
Click to expand...

http://www.youtube.com/watch?v=rl9yRJZtMA8&feature=more_related
 
Actually kids move pretty fast even when they don't need to, excitement induced movement (just made that up) taking shot of my 5 year old inside a well lite room at 1/30 would be all blurry, flash on half power through a soft box might not be strong enough for that speed.

poss a ring light may have worked :shrug:

Aslo check your iso and WB as well

Merc
 
Thats an I'll informed blind guess.
 
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