What do bullets, apples and wedding photography have in common?

[jmichaelc]

How about crank it up (ISO) and stop it down. Just go nuts.<div></div>

[jmichaelc]

Oooh and Jena...........WOW!! I'm loving it!

[khaisy]

my question here for everyone who drag the shutter, Do you keep photos in your book and show it to your clients or this something that you shoot and include with you final proof or just having fun try to capture cool shoot. Thanks

[fotografz]

Ben, I presume you meant increase the ISO as opposed to "knocking it down", or am I

confused? Whether your client like that shot or not, it's pretty cool. Were you on a

monopod/tripod, because I can't figure out how you did that?

 

Khalil, all of this is strictly a matter of personal opinion and taste. Every single album we've

done has some shots where the shutter was set lower than the focal length being used.

Some lower than others. Usually of the dancing because it is more expressive of the

moment than static shots. It's all very experimental at first (which digital promotes IMO).

 

There are a lot of variables when using flash and dragging the shutter. Whether you are

using a wide lens or a long one and how close you are ... whether you use second shutter

or not ... how fast the subject is moving, and whether you pan with the subject or against

their movement ... how much ambient light there is in the background, and whether you

want a lot of it to show up or less to show up (Increase ISO and stop down, decrease ISO

and open up, etc.) ... and then there is pure luck ; -)

 

Here's 2 very different shots where the shutter was lower than the focal length ...

 

The first one was with a 85/1.2L @ f/1.2 with the shutter @ 1/60th and the ISO @ 320. I

set the ISO so I could get to 1/60th, and at f/1.2 the flash contributed less than it

normally would so the subject would blur some ... but not too much.<div></div>

[fotografz]

Here's the second one which was accomplished in a completely different manner.

 

It was with the 24-105L IS @ 24/4. I set the ISO to 800 and shutter @ 1/15th because the

ambient light was relatively low and the lens @ f/4. 24 mm at f/4 provides more depth of

field for the background subjects and ISO 800 picked up the background light, the difussed

ETTL flash was hand held up above my head to light the subject and spill onto the

background subjects (evident by the slight drop shadow on the main subject's lower dress),

which helped "freeze" them.<div></div>

[ben_rubinstein___mancheste]

I meant instead of stopping down which can give too much DOF, knock the iso down to 100 which will give the same effect but with similar DOF.

I did that shot by mistake, I have a nasty habit of knocking the control wheel on the grip with the heel of my hand when shooting, I use the vertical shutter release but have taped over the wheel to stop this kind of thing happening. It does show your point though, in low light you can handhold a 1/20 easily with flash, the grooms face is 'I can see every pore' pin sharp.

[erik_h]

I gotta ask--and mods, feel free to delete this--Anyone know if you can drag the sutter effectively with the age-old Nikon F3 / SB16 combination? I suspect I can only accomplish it by going full manual on flash and camera, but maybe I"m wrong.

[picturesque]

Erik--automated flash mode, manual camera mode should work fine.

 

Anyone have any useful info about a situation where you are using some powerful monolights, for instance, to bounce off the ceiling, in conjunction with on-camera flash where the flash duration from the monolights is much longer than the flash duration from the on-camera flash--resulting in ghosting, or double image? Some of the flash durations on powerful flashes are about 1/200th or so.

[conraderb]

Nadine - Interesting question. In my reading of this, I seem to remember that even very powerful flashes are still pretty quick - ie. a very very powerful flash might be 1/300th or a second. I'll give it a try at my next wedding, but I think that the real ghosting problem is just from ambient light creeping into a frame, which you can stop by upping hte shutter speed to the max sync. I shoot w/ my 20D at 1/250th with alien bee lights pretty routinely when I want to kill the ambient, and it works well.

[discpad]

Nadine,

 

Actually, powerful studio strobes have quite an "afterburn," sometimes in the 1/10th second range. The reason is that the big capacitors in the power pack take a finite time to discharge through the arc resistance -- In other words, a simple RC circuit.

 

The way a strobe works is that a voltage is put on the (anode & cathode) electrodes, which is (in an arm-waving sense) "backed up" by the capacitor bank for the "punch." Typically this about 330 volts for a strobe powered from 120 VAC wallplug current; but in any case it's below the flashover voltage.

 

If you look at the flash tube closely, you'll also see a very thin wire wrapped around the tube: This is the trigger wire. What happens is that a high voltage but low current is passed through this coil, which barely ionizes the xenon gas inside the tube... Just enough to allow flashover from the main electrodes. At this point, the resistance is now that of the plasma arc itself, and it lights up.

 

The question is now "How long does the arc stay lit?" The answer is when the voltage drops below that needed to maintain the arc that was struck: This is the product of the arc resistance times the size of the capacitor bank, i.e. the larger the capacitors, i.e. the higher the power rating of the strobe power pack, the longer the arc duration.

 

In typical on-camera flashes powered by four AA batteries (such as my SB-28DX or 54MZ-3) the capacitors are relatively small -- On the order of a few dozen watt-seconds, which means an arc duration in the hundreds of microseconds duration... That is, if the TTL circuit doesn't call for the flash to be shut off first!

 

On the other hand, big strobe power packs have stored energy ratings in the thousands of watt-seconds (=joules), needed to overcome stopped-down lenses (like f/32 or even f/45) for razor-sharp images (for, say, product photography onto LF chromes). Because the stored energy in the capacitor bank is two orders of magnitude more than that lowly SB-28, that (essentially) means the arc duration will be two orders of magnitude longer... Into the 1/10th second ballpark.

 

Cheers! Dan

 

PS: I'm an electrical engineer...

[fotografz]

Interesting. But I have to admit to being confused.

 

I cannot find a single mono strobe with a duration longer than 1/600th, and that's for the

inexpensive Calumet 750 w/s unit. Calumet 375 w/s is 1/900th. The Photogenic 1000 w/s

mono is 1/770th, and their 500 w/s unit is 1/1300th.

 

Move into more expensive units like Elinchrom 750 w/s @ 1/2350th & even their older

design 500 w/s at full output is 1/2600th.

[adam_koch]

<p>I know this tread is very dead but I ran across while searching if anyone knew of a manufacturer of flash triggering devices for high speed photography and I felt like clarifying some things, anyway to get to the point... <br /> <br /> Edgerton used a microphone and a home-built device to trigger a strobe (sometimes he used a photoelectric cell and a light beam) based on the report of the weapon, he left the shutter open in a pitch black room. Gun fires, mic picks up the crack of the shot, flash fires room goes back to black. The hardest part is actually positioning the mic since most rounds are super-sonic the bullet hits the target before the actual report makes it to the target, luckily calculating ballistics is easy, well at least nowadays.<br /> <br /> Off-topic but nonetheless interesting.</p>