Can Hi-Speed sync flash stop blurred images

[Tudordoc]

I admit it - but having read both the maual to my 350D and my 420EX flash, I do not really understand Hi_Speed sync.

I have been using my EF 35-135 lens to take pictures indoors. Many of the pictures are somewhat soft. I guess that is mostly due to my handholding and getting a bit of camera shake. I have been shooting using program mode with the ISO at 200. If I were to use Hi_speed sync would this help? What is the best way to set this up? When I turn the flash to hi-speed and the camera to Tv, I can increase the shutter speed but the aperture number flashes at all speeds suggesting the exposure is not right.

Thanks

TudorDoc

[René Damkot]

High speed sync works only at shuttertimes above 1/250s. It emits a pulse of high frequency flashes (around 50kHz). It will not freeze motion as normal flash will. See this (http://webs.lanset.com/rcochran/flash/hss.html) and this (http://photography-on-the.net/forum/showthread.php?t=116998&highlight=HSS)
Apart from that: In P mode the camera assumes the flash is main light. If the ambient is very low, the flash will be the only lightsource. Therefore motion blur should not be possible. Maybe a few examples with EXIF might be helpfull.

[peatoire]

You might have an autofocus problem if it's dark. René is right, P mode should freeze the subject, although it sometimes makes a bad shot if it's quite dark as light fall off at quite a rate. Once you have solved you're soft images problem it will be worth playing with Manual mode with a flash with a slightly longer exposure which will let more ambient light in while the flash should fix your subject.

[chemicalbro]

i've succesfully stopped paint drop crowns with high speed flash at 1/1250
i had way more success with high sync than with normal flash at 1/200.. so i dunno how Rene can say high speed sync won't stop motion like normal flash

[chris clements]

I can't see how high-speed flash can be the right solution for freezing liquid splashes. Instead of a single 'normal' flash to stop movement, you're getting a low powered machinegun burst which lasts muuuuuuch longer.

Unless your ambient light is so high that it's actually the shutter dictating exposure time (ie all the flash is really doing is filling-in)??

It would help if more flashgun manuals emphasised that 'high speed' here has nothing at all to do with freezing motion, but everything to do with fill-in in bright (outdoor) conditions.

[René Damkot]

i've succesfully stopped paint drop crowns with high speed flash at 1/1250
i had way more success with high sync than with normal flash at 1/200..
Probabely too much ambient light. To stop motion, flash should be the main (only) lightsource. Flashpower should be as low as possible, for shortest flash duration. Take a look at the first link....

[ssim]

If I was you I would put the camera in manual mode at about 1/125th and f8 or so and let the flash worry about how much light to emit. I shoot just about all of my flash shots in manual on the camera and it works like a charm.

I would certainly test it both ways but this works for me. If you want to shoot something in high speed you can just bump up your shutter speed to where this applies. In P mode you are telling the camera to solve your exposure and even though you may have the flash in high speed mode, it may not put the shutter speed up that high.

[Titus213]

What ssim says.... Manual mode on the camera is easy with flash. Just keep the shutter speed in flash range and make sure you have enough flash power to iluminate your subject. Blur should not be a problem with flash unless the ambient light is quite high and the shutter speed is low.

[F1_Fan]

I've only skimmed the responses but I don't see this... HSS has a significantly shorter effective range than shooting at or below the sync speed.

Watch the distance display on your flash (if it has one). HSS will drop you to 1-2m effective distance sometimes. I'll use it to freeze motion of cyclists (for example) but in that case I'm squatting right at the apex of the corner.

[chris clements]

At the end of the day the simple answer to the OP's question is "no".

The high speed option is primarily there to fill in all those black eye sockets and long nose shadows you get when shooting portraits outdoors in harsh sunlight.
And it more or less only works for portraits, since high speed flash gives a much reduced range.

[DavidEB]

for freezing water drops, put the flash in manual mode. There's a time gap between the pre-flash and the actual exposure which is long enough for the image to change. Use M mode, set the shutter to 1/250 (max sync speed to shut down ambient lighting), set ISO to 400 and use the largest aperature that gives depth-of-field covering the entire frame (with a 50mm lens at 2 feet, I find about f5.6. Higher ISO and larger aperatures lead to reduced flash duration. Use a tripod, and pre-focus. Then your exposure is set by a few trial-and-error shots as you adjust the flash output manually.

[chris clements]

for freezing water drops, put the flash in manual mode ...adjust the flash output manually.
Remember that the gun varies its output by changing the duration of the flash. So for the best freeze (shortest exposure), go for the lowest manual power setting you can get away with.