"Dragging The Shutter" question

[pyanista18]

Hey gang,

I feel like I'm doing something wrong here. I'm trying this "Dragging The Shutter" technique and it's not showing me consistent results.

I have my flash and camera in manual mode. I'd set my ISO to 200, shutter speed to the flash sync speed and the correct aperture my light meter recommends. With my flash mounted on a stand, I'd take a shot and see my subject correctly exposed. Now, I want to get the background brighter so I'd slow the shutter speed down.

I thought that this technique is going to brighten (or darken) backgrounds while keeping the subject properly exposed but whenever I'd slow my shutter speed down, even the subject gets brighter.

Did I miss something?

[ttosifa]

In every shot, you have ambient light and strobe light. Ambient light is controlled by both shutter speed and aperture, while strobe light is generally controlled by aperture.

So, in your example, if the subject is lit both by ambient light and strobe light, then slowing the shutter speed will allow more ambient exposure, making your subject brighter. It is only when your subject is entirely lit by flash that changing the shutter speed won't change the subject exposure.

[jdepould]

Try using a higher ISO, that might give you more wiggle room with the shutter speed/background stuff. You may also need to play with aperture and flash power.

[sk66]

You also need to reduce the flash output in order to keep the same total exposure. By increasing the exposure time you are adding more ambient light to the exposure. If you do not cut back the amount of light added by the flash then the total exposure is greater.

[kencaleno]

......If you shoot at a party or wedding reception, indoors at night using the auto or programme flash setting, which is usually either 1/250 or 1/500 second, you will end up with ultra black backgrounds, and not the scene you saw. That is because the flash fired too fast to record background detail. Solution: set camera to shutter priority or manual mode, and adjust speed to between 1/30 and 1/8 second-these are normal settings for fairly dark conditions, because of the actual flash speed,. blur won’t be a problem. This is Known as “Dragging the shutter”.
When using Dragging method keep flash set to auto or ttl, as, unless you are comfortable with doing this , you could complicate matters. If you only have a point and shoot camera, use the night setting-the camera will automatically set shutter speed to allow background detail to be captured, BUT, you will need a tripod/monopod etc, as for night mode shutter speeds are likely to be a lot slower than 1/8second.

© Kenneth William Caleno (Dip Phot) 2010

[OsmosisStudios]

Originally Posted by kencaleno

......If you shoot at a party or wedding reception, indoors at night using the auto or programme flash setting, which is usually either 1/250 or 1/500 second,

Dont know which camera program youre using, but every SLR ive tried in Auto or P shoot at 1/60s

[kencaleno]

Originally Posted by OsmosisStudios

Dont know which camera program youre using, but every SLR ive tried in Auto or P shoot at 1/60s

Don't know what camera you're using, but my D50 maxes at 1/500th sec flash sync, My G1 Lumix maxes at 1/160th sec, and even my old Nikon FE slr(who mentioned SLR anyway?) maxes at 1/90th sec. what planet are you on today? Also my D50 syncs at up to 1/4000th sec with off-camera flash-due to the electro-mechanical shutter (The d70;d70s and the D40 can all sync off-camera at max shutter speed) I don't believe any other cameras are capable of this. Ken

[sk66]

Originally Posted by OsmosisStudios

Dont know which camera program youre using, but every SLR ive tried in Auto or P shoot at 1/60s

He didn't say "Auto or P", he said "Auto or TTL" for flash setting (which I believe are "the same thing" for different brands). And he is correct in that will eliminate the flash issue being discussed. However, it requires on body flash or a TTL cord.

1/60 and 1/200 (1/250 on my D3) are flash sync speeds. Flash shutter speed can be set much lower (even for "auto", up to 30s on my D3) and I think that is probably what was meant. The flash doesn't have to sync with longer exposures because the shutter is open much longer than the flash durration. But the flash output will need reduced (manual or TTL).

To go above the default sync speeds you have to go to FP (which shows as 1/250s in the viewfinder on my D3).

[Alefeb07]

If i were you i would try and fool with the metering modes. It may be metering from just the subject or it may be metering the whole frame. Try and play around with his function and see if it makes any difference.