Beginner question about toning down TTL flash

[lerabu]

Hello

I am quite new to photography and am still learning all the techniques (even though that it seems never ends ) and I have finally learned how to tone down flash! My amazement was beyond measure when I finally was able to take pictures in darker settings and getting shots of people using the flash and not having them overblown by it in the shot and the rest of the photograph underexposed. A fantastic personal victory and source of inner glee! I actually grinned like a g33k when I made the discovery!

So I am using the following equipment: Nikon D80, Kit-lens 18-105mm 1:3.5-5.6G VR ED. This weekend my in-laws are organising a St. Martin's celebration (wine maturation day - big day here in Croatia). It will be in their tavern and the lighting will be quite poor so I am sure I will to resort to the TTL flash.

Do you have any recommendations as to what setting to use on the TTL flash. Should I put it on REAR when making portraits so that people don't move after the flash has fired?

I reckon I will use ISO 200 or 400 just to get a faster shutter speed upwards of 1/100 sec as there will be children running around too

Thank you for the time you have taken to reply!

[scootermcq]

If the room is dark enough, the flash will freeze your image anyway, so shutter speed is not really an issue. In dark receptions, I will quite often shoot around 1/45-1/60th with people dancing and the images will not blur. You can simply set your shutter to whatever you want (within reason) to allow the amount of ambient light in to the image. Set your aperture for the DOF you want from the shot and leave the flash on TTL and allow it to control the exposure. I usually use rear curtain sync in this situation.

[inkista]

Just personal taste, but if you're going to use slower shutter speeds and shooting people with TTL, I wouldn't be putting the flash on rear-curtain sync, because the time gap between the pre-flash for the TTL and the main flash on rear-curtain might be large enough to register with people and make them blink/move, thinking that the picture has already been taken.

Depends on the shutter speed, though.

[lerabu]

Thank you both for the answers. I will try to capture more spontaneous situations so I hope I will be able to avoid the problem of people moving too early. There is bound to be a few tipsy portraits though, it's a win celebration after all

However I thank you for the suggestion inkista, you speak the truth

Scott, what do you mean by this?

Originally Posted by scootermcq

Set your aperture for the DOF you want from the shot and leave the flash on TTL and allow it to control the exposure

Does the flash automatically control exposure or do you have to set it?

Thanks! And sorry for beginnerisms...

[scootermcq]

If your flash is on manual, then aperture will control the amount of light allowed in to the image, that is why you will hear aperture controls flash. If you are on TTL (talk through lens) then there is a preflash which the camera measures the exposure and adjusts flash power as necissary to properly expose the image.

[inkista]

Slight corrections. TTL is "though-the-lens".

With TTL, what's happening is that your camera tells your flash to send out a "preflash" burst of light of a known brightness. This preflash is then metered by the camera, and the flash power is adjusted to bring that that up to the "proper" flash level. Like all metering-based auto functions in the camera, this is likely to be in the ballpark, but may not be perfect, and is unlikely to be consistent shot to shot, because metering typically changes as the scene in the frame changes.

When you take a flash photo, exposure is not as simple as it is without flash.

Without flash, your exposure is determined by three things: ISO, aperture, and shutter speed. The higher the iso, the wider the aperture, and the slower the shutter speed, the more light you get. If you do not know this, if you are not comfortable shooting with the camera in full Manual and swapping stops among these three settings for ambient exposure, I highly suggest you work on that first, before you add flash into it.

When you add a flash, everything the flash lights is like a second overlaid exposure you're adding to the ambient one. And the flash-only exposure is controlled slightly differently than the ambient exposure. It's controlled by iso, aperture, flash power output, and flash-to-subject distance. (Note how shutter speed isn't in that list. The flash burst is going to be a lot faster than your top shutter speed, so increasing your shutter speed will only increase your ambient exposure, NOT your flash exposure.)

When you shoot a flash picture, what you're going to be worried about is the balance between your ambient and your flash, because how much of each you allow into your photo is going to change the look. You can actually have a huge range of "good" exposure settings with vastly different balances--it's up to you what look you're going for.

The P&S flash "look", that of a brightly illuminated subject, but a completely black background is typical of an ambient/flash balance that's mostly all flash. Your flash is small, it's AA-battery powered. It can only light up a relatively small area of a room--its range is limited. This is typically done by using settings in the camera that don't allow in much ambient light (low iso, fast shutter speed, small aperture), and then blasting the flash power up a lot.

"Fill flash" is the opposite end of the spectrum. The photo will pretty much look as if you hadn't used much flash at all--only flicking a little light in to lift up the shadows, increase contrast, and/or pull in the dynamic range. Using flash to light up the face of someone who was in silhouette is another example of fill flash. This is typically done by letting in a lot of ambient light, and lowering the power on the flash.

And you can choose the balance to be anything in between all-flash and all-ambient. You generally do this by putting the camera into M mode, and setting your ambient exposure settings (iso, aperture, shutter speed) to get what you want out of the ambient, and then adjusting the flash power (either through manual power levels or eTTL and FEC) to get what you want out of the flash (realizing that the flash will mix with the ambient lighting).

See why I said you want to be good with M mode and the iso/aperture/shutter speed exposure triangle before hitting flash?

The website that I'd really recommend going to to learn the basics of on-camera flash photography is Neil van Niekerk's. He's a wedding photographer, and his site and blog are chock full of information on camera flash techniques, and how to think your way through the flash. There's no simple works-every-time single set of settings. You have to know what you're doing.

Once you get all that down, though, then you can swallow the red pill and hit the Strobist and start looking at off-camera flash.

[inkista]

Originally Posted by lerabu

I reckon I will use ISO 200 or 400 just to get a faster shutter speed upwards of 1/100 sec as there will be children running around too

Tiny tiny note. If you want to be kind to your flash and its batteries, don't use a shutter speed faster than 1/200s. That's your max. synch speed.

Details on why here.

And if you want to soften the light from the flash, and your ceilings are low enough and neutral enough in color, I'd suggest practicing bouncing.

[lerabu]

Thank you for the extensive reply!

I have read the articles you recommended and have a better grasp of flash use.

I am using the exposure triangle regularly and am experimenting with manual mode, though when things get hot I still revert back to aperture or shutter priority because I can't get it right in the time needed :P

I will practice with manual and I now see how useful flash really is!

I just need to save up for one of those independent, nonincorporated flashes!