What is wireless TTL?

[jrigdon112]

What is wireless TTL on an external flash and should I get a flash with wireless TTL? I'm mostly taking portraits of my one year old and some family shots and then lots of snap shots!

[Doug Sundseth]

TTL = Through the Lens flash power setting. The flash will emit a low-power burst and the camera will decide what power level to set the flash at. Wireless TTL is for when the flash (or multiple flashes) are off camera.

When it works, it's darned near magical. When it doesn't, it's not. (Even Joe McNally, the magical unicorn of off-camera flash photography sometimes has problems with wireless TTL.)

As to whether you need it? It depends. Do you want to do the things that it allows or is full-manual flash the way you want to go? Manual works pretty well for me, and it's quite a lot cheaper than any of the wireless TTL options I've looked at.

[jrigdon112]

Originally Posted by Doug Sundseth

TTL = Through the Lens flash power setting. The flash will emit a low-power burst and the camera will decide what power level to set the flash at. Wireless TTL is for when the flash (or multiple flashes) are off camera.

When it works, it's darned near magical. When it doesn't, it's not. (Even Joe McNally, the magical unicorn of off-camera flash photography sometimes has problems with wireless TTL.)

As to whether you need it? It depends. Do you want to do the things that it allows or is full-manual flash the way you want to go? Manual works pretty well for me, and it's quite a lot cheaper than any of the wireless TTL options I've looked at.

Thanks so much for that explanation!! I think for know wireless TTL won't be as big of a deal, but for a second flash someday, I'll probably want it wireless
Thanks again!

[inkista]

Wireless TTL also lets you take full advantage of flashes that have it. A flash that has Wireless TTL capability, tends to have a bunch of other features that are useful on-camera, and having them off-camera can also be useful, even if you shoot with the lights in manual.

These additional features can include high-speed sync (the ability to use a shutter speed faster than your body's max. sync speed [typically 1/200s or 1/250s]), rear-curtain sync (if you shoot Nikon), and remote commanding, where you can set the remote flash's power from the camera back. If you're using manual flash, you have to walk to the flash and set the power on the flash's back. This may not seem like a big deal with one flash in a studio environment. But if you have three flashes, and one of them has been placed somewhere relatively inaccessible (say, over the basket of a basketball court), this can be a lifesaver.

You also HAVE to have wireless TTL capable gear in order to bridge that signal over radio if you want to use TTL-capable triggers like Radiopoppers or the TTL PocketWizard units.

The main weakness of wireless TTL systems is that they use near-infrared light signalling, like a television remote. Indoors, in smaller spaces, this works relatively well. But outdoors, without surfaces for the light to bounce off, range and line-of-sight requirements become more stringent, and radio becomes more reliable and versatile.

I also know that if you shoot Canon, wireless eTTL gives you an additional advantage in that your power levels can actually be set far below the minimum manual setting (1/128 if you have a 580EX II). This is extraordinarily useful with macro/product setups, where the close distances mean that a regular manual flash may put out too much light. I find it indispensable when shooting fountain pens.

Most people will tell you you don't need wireless TTL, when what they're actually saying is that it's too expensive to be worth it. At least for them. You can get by with all-manual gear, depending on what you're shooting. But for run'n'gun event shooting, if you want high-speed sync wirelessly (shallow DoF in the daytime with flash), and for using radio TTL triggers, it may be worth the extra cash. You have to figure it out yourself, based on what and how you shoot.

[jrigdon112]

This was very helpful! Thanks so much!