Flash - TTL & E-TTL

I'm looking for a secondary, small, cheap flash for when the 10D built in is too weak and my 420EX is overkill.
Question - what's the difference between TTL and E-TTL?
I've looked at several 3rd party flashed that are Canon EOS dedicated, but most are TTL. Specifically, will the flash exposure compensation on the 10D work with these units.

Shane, you have to watch out for tricky wording. Lots of manufacturers will claim that their flash will work with Canon EOS cameras, and that much may be true. However, Canon EOS film cameras tend to use TTL flash mode, and Canon EOS digital cameras tend to use E-TTL flash mode. Many flash units do not support E-TTL.

In the film days, TTL mode worked by capturing a bit of light intensity bouncing off the film surface and onto some small sensors in front of the film. That could tell the camera's automatic system what to do to the shutter or aperture to cut off excess light, and so the exposure would be correct.

Well, in a digital camera, there is no film! The surface of the main image sensor does not reflect light the same way, so they really could not use TTL mode. Instead, with E-TTL, there is a pre-flash of limited intensity. Some small sensors will read that intensity and then make adjustments quickly in the camera so that the main flash (a tiny fraction of a second later) will result in a proper exposure.

So, if you end up with a TTL-only flash unit, you will have to resort to shooting flash manually. That is not impossible, but it is a skill that the film oldtimers learned. One of the reasons that you purchased a new camera was to get the newer automatic features, such as E-TTL.

---Bob Gross---

Thanks Bob. I'm amazed that Canon doesn't make a mid powered type flash (Guide 80 ft or so). I seriously doubt I'm the only one that dreads adding another couple pounds to the already massive 10D when I just need a bit more power.

There's the 220EX.

Massive? That's not massive.

When I go out for wildlife photography, I have my D60 camera, my 550EX flash, my 420EX flash, my ST-E2 transmitter, one to three tripods, and my Sigma 170-500mm zoom lens. Normally, I can find trees to hang the flash units on, but sometimes I have to use tripods for them.

The trailer for the lens is in the shop now, so I have to lug all of this into the woods.

---Bob Gross---

Try a Nikon F3 with a motor and the 10D will be a lightweight. I got the BG-ED3 vertical grip to ADD WEIGHT since I think that the camera is too light otherwise.

As for flashes I routinely carry a 550EX and two 420EX's in my camera bag. I like to use the wireless TTL function that Canon offers and I never know when I'll need 'em, so they're with me all of the time. The weight penalty is minimal with these three flashes - they weigh less than my Metz 45-CL4 and a Quantum 2 battery - and the results are worth a little pain anyway. What makes my camera bag truly heavy are the L series lenses!

If you don't think the 10D + Speedlite is massive, pick up that film SLR that's been condemned to the closet ever since you got the 10D and see what you think.

Seriously though, I shoot mostly event stuff for radio stations and trying to manuver through a club filled with 1,000 people with this hanging on my neck really sucks. I'm not complaining, and I'm really happy with the 10D, I'm just trying to make my life a bit easier. I shall now investigate the 220EX.

Everything you want to know about flash with the Canon EOS system: http://photonotes.org/​articles/eos-flash/

Beware that the 220EX does not have a tiltable head, so bounce flash is not possible.