AF-Assist Only On 1D Mk II Possible?

Just got a 430EX II and am loving it. Was wondering if it's possible to use the AF-assist beam only without the main flash firing. I haven't been able to find a way to do it with the 1D Mk II (which is the body I'm using it on) and thought I'd ask the POTN community.

Thanks in advanced.

As far as I have been able to determine, no. You could always block the output of the flash with a black sock or something similar on the flash head.
Oddly, my lowly old 20D could be set to exactly what you want to do, yet the hot-shot pro body cannot. Go figure.

Lower the flash output or point the flash head up or backwards.

I thought if flash had the feature to let you turn off the flash and keep AF assist (like 580 does) that it doesn't depend on the camera. I only have 550ex on my 1dmk2 which doesn't have that custom function.

Bobby,
I have the 430EX, so I can only speak to that model, but on it, your only option in the CFn menu is to either enable or disable the assist beam.
It's too bad the 1D2 is not set up the same way as the 20D was. But like I said, a black sock over it should do the trick. The only problem with spinning it around backwards is that obviously, he may get some light bounced from a nearby wall.

bobbyz wrote in post #9263041
Lower the flash output or point the flash head up or backwards.

I thought if flash had the feature to let you turn off the flash and keep AF assist (like 580 does) that it doesn't depend on the camera. I only have 550ex on my 1dmk2 which doesn't have that custom function.

Like the 550EX, the 580EX and the 580EX II do not have a custom function that allows you to turn off the flash so that it can be used just for AF assist.

All the 1D models prior to the 1D Mark III had no way to turn off the flash so that it could be used just for AF assist. I guess Canon figured that if you wanted AF assist with one of its pro bodies, you'd get the ST-E2.

At least they eventually wised up with the 1D MK III and put in a custom function to turn off the flash.

Ugh, that's disappointing .

I was trying AF-Assist out and love it. I was able to AF in absolute darkness accurately with the Canon 50mm 1.8 . Granted in that kind of a situation I would want the flash to fire.

Thanks Leo and George.

But one can still put the flash in manual mode at 1/128 and use the assist beam, isn't it?

george m w wrote in post #9263089
Bobby,
I have the 430EX, so I can only speak to that model, but on it, your only option in the CFn menu is to either enable or disable the assist beam.
It's too bad the 1D2 is not set up the same way as the 20D was. But like I said, a black sock over it should do the trick. The only problem with spinning it around backwards is that obviously, he may get some light bounced from a nearby wall.

The black sock trick would cause excessive heat buildup, not a good workaround

I've heard that mentioned, but was not sure if there was any truth in it.

For the most part, I can't think of a time when I need the AF assist beam anyway, so it's all kind of a lost point on me. That is interesting to hear about the Mk3 having that feature.

bobbyz wrote in post #9263573
Thanks Leo and George.

But one can still put the flash in manual mode at 1/128 and use the assist beam, isn't it?

I believe the lowest power setting on the 430ex II is 1/64 . Yes, the AF-assist would still fire.

I've heard the same thing about putting anything black over the flash head being a bad idea for heat reasons. There was a video somewhere of a 580ex II burning a hole through a black plastic bag somewhere in a single 1/1 flash.

george m w wrote in post #9263786
I've heard that mentioned, but was not sure if there was any truth in it.

For the most part, I can't think of a time when I need the AF assist beam anyway, so it's all kind of a lost point on me. That is interesting to hear about the Mk3 having that feature.

Yeah, especially if the flash is set to manual and at the lowest power possible. Or, another option is to put an IR filter in front of the flash head. An strip of unexposed but processed slide film works nicely, too (for those who shoot or used to shoot slide film).

Or just take $1 wallmart black foam and make like a honl snoot and put it on flash and point flash up. There are so many ways. Not sure if I would want to use no flash if lighting is so bad that I need AF assist, unless I am shooting with off camera strobes. Even in that case some fill from camera axis can't be bad. And 50mm f1.8 is not a nice low light lens (AF wise).

PacAce wrote in post #9263180
Like the 550EX, the 580EX and the 580EX II do not have a custom function that allows you to turn off the flash so that it can be used just for AF assist.

All the 1D models prior to the 1D Mark III had no way to turn off the flash so that it could be used just for AF assist. I guess Canon figured that if you wanted AF assist with one of its pro bodies, you'd get the ST-E2.

At least they eventually wised up with the 1D MK III and put in a custom function to turn off the flash.

OK, I know I have to be reading this thread incorrectly, sorry if I am missing the point...but...you don't need a custom function...just turn off the flash and use the focus assist (at least on the 580EX II-don't know about the 430).

I was having great difficulty focusing in a very low light location (candle light level). I tried my 580EX II, shut off the flash, and focusing was great (the room had very dark ceiling, walls, etc so using the flash wasn't an option).

ToyTrains wrote in post #9266588
OK, I know I have to be reading this thread incorrectly, sorry if I am missing the point...but...you don't need a custom function...just turn off the flash and use the focus assist (at least on the 580EX II-don't know about the 430).

I was having great difficulty focusing in a very low light location (candle light level). I tried my 580EX II, shut off the flash, and focusing was great (the room had very dark ceiling, walls, etc so using the flash wasn't an option).

If the flash is powered off, how can the AF assist on it work? Are you sure that AF assist with the flash was woking? Did you see the red patterned beam emitted by the flash?

PacAce wrote in post #9266855
If the flash is powered off, how can the AF assist on it work? Are you sure that AF assist with the flash was woking? Did you see the red patterned beam emitted by the flash?

OK I lied. I didn't turn the flash off on the flash, I used the camera to do it
(which is maybe what everyone was saying). I tried now and couldn't figure out how to do it on the flash itself.

I now always use the camera menu (5dii) to control the flash and don't do any of the settings on the flash itself (except to put the off camera units into slave mode). No more having to remember what custom setting does what.

The menu is great. It allows you to turn off the flash but still use the af assist.