AF assist and OCF

Hi all,

Wondering if anyone could tell me if it is possible to set up the 7D to use the pop up flash as the AF assist and disable the firing, but at the same time have a 580 exii off camera fire? I can't seem to get this to work unless I hook up another 580 on the hot shoe...

Thanks!
James

I think there is no way to do that. Plus the build in flash is not a very good AF assist. Do you have another flash to put onto the camera? I not you could buy yongnuo 622c, ETTL radio trigger that has a build AF assist.
I have it and to me the af assist works well with the center point. And radio is a lot more reliable than optical slave.

Nope. You need the other 580 on your camera.

Thanks guys!
...I had a feel i would need to buy more stuff.

If you want focus assist, its another reason to consider the YN622c triggers. Its better as a flash controller than the optical canon system and the trigger also has a very nice IR focus assist pattern. I was able to focus with an F4 zoom in a living room lit only by the light of television. Something I could never seem to accomplish with the focus assist on my 580exII.

I bought the Yong Nuo knockoff version of the ST-E2 wireless transmitter, back when I had a t2i that didn't have wireless command. When I upgraded to a 60d, I was at first pissed that I'd spend the money on the wireless transmitter until I discovered that it was really good for the AF - maybe better than the flash itself. So although I can use the dreaded pop-up to fire my 430ex when it's off camera, 8/10, I stick the Yong Nuo transmitter on top and use it. It only costs about $120. Might be worth your while, especially in dark situations.

digitalretouch wrote in post #16021621
I bought the Yong Nuo knockoff version of the ST-E2 wireless transmitter, back when I had a t2i that didn't have wireless command. When I upgraded to a 60d, I was at first pissed that I'd spend the money on the wireless transmitter until I discovered that it was really good for the AF - maybe better than the flash itself. So although I can use the dreaded pop-up to fire my 430ex when it's off camera, 8/10, I stick the Yong Nuo transmitter on top and use it. It only costs about $120. Might be worth your while, especially in dark situations.

Now that you can buy a pair of the radio triggers for the same price, the YN ST-E2 would be a waste of money. A pair of those give you radio flash control and the built in focus assist beam for roughly the same price. They outmoded their own product.

gonzogolf wrote in post #16021634
Now that you can buy a pair of the radio triggers for the same price, the YN ST-E2 would be a waste of money. A pair of those give you radio flash control and the built in focus assist beam for roughly the same price. They outmoded their own product.

See the YN-622C thread for rather a lot more information on this. Two posts pertinent to your particular situation and the post above are https://photography-on-the.net …p=15996350&post​count=2457 and https://photography-on-the.net …p=15997884&post​count=2464

It does work with my 7D and 580EX II.

Wow. Can't thank everyone enough for contributing. I'll have to read into everything a little more but it sounds like a few options exist.
Thanks again!!!

jameswillett wrote in post #16025613
Wow. Can't thank everyone enough for contributing. I'll have to read into everything a little more but it sounds like a few options exist.
Thanks again!!!

I agree, you should be able to do this as oldvultureface described. Make sure your focus mode is AI Focus or One-Shot. Servo focus disables AF Assist, because you could conceivably press the shutter while it was AF assisting, and capture the assist light.

I set the popup of my 7d to wireless function only (the little logo that looks like a firing speedlite on its own, with no popup logo), had a 580ex II on my desk in slave mode, and the popup AF assist fired, and then the 580 was the only contributor to the exposure (all the room lights were off so this was pretty apparent...)