ETTL and Alien Bees - DPChallenge Forums

11/07/2005 02:33:02 PM · #1

I use Alien Bees in my studio, I use my mountable flash unit (420EX) on camera (turned toward me) as the trigger for the Bees.
The problem I am having seems to do with ETTL flash. The way I understand it, the camera (20D) actually sends out 2 flashes very quickly, one to meter, one during exposure, but my Bees are responding to the first flash leaving me with unlighted shots.

Is there an easy way around this? Will wired slaving save me? Any suggestions?

PS, I'm reluctant to do wired slave because I move around LOTS in the studio and lights move lots too.

Mr_Pants

SiPix Blink

11/07/2005 02:37:40 PM · #2

One simple solution is to use the FEL button on the camera. This causes the flash unit to emit the pre-flash separately from the main flash. This may well trigger the strobes with the pre-flash, as before. Then wait a while for the capacitors in the studio flashes to recharge and take your shot.

Edit: It's not elegant, but functional.

BTW, I stongly advocate using the FEL button when photographing someone who blinks at camera flashes. Using e-TTL normally, I cannot get a picture of my daughter without her eyes closed, as the pre-flash causes her to blink, an action that is then captured during the main flash a split second later. Using the FEL button judiciously, I get some OK shots.

Message edited by author 2005-11-07 14:40:19.

Prof_Fate

11/07/2005 02:46:17 PM · #3

You cannot use TTL with studio strobes. You MUST shoot in manual mode only.

In TTL the camera adjusts teh duration of the flash to control the light. Since there is no way for the camera to control teh studio strobes in this manner, TTL will not work.

Set your camera on 1/125 or 1/160 and use the aperture to adjust the exposure. F9-13 is the 'normal' range for studio work.

Message edited by author 2005-11-07 14:47:30.

Canon EF 24-105mm f/4.0L IS

11/07/2005 02:47:58 PM · #4

Thank you, Alan. Some great advice there.

Chris, I do shoot manual mode on camera, but the 420EX flash does not have a non-Ettl mode so I can't disable it.

mpemberton

11/07/2005 02:48:26 PM · #5

Have you tried second curtain sync?

Here is also an article on Canon EOS flashes.

EOS flash

Prof_Fate

11/07/2005 02:52:21 PM · #6

How about the pop up flash? you can always block it's effect with some creative use of of an index card and tape.

I bought some cheap ($20 plus shippint) wireless trigger on ebay - it works, but does occasionally trip the flashes for no reason.

something like this- i got hte battery powered version with one channel, but there are several models to choose from.

lwkimages

Canon EOS-5D Mark II

11/07/2005 03:00:25 PM · #7

By your description it sounds like you're using the 420EX just to trigger the Bees... Have you tried the Bees alone? You can trigger the main light via the sync chord that comes with the Bees, which will in turn trigger the other light.

Canon EF 70-200mm f/2.8L IS USM

11/07/2005 03:22:54 PM · #8

OMG thank you for that article. Its long and dull, but gives me a FREE answer:

Another option is to tape over one of the data contacts in the hotshoe. Covering the lower left contact (the left contact out of the hotshoeâ��s group of four thatâ��s closest to the back of the camera when looking at the camera from the top) will disable all E-TTL functionality

Sweet!

And yes, I use the 420 to fire the Bees, my Bees didn't come with synch chord.

Mick

Canon EOS-5D

11/07/2005 04:22:54 PM · #9

Originally posted by idnic:

And yes, I use the 420 to fire the Bees, my Bees didn't come with synch chord.

You must have aquired them from a third party. I got a sync cord with each of my lights. A new sync cord (1/8-inch Stereo Plug to PC-connection) is only $7.95 from AlienBees.

If you'd like to go wireless, there are a lot of radio and infrared systems available. You probably won't find too many for $7.95 though. :)

Message edited by author 2005-11-07 17:04:38.

11/07/2005 10:29:52 PM · #10

I spent a few studio hours studying my problems tonight after getting such helpbul comments. The dual-flash with the FEL reallllllly works for me! It means I don't have to change anything, but get the results I want (downloading now, will post in a few).

I also ordered a synch chord for more permenant solution.

And yeah, I ordered my Bees from AB direct, but did not get a synch chord with any of the 3. Maybe they come with packaged kits, but I ordered parts as needed over time.