External flash AF assist beam problem (5D and 30D)

[lly3988]

I used a 90 Ex and 270EX on a Canon 5D (classic) and the 30D for the purpose of testing AF assist beam in low light enviroment. There isn't any burst of beams from the 2 flashes to assist in focusing on both cameras.

Both flashes are working well on 40D, T4i and 5D iii giving burst of beams when half press for AF.

They just won't respond when they are put on the 5D and 30D when half press the shutter button. Both cameras have no problem firing the 2 flashes when pics are taken.

I have enable the feature in the menu of both 30D and 5D and the batteries are fresh and work well on all other cameras mentioned. 30D built-in flash has no problem flashing AF assist beams.

I have also cleared the camera settings and custom settings. I used the same lens in AF mode in the experiment.

Both 30D and 5D are very old design. Is it a compatibilty problem ? Will anybody please suggest a solution or share their experience in this regard.

Thank you.

[TTMartin]

If you look at your 40D menu under the 2nd (middle) yellow wrench you will find 'Flash control'.

Upon selecting that you will notice there is a menu choice for Built-in flash func. setting and one for External flas func. setting as well as External flash C.Fn setting. 

Those External flash setting menu choices are what is needed by the 90EX and the 270EX, since they have no way of changing those settings on the flash itself.

Those menu choices are missing from your classic 5D and the 30D and are why they don't work with the 90EX and the 270EX.

And the difference between the 430EX and the 430EX II and the 580EX and the 580EX II is that the II versions of those flashes can be controlled by either with their on flash controls or the in camera menus. Where the original versions of those flashes can only be controlled with the on flash controls.

[lly3988]

Thanks. I am aware of the flash settings on newer cameras (including 40D - I mean newer than 5D and 30D)

These 2 flashes work well on 5D and 30D except that they are not fully compatible - cannot perform the AF assist beam. Menu choices are not missing but just cameras/flashes compatibility problem. 5D does have the menu and the camera has no built-in flash so it is definitely for external flash. When 05 is enabled or set to emits, AF assist beam is not fired.

[TTMartin]

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@lly3988 wrote:
Thanks. I am aware of the flash settings on newer cameras (including 40D - I mean newer than 5D and 30D)

These 2 flashes work well on 5D and 30D except that they are not fully compatible - cannot perform the AF assist beam. Menu choices are not missing but just cameras/flashes compatibility problem. 5D does have the menu and the camera has no built-in flash so it is definitely for external flash. When 05 is enabled or set to emits, AF assist beam is not fired.

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The 90EX doesn't have focus assist strobe on any camera, and the specifications listed on the Canon website for the 270EX shows it doesn't have focus assist strobe on those cameras. So everything is working normally.

Speedlite 270EX
AF Assist Beam

Intermittent flash firing system
Effective range:
At center: Approx. 13.1 ft./4m
Periphery: Approx. 11.5 ft./3.5m (in total darkness)
Compatible with model EOS 50D and later. Available via firmware update for: EOS- 1Ds Mark III, EOS-1D Mark III, EOS 40D, EOS Rebel XSi, and EOS Rebel XS.

[lly3988]

Thanks again. But 90EX does have the focus assist strobe. I have tested it on 40D T4i and 5D3 and it's confirmed.
Both of the 2 small flashes are okay as fill light on the old 5D and 30D. They have full compatibility on 40D and later (firmware update may be required for some as you say)
Looking to find a ST E2 or similar to see if the RED LED focus assist beam work on them.