Canon 20D with 550EX

[shay_ohayon]

Hi All,

 

Short question - does the 20D handle E-TTL OK ? (i.e. 550EX) ?

In other words - is there a backward compatibility between E-TTL II

and E-TTL ?

 

Thanks in advance,

 

Shay

[oofoto]

Short answer is Yes.

[mark u]

The only difference between E-TTL and E-TTL II is what the camera body does, not what the flash does - the difference is merely in how the camera meters the preflash and selects the appropriate flash power to use. Any EX series flash will work with bodies that operate either system.

[robin_sibson1]

In my experience, the combination works fine. The only problem is that the auto zoom on the flash head sets it to cover what is needed for FF. That's a fail-safe outcome, in that it does not vignette but may waste a bit of flash power. The 580EX was advertised as handling this, but apparently the algorthm was implemented incorrectly and vignetting will occur with lenses wider than 24mm (actual, not equivalent). Haven't yet seen any reports of whether it is correct on the 430EX.

[carl_weller]

E-TTL II is a body function, not a flash function!

[steve_dunn2]

<p>A. Taner posted that crop-factor correction on the 430EX also appears to be broken, but IIRC, it's broken in a different way: it zooms to the lens' actual focal length, just as flash units which don't support this feature do. Very strange that Canon advertises this feature as something new and useful on their two latest flash models but didn't actually seem to test it to see if it worked before shipping them.</p>

 

<p>Back to the original: as others have pointed out, <a href="http://photonotes.org/articles/eos-flash/#ettlii">the difference between E-TTL and E-TTL II is 100% in the body and 0% in the flash.</a></p>

[jim_larson1]

You want to go completely nuts? I have only read of one person using a real live 430EX. This person reported the AF assist lights to not function properly with a 20D (gentleman used two different 430EX's. . .on two different 20D bodies -> After futzing in the store. . .he bought a 580EX)