550ex / elan 7 metering in different modes

[kc_cc]

How does 550ex ETTL flash work with different metering modes of the

elan 7 in:

 

-partial

 

-center weighted metering modes?

 

Which ones do you use for which situations.

 

Has anyone tried FEL with centerweighted? As the flash owner's manual

states that FEL only works with partial/spot modes I'm curious.

[bill_goldman]

The E in E-TTL stands for evaluative mode. All EOS cameras automatically revert to evaluative mode for metering flash exposures regardless of what is selected on the camera, except when FEL is used, in which case the preflash is measured using spot or partial (if the camera does not have spot metering), depending on the camera model.

 

Also, since ambient and flash are measured separately during the flash sequence, some camera models allow use of the selected mode for ambient measurements while others revert to evaluative. I believe the Elan 7 uses the selected mode for the ambient measurements but I am not sure.

[yakim_peled1]

<p> The standard link: <a href="http://photonotes.org/articles/eos-flash/">The EOS flash bible</a>. </p>

 

 

<p>Happy shooting,<br>

Yakim.</p>

[micheleberti]

<p><i>" All EOS cameras automatically revert to evaluative mode for metering flash exposures regardless of what is selected on the camera, except when FEL is used, in which case the preflash is measured using spot or partial "</i></p>

 

<p>R U sure? I thought ETTL was using <b>always</b> a center weighted average metering with a bias to the AF point. I am not sure but I think this is the way as it works almost on the 10D. </p>

[helen_b.]

An exposure measurement point can be combined, if desired, with an AF point being currently selected. However, 99% of people choose the central one due to its simplicity.

[steve_dunn2]

<cite>I thought ETTL was using always a center weighted average metering with a bias to the AF point.</cite>

 

<p>Essentially, this is what evaluative mode is on EOS bodies. CWA is exactly what it says - center-weighted, not AF point-weighted.</p>

[kaustubh]

do this test....

 

1. have a dark bg and a white subject...partial metering...make sure the subject is large enuff to cover the area of ur partial-metering....and not too large. don't put the flash on, set shutter speed to, say, 125 and do partial metering. check what aperture camera suggests.

 

2. now put the flash on and do the same exercise...same metering mode..same shooting mode...same shutterspeed. check if the camea now gives u a different reading. If it is, its most likely using evaluative...u might get a wider aperture...thats becos camera is giving weightage to the dark bg. if you get the same aperture, its sticking to partial.

 

note that camera does not change aperture-shutterspeed after firing pre-flash.

 

BTW, I always shoot in evaluative and hence never worry too much about this.

 

Kaustubh

[eosdoc]

Try not to confuse the issue. On the Elan 7E, ambient metering using

Evaluative mode exhibits

NEVEC behaviour (<a href=

http://eosdoc.com/manuals.asp?q=NEVEC

>http://eosdoc.com/manuals.asp?q=NEVEC</a>). Metering

of the flash lighting is completely different, and appears to be a

very tight spot rather than an evaluative pattern. See:<BR>

<a href=

http://eosdoc.com/manuals.asp?q=flashMeter

>http://eosdoc.com/manuals.asp?q=flashMeter</a>