5d Mark III - Metering Underexposed

[rjs1981]

So first off, I apologize as I think I've seen a similar thread here but I can't find it anymore!

I purchased a 5d Mark III as an upgrade from my 7d a couple of weeks ago and, although I am happy, there is one main issue that is bothering me.

When I meter a "perfect" exposure, the camera is delivering about a full stop UNDER that.

My normal settings are; 

Shoot in M

Center focus point

Spot metering

AI Servo.

I generally shoot 2/3 over anyway, and find that I'm needing to now shoot at least 1 2/3 over to get the same result as my 7d. In addition to that, I'm getting a noticeable vignette in lower (but even/consistent) light situations.

I have tried all the different metering options, including variations on the focus points. I have done a full factory reset and the issue is consistent across all my lenses. 

Any ideas?

[Hannahgivas]

Correct on the spot metering, but in my 7d in Evaluative metering mode, the chosen AF point is the active metering point. On the 5D mkiii it doesn't appear to be that way, and I'm still having a heck of a time nailing the metering on the 5D!! Very frustrating!! Any tips? Even when I have spot, meter of the center point, set exposure( in manual mode) and the recompose, I am not getting accurate readings! Almost always underexposed, also using other metering modes, same thing! What am I missing and why!!

[ebiggs1]

"... but in my 7d in Evaluative metering mode, the chosen AF point is the active metering point."

I sold m y 7D so I can't check it out right now but I think Tim is correct.  The metering point does not follow the focus point.  I don't think the mechanics are there to do that in any Canon body.

[Hannahgivas]

That is actually true with the 7d, and I have no issues metering with the 7d in evaluative metering mode, my issue is with the 5d mkiii

[ebiggs1]

Doesn't matter which body you are talking the metering is always going to be from the center.  The issue is how much.

[Hannahgivas]

I actually do not think that is true about the 7d in Evaluative mode, I have zero issues with metering with it, even if a highly contrasted scene, and my metering point set to the farthest outside point either way. It nails exposure for THAT POINT, even if much lighter or darker at THAT POINT!! Also when I first got the 7d, I was reading on this, and it is in fact true. However, I don't really want to discuss the 7d as I have no issues and am looking for help with the mkiii 😉

[cale_kat]

Metering for the crop-sensor 7D frequently meant metering within the prime center portion of a EF lens. Nice clean relatively balanced optics. Mount that same lens on a FF body, like the 5DMkIII, and now the lens has to work within the confines of the focal range for which it was designed. Yes, vignetting will occur with various combinations of lenses, lenses and hoods, etc.

As far as the metering "issue". I don't know what other sites are reporting but in my observation of numerous  most posts concerning the 5DMkIII have been positive. Optically, the 5DMkIII is probably putting your existing lenses to a more strenuous test of their capabilities. Generally speaking, the more capable the body, the more important the optics.

PS: I hope it won't bother Canon but I clipped the following from Overview page on the 7D... iFCL Metering with 63-zone dual-layer metering system uses both focus and color information to provide accurate exposure even in difficult lighting.

It sure sounds like the metering system can track and use focus information. Just saying...

[Hannahgivas]

"Overview page on the 7D... iFCL Metering with 63-zone dual-layer metering system uses both focus and color information to provide accurate exposure even in difficult lighting" I believe the 5d mkiii has the 63 zone, not the 7D :), off the topic of the 7D, the 5D mkiii is my problem, and I am having a heck of a time with metering with it! and using the selected AF point is absolutely useless! 😞

[cale_kat]

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@Hannahgivas wrote:
"Overview page on the 7D... iFCL Metering with 63-zone dual-layer metering system uses both focus and color information to provide accurate exposure even in difficult lighting" I believe the 5d mkiii has the 63 zone, not the 7D :), off the topic of the 7D, the 5D mkiii is my problem, and I am having a heck of a time with metering with it! and using the selected AF point is absolutely useless! 😞

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Good stuff here, http://cpn.canon-europe.com/content/education/infobank/exposure_settings/iFCL_metering.do including a picture of the 63-zone 7D metering sensor. LOL (I said I'd clipped it off Canon's web site.)

Camera has to meter through something. What lenses are you using?

[RobertTheFat]

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@cale_kat wrote:

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@Hannahgivas wrote:
"Overview page on the 7D... iFCL Metering with 63-zone dual-layer metering system uses both focus and color information to provide accurate exposure even in difficult lighting" I believe the 5d mkiii has the 63 zone, not the 7D :), off the topic of the 7D, the 5D mkiii is my problem, and I am having a heck of a time with metering with it! and using the selected AF point is absolutely useless! 😞

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Good stuff here, http://cpn.canon-europe.com/content/education/infobank/exposure_settings/iFCL_metering.do, including a picture of the 63-zone 7D metering sensor. LOL (I said I'd clipped it off Canon's web site.)

Camera has to meter through something. What lenses are you using?

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What isn't explained in that reference is how the 7D and the 60D map their 63-zone metering system onto a sensor with only 19 and 9 autofocus points, respectively. Incidentally, the URL you provided includes a trailing comma that must be removed in order to allow the link to be followed.

[TCampbell]

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@RobertTheFat wrote:

What isn't explained in that reference is how the 7D and the 60D map their 63-zone metering system onto a sensor with only 19 and 9 autofocus points, respectively. Incidentally, the URL you provided includes a trailing comma that must be removed in order to allow the link to be followed.

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The AF sensors are located on the floor of the mirror body (just below the reflex mirror).  The metering sensors are up in the viewfinder above (also, this is why we are cautioned to cover the viewfinder to get more accurate metering if our eye isn't blocking the viewfinder from stray light.)

Here's a diagram that may help (note: this is from a 30D):  http://www.imaging-resource.com/PRODS/D30/D30A3.HTM