Spot Metering vs Center Weighted

So, it's Christmas morning and I'm trying to take a few not awful shots of the festivities. Pretty low light, so I have my Sigma 30/1.4 on the 60D. I'm using spot metering with center focus point right on face of subject. AV mode wide open. Auto WB; Auto ISO. Not thrilled with the results, so I switch to center weighted metering, which actually lights faces better. First example below is spot; second center. These are representative of what I saw on multiple photos.

What am I missing here? Shouldn't spot metering provide best exposure for face?

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Well, the problem with spot-metering is that it's ALWAYS dead center of your VF. Assuming you haven't done any cropping with the samples above... in the spot-metering photo... you metered on the white shirt.

Yes... metering continues despite half-pressing the shutter button. That's just how spot-metering works. What you needed to do was keep the center point on your daughter(?)/girl's face, then lock the exposure with the * button, and then you can move/compose your shot the way you did.

Your 2nd shot is better because you let your camera "see" a little bit more of what's around the girl. It's darker than her (and her shirt) and the camera compensated in an effort to raise the surrounding luminance to 18% grey.

In truth, as Julian points out, you "screwed up in reverse" but that's why #2 is brighter than #1.

Your camera always strives to attain medium grey (the metering sensors see only black and white). If it is center-weighted it finds the exposure that will make the average of all the tones in the frame medium grey, with extra weight given to the center area. If you put the spot meter on a face, it will calculate the exposure needed to make the face medium grey. But Caucasian faces are not medium toned, they are 1 to 1.5 stops brighter than medium. If you use spot meter, you must be ready to use Exposure Compensation to compensate for the difference between medium and the metered object. In this case, at least +1 EC.

You can also use the palm of your hand as a light meter. If you're light skinned, spot meter your palm in the same light as your subject and add that stop or stop and a half that tzalman suggested to the exposure. Manual mode would work best in this situation as you wouldn't have to fiddle with exposure lock or centering your subject in the viewfinder. After setting your aperture, simply meter your hand and roll the main dial (to decrease or increase shutter speed) 'til the meter in the viewfinder indicates the amount of overexposure you want to set.

Also, was the camera set to auto ISO? The first picture was ISO 100. The second, ISO 125. Higher ISO would have allowed a faster shutter speed to reduce subject movement or camera shake. The above metering technique will not work with auto ISO because the camera will adjust the ISO to center the exposure meter needle, negating your positive exposure adjustment.

I wouldn't be surprised if Evaluative actually performed better that Spot or Centre-Weighted in that situation. It seems to be fairly good at getting faces correct. It's also the only mode that works with focus points other than the centre one.

The way I use spot is to aim at what I want to expose and dial in where I want that area to fall on the histogram. Thats how I think of spot metering. The light meter in the view finder is your histogram.

Thanks for all the responses! Looking and thinking back I'm pretty sure that I lied in my OP. Pretty sure I was not using center focus point, and thus metering off the white shirt as jwcdds points out. The photos are SOOC uncropped, so that pretty much has to be the explanation.

It's pretty frustrating because I shouldn't be getting tripped up by DSLR 101 at this point. I need to better engage my brain when I shoot and make better decisions on the spot. I think I'll blame it on not shooting enough!

Thanks again for the replies.

mpix345 wrote in post #13604603
Pretty sure I was not using center focus point, and thus metering off the white shirt as jwcdds points out.

All metering modes, except for Evaluative, ignore your chosen AF point and use the centre one.

yeah i just finished a class (still need to learn more...) and i always use eval meter.. and the instructor had us use spot meter..

he said.. find the brightest item, find the darkest item, find the middle... as it should be close to 18% grey... meter off of that.. then pan around to the bright and dark.. your meter (if centered) when over the bright shouldnt be over 2 stops if so you will overexpose and not get it back.. so then adjust off of that.. if more than 2 stops on the dark you are ok as he has seen up to 5 stops down on dark is able to be recovered.. but possible noise...

i had a hectic time with my camera and trying to use what i learned this xmas...

did you shoot JPG or RAW? what did you use to edit?

i found to use RAW and edit with LR...

hope that helps for you to try....

side note.. thanks everyone else.. i didnt know spot meter only uses center AF.. instructor did not tell me that.. so does that mean this is why my son is not clear? i stood camera up in portrait mode and used far left AF point...

and to OP.. here was mine with natural light and no flash.. and all that other stuff...
http://www.flickr.com …571962899/in/ph​otostream/

Doesn't matter if it only uses center point, when in manual mode you aim, expose for what you're spotting off of and recompose Nikon lets you choose what AF point to use for spot though.

Tony Parenti wrote in post #13604868
Doesn't matter if it only uses center point, when in manual mode you aim, expose for what you're spotting off of and recompose Nikon lets you choose what AF point to use for spot though.

Does Nikon let you spot-meter with every single point? Or just a select few like the Canon 1D(s) series?

TeleFragger wrote in post #13604855
yeah i just finished a class (still need to learn more...) and i always use eval meter.. and the instructor had us use spot meter..

he said.. find the brightest item, find the darkest item, find the middle... as it should be close to 18% grey... meter off of that.. then pan around to the bright and dark.. your meter (if centered) when over the bright shouldnt be over 2 stops if so you will overexpose and not get it back.. so then adjust off of that.. if more than 2 stops on the dark you are ok as he has seen up to 5 stops down on dark is able to be recovered.. but possible noise...

i had a hectic time with my camera and trying to use what i learned this xmas...

did you shoot JPG or RAW? what did you use to edit?

i found to use RAW and edit with LR...

hope that helps for you to try....

side note.. thanks everyone else.. i didnt know spot meter only uses center AF.. instructor did not tell me that.. so does that mean this is why my son is not clear? i stood camera up in portrait mode and used far left AF point...

and to OP.. here was mine with natural light and no flash.. and all that other stuff...
http://www.flickr.com …571962899/in/ph​otostream/

In a lot of cases you are going to loose something so I usually spot meter the high end and the shadow and make a decision on where I want my tones to fall and what is important to keep and what I can let go and not hurt the visual statement.

Remember when using a spot meter that most light caucasian skin is one stop brighter than 18% gray is so if you do a spot meter reading of a white persons face and you fill the entire meter reading area is being filled by the skin tone and you want to render it as light caucasian skin then you will need to open a full stop from the meter to render it at zone VI because the meter sees the world as 18% gray of zone V.

If your going to be in the spot mode I would recommend shooting manual

That's correct. I almost always spot light skin caucasians at +1

after shooting for a couple years at Christmas with fast primes in low light, I decided this year to just attach my flash and bounce off the ceiling/walls with much better results, shooting at F2.8 and above.