Metering? Spot vs Matrix ?

[shadowlands]

I'm generally stuck in Matrix Metering. But I've messed with Spot Metering a little lately.
What is the "norm" for portraits? Is there a norm, and why?
Say you're doing a head-shot... spot would be the better option?
But if you're doing a group of four people, spread out... Matrix?
I may be off track. Seeking adivce.

 

[KmH]

Matrix biases the light meter by averaging all the light in the scene.

For portraiture Spot metering is much more precise for gauging the exposure needed for skin tones.
Note that with Nikon DSLR's the approx. 2% of the scene spot metered when using Spot mode is concurrent with the selected AF point.

For some portraiture situations Center-weighted metering may work better.
By the same token, in many portraiture shooting situations using a hand held light meter to measure incident or strobe lighting may be called for.
The light meter in the camera can only measure reflected light.

 

[Big Mike]

Above and beyond just averaging the light/reflectance of the scene, matrix may employ some fairly complex things...like color, object recognition etc. As far as I know, the companies like to keep the 'how they do it' pretty secret when it comes to their matrix or evaluative metering mode.
Just as an example, the matrix mode may recognize that you're shooting a person, and thus base a higher percentage of 'importance' on the part of the image where the person is. But it may also recognize how much of the scene is taken up by the person, and this may influence how much importance is given to the person vs how much is given to the 'background'.

Basically, they want it to be a 'smart' as possible, so that people don't have to really understand metering to use it. It's pretty much the 'dummy' mode that shows up in all their cameras, not just the DSLRs. On one hand, it often does a pretty good job. But on the other hand, when the camera is doing the thinking for you, you can expect to get results that you don't expect...if you know what I mean.

Spot metering, on the other hand, will read a specific spot (the actual size of the spot will vary by setting/camera/brand etc.) and it will ignore everything else in the scene.

So for example, if you are shooting a portrait and the background is significantly different than the subject, you will likely see a significant difference in the way that matrix meters the scene vs the way that spot does.

But either way...you need to realize that just because you meter on a specific spot, or take some sort of average of the scene....it's not necessarily going to get you 'proper' exposure. The camera's meter is calibrated to give you an accurate exposure, only if it is reading something that is the same tone as 'middle grey'. We commonly refer to 18% grey as middle grey, but I think camera makers have been shifting that value over the years.
But the point is that if you meter on someone's face...you may still over or under expose the photo (depending on how bright or dark their skin tones are)....unless you adjust your exposure away from the metered value. With a good understanding and enough experience, it's fairly easy to judge how much compensation you need to apply to your exposure.

Another way to do it, would be to use a grey card.
How to use a Grey Card ~ Mike Hodson Photography

 

[Derrel]

Spot metering demands extremely consistent technique. A small amount of mis-aiming, and the metering readings will be wildly influenced. Honestly, I have never been a fan of spot metering.

Nikon's center-weighted metering in the better cameras is adjustable. You know that scribed, 12mm diameter circle in the viewfinder??? That's something Nikon has used since the 1960's.

Go to page 112 in the D700 manual. Nikon describes center weighted metering as , "Classic meter for portraits."

Custom setting B5, on page 294, describes the different choices the user has in determining how large or small the center-weighted circle is. Options are 8mm, 12mm (default), 15mm, and 20mm, plus "Avg", for average.

 

[shadowlands]

Matrix biases the light meter by averaging all the light in the scene.

For portraiture Spot metering is much more precise for gauging the exposure needed for skin tones.
Note that with Nikon DSLR's the approx. 2% of the scene spot metered when using Spot mode is concurrent with the selected AF point.

For some portraiture situations Center-weighted metering may work better.
By the same token. in many portraiture shooting situations using a hand held light meter to measure incident or strobe lighting may be called for.
The light meter in the camera can only measure reflected light.

I appreciate you taking the time. Thanks for the better understanding.

 

[runnah]

Nikon's center-weighted metering in the better cameras is adjustable.

When I rarely switch off matrix I use this setting as spot is too finicky for my liking.

 

[shadowlands]

Above and beyond just averaging the light/reflectance of the scene, matrix may employ some fairly complex things...like color, object recognition etc. As far as I know, the companies like to keep the 'how they do it' pretty secret when it comes to their matrix or evaluative metering mode.
Just as an example, the matrix mode may recognize that you're shooting a person, and thus base a higher percentage of 'importance' on the part of the image where the person is. But it may also recognize how much of the scene is taken up by the person, and this may influence how much importance is given to the person vs how much is given to the 'background'.


Basically, they want it to be a 'smart' as possible, so that people don't have to really understand metering to use it. It's pretty much the 'dummy' mode that shows up in all their cameras, not just the DSLRs. On one hand, it often does a pretty good job. But on the other hand, when the camera is doing the thinking for you, you can expect to get results that you don't expect...if you know what I mean.

Spot metering, on the other hand, will read a specific spot (the actual size of the spot will vary by setting/camera/brand etc.) and it will ignore everything else in the scene.

So for example, if you are shooting a portrait and the background is significantly different than the subject, you will likely see a significant difference in the way that matrix meters the scene vs the way that spot does.

But either way...you need to realize that just because you meter on a specific spot, or take some sort of average of the scene....it's not necessarily going to get you 'proper' exposure. The camera's meter is calibrated to give you an accurate exposure, only if it is reading something that is the same tone as 'middle grey'. We commonly refer to 18% grey as middle grey, but I think camera makers have been shifting that value over the years.
But the point is that if you meter on someone's face...you may still over or under expose the photo (depending on how bright or dark their skin tones are)....unless you adjust your exposure away from the metered value. With a good understanding and enough experience, it's fairly easy to judge how much compensation you need to apply to your exposure.

Another way to do it, would be to use a grey card.
How to use a Grey Card ~ Mike Hodson Photography

Thanks... I have been doing portraits (full body and or head shots) in Matrix mode, always...
I will venture out into spot metering from time to time and see the results.

 

[shadowlands]

Spot metering demands extremely consistent technique. A small amount of mis-aiming, and the metering readings will be wildly influenced. Honestly, I have never been a fan of spot metering.

Nikon's center-weighted metering in the better cameras is adjustable. You know that scribed, 12mm diameter circle in the viewfinder??? That's something Nikon has used since the 1960's.

Go to page 112 in the D700 manual. Nikon describes center weighted metering as , "Classic meter for portraits."

Custom setting B5, on page 294, describes the different choices the user has in determining how large or small the center-weighted circle is. Options are 8mm, 12mm (default), 15mm, and 20mm, plus "Avg", for average.

I will indeed check that out. "Center Weighted" may be something I need to play with also.
Thanks Big Time!!!

 

[shadowlands]

Nikon's center-weighted metering in the better cameras is adjustable.

When I rarely switch off matrix I use this setting as spot is too finicky for my liking.

Matrix is getting lots of love today. Thanks!

 

[Derrel]

Nikon's center-weighted metering in the better cameras is adjustable.

When I rarely switch off matrix I use this setting as spot is too finicky for my liking.

I agree...I have found spot metering to be too finicky as well...it slows me down tremendously, and in Aperture priority auto, spot metering demands that the AE Lock button be used for basically, almost every frame fired. Nikon's center-weighted metering used to be one, fixed averaging value, with 60% of the metering weight given to the 12mm circle, and the remaining 40% spread over the entire frame. Then, with the F3, they went to a stronger center-weighting, the 80%/20% system, then it was back to the original 60/40 in a lot of the later bodies.

I 'suspect' that if one selects the Avg. setting in the D700, that it being a semi-pro/pro body, that the default metering will revert to either the F3 series mode of 80% in the 12mm circle, 20% spread over the entire balance of the frame, OR to the older 60/40 baseline that worked so doggone well.

When using flash modes, I think spot metering is to be avoided in probably 95% of all scenarios.

Using Matrix metering mode in MANUAL exposure mode does not make much sense either; Matrix puts too much emphasis on the whole frame. If you want to shoot MANUAL exposure, then use center-weighted for fast work, and spot for slow,deliberate, critical work. That's why the D700 has a three-position selector right back by the rear eyepiece; a dedicated control allowing the user to select the metering mode very quickly, to get the mode they want to use.

 

[shadowlands]

Nikon's center-weighted metering in the better cameras is adjustable.

When I rarely switch off matrix I use this setting as spot is too finicky for my liking.

I agree...I have found spot metering to be too finicky as well...it slows me down tremendously, and in Aperture priority auto, spot metering demands that the AE Lock button be used for basically, almost every frame fired. Nikon's center-weighted metering used to be one, fixed averaging value, with 60% of the metering weight given to the 12mm circle, and the remaining 40% spread over the entire frame. Then, with the F3, they went to a stronger center-weighting, the 80%/20% system, then it was back to the original 60/40 in a lot of the later bodies.

I 'suspect' that if one selects the Avg. setting in the D700, that it being a semi-pro/pro body, that the default metering will revert to either the F3 series mode of 80% in the 12mm circle, 20% spread over the entire balance of the frame, OR to the older 60/40 baseline that worked so doggone well.

When using flash modes, I think spot metering is to be avoided in probably 95% of all scenarios.

Using Matrix metering mode in MANUAL exposure mode does not make much sense either; Matrix puts too much emphasis on the whole frame. If you want to shoot MANUAL exposure, then use center-weighted for fast work, and spot for slow,deliberate, critical work. That's why the D700 has a three-position selector right back by the rear eyepiece; a dedicated control allowing the user to select the metering mode very quickly, to get the mode they want to use.

I'm generally in APERTURE mode. And I'm a TTL-BL-FP junkie and I think that may require Matrix... not sure, but I think it does.

 

[hirejn]

There's no such thing as a norm or standard for something that is as subjective as metering. Any and all metering methods work. It depends on how you use them and what works best for you. I use all of the metering methods you mention sometimes. My primary method is a hand-held incident meter, the Sekonic L-758. Hand-held meters can do several things that no camera meters can do. You could spend a lot of time fiddling with matrix or spot when a group is staring at you, taking test shots and adjusting, or you could click the 758 once and be done. The 758 doesn't care whether the subject is black or white. It just meters the light falling on the scene for perfect exposure, and any subject under that same light will be perfectly exposed regardless of reflectivity or tone.

 

[Big Mike]

I'm generally in APERTURE mode. And I'm a TTL-BL-FP junkie and I think that may require Matrix... not sure, but I think it does.

I'm a little foggy on how Nikon handles it's ETTL flash metering...but I have a somewhat less foggy idea of how Canon works...it may be similar. So with that said...

The metering mode (Matrix, centre weighted, spot etc) is for the camera's main (ambient) light meter. As far as I know, it does not influence the pattern or area that is read by the TTL flash metering system. The Canon system offers two options for TTL metering; Average or Evaluative. Average is just as you'd expect but Evaluative uses some of the 'secret' algorithms that the ambient evaluative metering mode uses. (Evaluative is the Canon equivalent of Nikon's matrix).
The default TTL metering mode is Evaluative, and I don't think many people ever take it off of that. There are some specific times where average would be a better choice...but not many.
I think it would be more common (certainly for me) to switch the flash to manual mode, rather than switch the TTL metering pattern/mode.

I know that Nikon has TTL and TTL-BL etc. I know they are slightly different, but I can't really explain (don't know) how they work.

Really, all of this trying to figure out what the camera is doing/thinking just boring and/or frustrating for me. I'd rather just put everything into manual mode, where I'm in control of what it's doing. That way, I can consistently get the results that I want.