Focus area and metering

[LBL2009]

Does focus area selection affect exposure results for the same metering setting?

For example, I set my metering to Matrix and choose any one of the three focus area. Will the exposure result the same?

D40 has three focus area - Closest subject, Dynamic and Single. Three metering selection - Matrix, Center weight and Spot.

If I choose Dynamic focus area and set the focus on the right focus bracket, can I set the metering to center weight or spot instead of Matrix? In other words, I focus on the right side of the subject and my metering is center weight or spot and this is OK?

 

[Rashkae]

Metering and focus are totally separate.

 

[daredevil123]

In theory matrix metering and focus point are separate.

But there seems to be a quirk to the D40, D40x and I heard some D80s too, that the focus point select do affect the matrix metering a little. I've read it on Flickr discussions and other websites. Ken Rockwell also claims so in his plain english guide to D40.

I read about how many users adapt to it, most of them using center weighted and their own SOP. Every camera model has its quirks just have to learn how it reacts to different situations and adapt to it.

For me personally, I use a D40x, I find exposure to be a little on the over-exposed side when using matrix. To get better results, I tend to do EV -2/3 or -1/3 most of the time. It depends on the situation as well as the lens I use. For example, when I use my 55-200 VR, it tends to overexpose more than the 18-55 EDII. I get the most problems on bright but hazy days. And especially when there is some glare, or the light direction is not behind me. The 50mm f/1.8D seems to be ok, but I am doing MF on that lens.

 

[daredevil123]

If I choose Dynamic focus area and set the focus on the right focus bracket, can I set the metering to center weight or spot instead of Matrix?

To answer this question. Yes you can.

 

[ZerocoolAstra]

hmmm I never thought about the focus selector affecting the metering.

So far I use center-weighted, and only move the focus selector if I am taking self-portrait with remote. Otherwise I leave it in the center, and use the half-press --> recompose technique.

 

[daredevil123]

hmmm I never thought about the focus selector affecting the metering.

So far I use center-weighted, and only move the focus selector if I am taking self-portrait with remote. Otherwise I leave it in the center, and use the half-press --> recompose technique.

By definition, Spot metering will meter the focus spot selected. Center weighted will do center of the entire frame irregardless of which focus point selected.

Using only the center focus point and recomposing is fine for most situations. It becomes a problem for me when I am doing shots with very shallow DoF for portrait shots. For eg., if I am taking a half body portrait shot using the 50mm f/1.8, I use center focus point to focus on the eyes, then recompose, sometimes that recomposing will cause the eyes to be OOF slightly. In situations like this I will switch the focus point to the one nearer to the eyes. It only matters if the DoF is very very shallow.

The quirk with D40/x by the way, is with matrix metering. Center weighted is no problem.

 

[daredevil123]

hmmm I never thought about the focus selector affecting the metering.

So far I use center-weighted, and only move the focus selector if I am taking self-portrait with remote. Otherwise I leave it in the center, and use the half-press --> recompose technique.

BTW ZerocoolAstra, I noticed you are using D80. What is your experience with matrix metering in D80? I personally have no idea since I never shot a D80 extensively before. But I read many complaints about the matrix metering in D80 is kinda weird and quirky. And it is very different from the Matrix metering with D70 D70s and D90. How do you find it?

 

[LBL2009]

Metering and focus are totally separate.

I see. So metering decides the exposure regardless of how we choose to focus. Am I right?

In theory matrix metering and focus point are separate.

But there seems to be a quirk to the D40, D40x and I heard some D80s too, that the focus point select do affect the matrix metering a little. I've read it on Flickr discussions and other websites. Ken Rockwell also claims so in his plain english guide to D40.

I read about how many users adapt to it, most of them using center weighted and their own SOP. Every camera model has its quirks just have to learn how it reacts to different situations and adapt to it.

For me personally, I use a D40x, I find exposure to be a little on the over-exposed side when using matrix. To get better results, I tend to do EV -2/3 or -1/3 most of the time. It depends on the situation as well as the lens I use. For example, when I use my 55-200 VR, it tends to overexpose more than the 18-55 EDII. I get the most problems on bright but hazy days. And especially when there is some glare, or the light direction is not behind me. The 50mm f/1.8D seems to be ok, but I am doing MF on that lens.

Yes. I find my pictures over-exposed and I always leave my metering at Matrix. Thanks for sharing the information with me.

 

[daredevil123]

I see. So metering decides the exposure regardless of how we choose to focus. Am I right?

Yes. Unless you selected spot metering, then the exposure metering will calculated at the selected focus point.

Also, exposure is recalculated when the shutter flips (i.e full press). So if you want fix the exposure then recompose, you can
1. Lock the Exposure when half pressing the shutter, you need to turn on the setting at Custom Menu #13 AE Lock.
2. Or, use the AE-L button - the behaviour determined by Custom menu #12 AE-L/AF-L

Yes. I find my pictures over-exposed and I always leave my metering at Matrix. Thanks for sharing the information with me.

No problem. We are here to help each other out.

 

[midicity]

By definition, Spot metering will meter the focus spot selected. Center weighted will do center of the entire frame irregardless of which focus point selected.

Using only the center focus point and recomposing is fine for most situations. It becomes a problem for me when I am doing shots with very shallow DoF for portrait shots. For eg., if I am taking a half body portrait shot using the 50mm f/1.8, I use center focus point to focus on the eyes, then recompose, sometimes that recomposing will cause the eyes to be OOF slightly. In situations like this I will switch the focus point to the one nearer to the eyes. It only matters if the DoF is very very shallow.

The quirk with D40/x by the way, is with matrix metering. Center weighted is no problem.

Spot metering at focus spot selected is for certain cameras only. I think the Nikon D300 and above has this, not sure about D90 & below. All Canon DSLRs 5d2 and below, that has spot metering, only has it at the centre focus point as shown within the centre circle in the Viewfinder

So if you want to spot meter on a canon 5d2 & below, you have spot meter off the centre circle in the Viewfinder, lock exposure, select focus point, click shutter

However, for Canon, Evaluative metering might affect metering at your selected focusing point