Spot metering.

[darktiger]

Okay I have had the 30D for a while, but do not really use spot metering. Am I missing anything. What uses does spot metering provide me? I understand the concept, but I guess I need examples of when to use it.........

[Jake]

Originally Posted by darktiger

Okay I have had the 30D for a while, but do not really use spot metering. Am I missing anything. What uses does spot metering provide me? I understand the concept, but I guess I need examples of when to use it.........

When some body or something is backlit you can spot meter on their face or just the object.

[laawaaris]

and what does that do? if you spot meter on their face what advantage does that give to the photo?

i shoot always in matrix metering, but last night tried Spot Metering - i didnt use it on a backlit subject but was a little confused on what spot metering was doing

i guess matrix metering gives equal weight to the entire photo - so the overall image is as properly exposed as possible?

but spot metering will give the most weight to the subject being spotted? so everything else may be blown out?

[Duffy Pratt]

For the sake of discussion, lets imagine you are shooting black and white. The scene will have tonal gradations from pure white to pure black.

A meter looks at an area of the scene and gives an exposure reading that will put the average for that area at a middle grey. (Typically this has been 18% grey, but there is someone who is challenging that idea and saying that in camera meters actually average for 12% grey.

With a spot meter, you are taking that average over a very small area of the scene. Skin tones can very often be rendered as the mid-grey. If you had a scene with a huge dynamic range, and you knew that you wanted the skin tones properly exposed, you could use a spot meter on the skin and then set the camera to that exposure to ensure that the skin tones would be properly exposed.

If you wanted to shoot a snow scene, and you wanted to make sure that an area of the snow still had some detail, you could use the spot meter on that area. Here, if you set the camera to what the spot meter read, you would end up with snow that was a middle grey. To make it look white, with some detail, you would most likely boost the exposure 2.5 to 3 stops.

Ansel Adams created a process for evaluating exposure called the zone system, which uses these ideas. Look at the link, for a simplified version of this system.

Duffy

[Comanche]

Originally Posted by darktiger

I understand the concept, but I guess I need examples of when to use it.........

Here's another example -

Being a 30D owner, I use spot metering a lot. In my case, I shoot a lot of high school sports, most of which are played at night under lights, or in gyms. In either case, the lighting is very poor, but spot metering will allow me to expose the subject correctly, whereas if I use matrix metering, the camera will try to figure how to come up with a correct exposure for the brightly lit subject and combine it with the dark background. The result will be a poorly exposed subject.



In this case, I exposed on the batter's shirt, which gave the pants a bit of an overexposure. If I had used matrix or averaging metering, the camera would have had to combine the bright parts of the composition (the players) with the dark background.

Hope this helps.

[Cope]

Originally Posted by laawaaris

and what does that do? if you spot meter on their face what advantage does that give to the photo?

i shoot always in matrix metering, but last night tried Spot Metering - i didnt use it on a backlit subject but was a little confused on what spot metering was doing

i guess matrix metering gives equal weight to the entire photo - so the overall image is as properly exposed as possible?

but spot metering will give the most weight to the subject being spotted? so everything else may be blown out?

Spot metering on the face in a bright environment will prevent shadows on the face. This normally won't blow out the background. blow out

Matrix metering works great when the entire framed area is fairly enely lit.

I usually shoot with center weighted average metering, and switch to spot if I have a high contrast situation.

[laawaaris]

Doug/Commanche,

Thanks for the tips. What do you think the image would have looked like if you shot it in Matrix Mode. The players are bright and the background is dark. Only about 1/4 of the image is dark and the rest is bright, so what do you think would have happened to the image as a whole?

[laawaaris]

hmm i re-read what you said doug

in matrix metering, the baseball batter would become poorly exposed

and the background would become a bit better exposed?

[Paulo]

Originally Posted by Duffy Pratt

...Ansel Adams created a process for evaluating exposure called the zone system, which uses these ideas. Look at the link, for a simplified version of this system.

Duffy

Great link. Thanks for sharing that Duffy.

Hi laawaris-
It'd probably look similar to this...not good at all. I should have known better but it didn't click. I shot this using matrix metering instead of spot on his face/skin. Image is of one of the fighers at the IFL tournament held at Reliant Stadium this past February.

[Paulo]

Originally Posted by pm-image

Great link. Thanks for sharing that Duffy.

Hi laawaris-
It'd probably look similar to this...not good at all. I should have known better but it didn't click. I shot this using matrix metering instead of spot on his face/skin. Image is of one of the fighers at the IFL tournament held at Reliant Stadium this past February.

But I felt that matrix did work though if the bright lighting was coming from the side or other angle besides directly behind the subject...

[JohnT]

Look at that "cauliflower" ear. I would not want to be on the receiving end of that guy's punches!

[Paulo]

Originally Posted by JohnT

Look at that "cauliflower" ear. I would not want to be on the receiving end of that guy's punches!

Yeah, it was good fight but poor fella ended losing by TKO.

Thanks for this thread, darktiger. I shot a wedding last Sunday and there were a few times, utilizing spot metering would have really helped.

[laawaaris]

cool shots!

i want to try spot metering now - but i still have to ask some really basic questions

when i change my metering to spot meter, how do i expose on the subject after that? when i look in the viewfinder there are 5 points of focus - and i can use the dial pad to change the focus from one area (top) to another area (right)

but to my understanding this is a focusing tool - is this what i would use to expose my spot meter on a particular subject?

also i've been reading this article on fredmiranda at: http://www.fredmiranda.com/A16/
in "Step 2" he says:
" it's a good idea to point your spot meter at various subjects to see how their tonal values
will be represented in the final image "

maybe my camera (Nikon D50) does not have the same capability at his, but how do you use the spot meter to see how the tonal values will be represented in the final image? to me, it sounds like he is saying you should point the camera, meter on a subject and only click the shutter half-way, then you look at some reading within the camera to see the tonal values and how they are exposed

i don't understand technically how to do this ...

[Cope]

Originally Posted by laawaaris

cool shots!

i want to try spot metering now - but i still have to ask some really basic questions

when i change my metering to spot meter, how do i expose on the subject after that? when i look in the viewfinder there are 5 points of focus - and i can use the dial pad to change the focus from one area (top) to another area (right)

but to my understanding this is a focusing tool - is this what i would use to expose my spot meter on a particular subject?


...

If the subject is a person or animal, focus on the eyes as always. With any other subject, focus as you normally would. I almost always use center spot focus (I guess the Nikon has a center button on the dial pad).

[Paulo]

Originally Posted by laawaaris

...
when i change my metering to spot meter, how do i expose on the subject after that? when i look in the viewfinder there are 5 points of focus - and i can use the dial pad to change the focus from one area (top) to another area (right)

but to my understanding this is a focusing tool - is this what i would use to expose my spot meter on a particular subject?....

also i've been reading this article on fredmiranda at: http://www.fredmiranda.com/A16/
in "Step 2" he says:
" it's a good idea to point your spot meter at various subjects to see how their tonal values
will be represented in the final image "

maybe my camera (Nikon D50) does not have the same capability at his, but how do you use the spot meter to see how the tonal values will be represented in the final image? to me, it sounds like he is saying you should point the camera, meter on a subject and only click the shutter half-way, then you look at some reading within the camera to see the tonal values and how they are exposed

i don't understand technically how to do this ...

I only browsed through my manual when I got my first digital so I could be wrong (no surprise) but when spot meter is turned on, the camera meters off that focus point.

When you're looking through the viewfinder after you depress the shutter halfway down, you see little bars kinda towards the bottom (at least on my D1X and N80). You'll notice a highlighted bar which is the way the camera is interpreting the scene as being either over exposed (hightlighted bar on the + side), nuetral (bar centered), or underexposed (bar on - side). Depending on what program (M, A, S,) you have it set to, when you place your focus points at different parts of the scene, either the shutter speed or aperture size will change. You note those changes when 'reading' differents areas of the scene and then either take an average so most will all come out or choose the main part of the scene you want to truly come out....

PLEASEEEE, someone correct me if I totally screwed this explanation up!