Spot Metering

[Slicker]

Hi,

I am looking to upgrade my 400D to a 50D in the near future.

I have a question about the spot metering function. My 400D does not have spot metering so I have never used it before. With the 50D and spot metering how do you select what "spot" to meter from? Is it always in the same place or can you move the spot around?

Thanks
Paul

[mart77]

you point the camera at what you want to meter, its basically like usign the center focus point to focus in the camera.

[Paulmack]

No with canon its usually 4% of the centre of the viewfinder.

So its a circle which expands just outside of the centre focus point. If you want to meter something that is to the left of the viewfinder then simply point the centre of the camera there then recompose the shot.

[Slicker]

so the spot meter is always on the center focus point?

[Slicker]

No with canon its usually 4% of the centre of the viewfinder.

So its a circle which expands just outside of the centre focus point. If you want to meter something that is to the left of the viewfinder then simply point the centre of the camera there then recompose the shot.


ok - that makes sense I think... thanks for the info.

[Paulmack]

Hopefully this will help

http://farm3.static.flickr.com/2578/3722661695_1b5abe482e.jpg?v=0

[Slicker]

perfect! :)

Thanks

[desantnik]

Remembering of course when you use it that the colour of the subject at that point will radically effect the exposure regardless of the general ambient light.

Eg, take a very bright sunny day in the desert and point the camera at the chest of someone who has a black logo on a white t-shirt and watch the exposure fall apart...

I know that spot metering is all about getting it right where you shoot, but just remember colours, in particular black, are degrees of reflected light....

[Paulmack]

http://www.thewonderoflight.com/articles/?page_id=104

This is an excellent read when it comes to spot metering

[sheddy]

<<<<<<<< but just remember colours, in particular black, are degrees of reflected light....

Black is actually an absence of reflected light and as such cannot be a colour.

[desantnik]

the thing sticking out of my mouth is my tongue

:-P

[redhed17]

so the spot meter is always on the center focus point?
I thought if you used a single focus point, then that would be where the spot meter took its reading from, and indeed the D300 manual, and Thom Hogan's D300 guide confirm this to be the case.

I assume it will be the same for other cameras. :)

[blue max]

Personally I don't really have a need for spot focus myself. Basically it is realistically only useful for carefully composed shots and even then you have to be able to use a bit of skill and judgement to spot a bit of 50% colour. And then I would just bracket and shoot in raw.

I am sure there are some who use it, but I would imagine they are in a distinct minority (ready to hear otherwise of course).

Graham

[admirable]

Well I might be wrong here but I think you can link the spot meter to the focus point that is in use or 'active' on a Canon.

I will check this out and report back later!

[desantnik]

As far as I know, the D300/700/3 and certainly later Canon 1D's have spot metering from the selected focus point, but on the Canon 30D I had it was "weighted around the centre, covering 3.5%" and thats probably true of all of the non-1D Canon's too.

Also on the D300/700/3 you can adjust the size of the "spot" too...

[DigitalRelish]

According to DPReview's review of the 50D (http://www.dpreview.com/reviews/canoneos50d/page2.asp),

Spot metering (approx. 3.8% at center)

Also, ePHOTOzine's 50D review (http://www.ephotozine.com/article/Canon-EOS-50D-10123) says,

Spot metering does the opposite of centre-weighted and takes a reading from the very centre of the image only using around 3.8% of the image.

[admirable]

Yep. just read the wee books on the 1D and 40D, it is selective on the 1D but not on my 40D!

[CyBeRkId2002]

Wow... This is quite a bit different to Nikon then... Im sure even my trusty old D50 spot metered from the currently active focus point and quite useful in certain situations it is too...

[DigitalRelish]

Wow... This is quite a bit different to Nikon then... Im sure even my trusty old D50 spot metered from the currently active focus point and quite useful in certain situations it is too...

According to DPR (http://www.dpreview.com/reviews/nikond50/page2.asp), you're right, it did!

Spot: Meters 3.5 mm circle (about 2.5% of frame) centered on active focus area

[HoppyUK]

Remembering of course when you use it that the colour of the subject at that point will radically effect the exposure regardless of the general ambient light.

Eg, take a very bright sunny day in the desert and point the camera at the chest of someone who has a black logo on a white t-shirt and watch the exposure fall apart...

I know that spot metering is all about getting it right where you shoot, but just remember colours, in particular black, are degrees of reflected light....

"the colour of the subject... will radically effect the exposure." :thinking:

If a colour reflects a certain amount of light, it makes no difference whether it is red, green or blue. Exposure will be the same.

[redhed17]

I don't think up to the 450D that Canons, at least the lower part of the range, had Spot Metering. They had, and still have, Partial which is not the same. AFAIK, Canon are the only manufacturer with Partial Metering, though I could be wrong.

According to Wikipedia
Partial metering

This mode meters a larger area than spot metering (around 10-15% of the entire frame), and is generally used when very bright or very dark areas on the edges of the frame would otherwise influence the metering unduly. Like spot metering, some cameras can use variable points to take readings from, (in general autofocus points), or have a fixed point in the centre of the viewfinder. Partial metering is found mostly on Canon cameras.

While Wikipedia may not be relied on 100%, that looks OK to me. :)

[Chaz Photos]

if you wish to take a reading not in centre you can point your centre spot and press the * button and then compose, focus and shoot

[Blue Eagle]

I find it is handy when you have a very bright area in a photo that you would like to be correctly exposed, while underexposing the rest of the shot. This is done quite a lot in fashion.