Spot Mettering

[tommyalf]

The 30D is the first camera I've had with spot metering and as I've been doing research I'm not finding that much on how to use it correctly with the camera. First I'll admit I'm not sure I fully understand what it is and how it’s used. The manual doesn't do a great job explaining it and I've done a few searches online with little success. If anyone could shed some light on what it is and how to properly use it I'd greatly appreciate it.

Thanks
Tom

[E-Diddy!]

Instead of using the entire frame to meter the scene, the light meter uses only a portion of the frame (in the center). It can be useful for backlit situations, but i don't use it. I always take my metering from a grey card using evaluative metering before I shoot.

[Chris@YYZ]

I always take my metering from a grey card using evaluative metering before I shoot.

mind enlightening us?

[Airbus_A320]

I haven't used it either. I just leave it set to "center weighted average" and just kinda guess exposure compensation if it seems needed and use the histogram to verify. I have found that using centerweighted average, and evaluative give about the same exposure anyways.

But as Eric said, it's if you want to meter a small part of the frame as in a backlit sitution. I haven't used it at all on my 20D though.

[E-Diddy!]

mind enlightening us?

Other than having an incidence meter, grey card metering is the best way to get a proper metering setting. You hold it up perpendicular to your light source, bouncing as much of the reflected light into the lens as possible. The card only reflects 18% of the light that hits it, and because of this, it gives you an extremely accurate surface to meter, as it's uniform color and perfectly consistent reflective properties give your meter the best "picture" of the amount of light hitting the subject.

I've been using this method since the beginning of this summer, and I've found that in clear sunlight (pretty much half an hour past sunrise to half an hour before sunset), I always shoot at ISO 100 f/9.0 1/400th of a second. If it's a little cloudy, I keep the shutter open a little longer, depending on the amount of available light.

Also, when shooting backlit, I've found I get very nice results by just going up a stop in exposure.

Hope that helps!

[seahawk]

Spot metering uses a very tiny spot in the middle to ste exposure. Under normal situation it is useless for spotting.

[JordanD]

What situations would it be useful for? Eric said something about backlighting but I'm not sure what he meant exactly.

[seahawk]

I only found it usefull for rather strange shots. Like the inside of an engine or a shot using flash from inside an hangar facing the open door.

[JordanD]

I see. Definitely the type of shooting I do often or at all.

[tommyalf]

Thanks this has been very helpful guys!

[lmw]

Everyone has their own style of shooting, but in regards to this discussion, I do use spot meetering when photographing aircraft, however I shoot in manual mode.

Since I don't have a grey card, I normally use my camera's spot meter to meter of the grass (or the palm of my hand if I don't have a good grassy area).

This gives you a pretty accurate reading regardless of skin tone as our palms are all typically the same shade as far as reflective light is concerned.

Doing this provides me with much better results than any type of metering in an auto metering mode when shooting airliners.

If the sun is ducking in and out of the clouds, I simply adjust my shutter speed to compensate manually.