camera metering mode confusions (tips to avoid them)

Someone asked the question:

Just say someone (obviously not me!!) went out to take pictures in London for a weekend and took every single photo in center spot metering mode...
What would the effect be on the images taken ?

Answering this requires you to think about the cameras light meter and what it does. The meter just doesn't know what its looking at, you know what you're looking at but the meter just sees intensity. You know that its white, black or grey, the meter doesn't.

So where to meter? The whole scene? Just a bit? Some balance? Well it all depends...

If you put a white piece of paper on a black wall and meter off the white paper, will it be white? Nope, the camera will turn it grey (try it with your cameras spotmeter mode). This is the reason so many snowy scenes are turned grey by the camera (and why we have scene modes like snow or beach so that people don't have to think ... well except think to engage a mode ... so like that's not going to happen).

This is why in some ways we tend towards giving students grey cards.

Now, if you want the wall black or the paper white you can do one of two things: meter off the wall and adjust exposure (compensation) down to make it blacker meter off the paper and adjust exposure up to make it whiter (without blowing the sheet, put some light HB pencil marks on the paper and look for them) So if you were taking a stage shot with the stage in darkness (mostly) and an actor in the spotlight, then "spot metering" would make sense, mostly because the actor and costume will not be "white black or grey" but a balance.

So thinking about this walking around London with yoru meter set on spot will achieve what? On an overcast day the spot you select will be no different to the rest of the scene, or if it is (say a black london cab) then it will result in making that black thing grey over exposing the rest of the scene.

So in my view, when you don't have anything specific to meter off and any specific reasons. In the image below would I have got this result with spot metering where the red square is?

Probably not

I tend to work in this sort of situation in Manual and put metering on average (just for some sort of base line) and then once I've evaluated a few test shots tend to leave it just like that (unless what I see in the EVF in the post capture makes me change my mind. For instance the stage lights below would send a meter into confusion (although here spot on that 1 guy would probably work better).

Its hard to be certain because it could make some mistakes too (reflections of the instruments, the blackness behind), but stage work like this is where spot metering works better. Of course your exposures will all be rather different from each other compared to manual setting, and really the light of the stage didn't change that much (but when it does, keep looking at your EVF (or chimping if you're still using an optical DSLR finder).

Its likely that any automated metering would have just made my shots too dark or too bright, losing subtle textures and lighting which the artist desired.

So next time you go to a gig with your camera, think about this and consider having a go at manual.

Some things to keep in mind:

• modern stage lights are often LED and pulse very fast (so that your eye can't see it), but your shutter if too fast will occasionally capture frames which are inexplicably black ... this is why you see some movement of the artist in my shots because my shutter was set to 30th to always capture some of the "lights on" time.
• take manual shots and evaluate. Check for "blinking highlights"
• use manual light balance (not AWB) and check the screen till you get a result you like

I haven't seen "That 1 Guy" for a while now...


I like his earlier stuff better ...