Okay here is something that I could not get my head around. I shoot with 5dmkii and always in manual. Most of time my meter is set to SPOT metering and point of focus is set to center point.
But thing that I'm having hard time getting understanding on is "locking meter" and than using that for different frame. e.g. If subject is standing near window and if I dont want to blow out details in light coming from window I should lock my meter on bright area and than point it back to subject's face and take a shot. But part that is confusing is how exactly this thing is done ? Is it even possible to do it if you are always shooting in Manual ?
If you are in manual adjust based on the face to get exposure as you like and recompose. But accept that if the range of the light is beyond the dynamic range of the camera you may have to choose between the person's exposing the person's face versus blowing out the window. The other option is to come back when the light is within dynamic range or use flash to decrease the image's range, or use an alternate technique like HDR.
What jerry told you is spot on (forgive the pun), Your options are:
1. Use a flash to balance the exposure
2. Use a reflector bounce light coming in back at your subject (YMMV)
2. Shoot an exposure for the face, then another for the windows and blend the exposures in photoshop using layers
There's just too much of a dynamic range difference between light coming in and the light falling on your subject. You wont' get it with one exposure.
In Manual, the meter is always "locked". Whatever aperture, shutterspeed, and ISO the camera is set to, that's it. It's "locked" into that.
So, point your spot at the desired tone, center the needle by adjusting aperture or shutterspeed or ISO. That is now "locked" for that tone. Compose your shot, focus, shoot.
Remember that meters try to make what they measure into middle gray. Grass is about middle gray in tone. Caucasian flesh is about a stop lighter, maybe as much as a stop and a half. So if you meter on caucasian skin tones, open up the aperture a stop or a stop and a third, or slow the shutterspeed by that amount.
Get used to pre-visualizing how light or dark a tone you want it to turn out in relation to middle gray. Sometimes you want to let sky blow out, sometimes not.
A really good exercise is to put your meter on average or center weighted, and then make a series of photos on a sunny day with sun behind you and between about 9 to 3 pm in summer (10 to 2 in winter).
Pose a friend in the picture. Have them hold a gray card if you have one (they are inexpensive) or better yet a ColorChecker set of colours. Have some shadow in the scene off to the side.
Meter the overall scene (not spot), and take a shot at the meter reading, both Raw and in-camera JPEG. Then make a series of Raw shots from -4 stops under to +3 stops over in 1/3 steps though the 1/3 steps could be only in the range of -2 to +2 if you want to save shots.
Then look at the Raws in your favourite Raw converter. Batch out a set of medium size JPEGs just as they are. Then take each Raw and try to adjust it in your converter for the best set of tones on the subject. Batch those out as medium size JPEGs. Compare and look at everything, comparing to the metered shot.
