What Metering do people mainly use for ease of use
Photographic equivalent of a sailor sticking a wet finger in the air to see how strong and which way the wind is blowing....
I LOOK at my scene.... (then like as not, shrug, and leave it on whatever is default in the camera, but that's another matter)
Phil, can you recomend a particular item that explains metering as i get some nice shots but the why escapes me? thanks Harvey
This is pretty useful:
Everything you need to know about exposure theory but were afraid to ask 101.
But, quick-bit; your 'meter' is measuring light intensity... & once upon a time we didn't have a multiplicity of choice over 'mode' metering mechanisms; we were lucky to have a meter! Even luckier if it was 'in' the camera.. so if we had one, we had to take a meter reading that was 'there or there a bouts' for the whole 'scene'.. an 'average'.. 'cos at the end of the day, we can only use, for one exposure, one shutter-speed, aperture and ISO combination...
BUT, some bits of our scene might be quite dark, some quite bright, and if we got the 'average' wrong, the the bright bits could white-out, or the dark-bits black out, or in between the mid-tones 'skew' from the middle and be too dark or too light compared to what we saw.
So, 'spot-metering'; rather than taking a measurement from the whole scene, or a wide area of the scene; you take a 'spot' sample from a tiny bit of it.. meter off something that's about 'average' and.. well.. same as taking a bigger area average really, you could still blow the high-lights or loose the low-lights... BUT, 'Multi-Spot'? Take more than ONE 'spot' sample.... you can meter just how brght or dark the high & low-lights are, the use the 'range' of meter readings to make some sort of mathmatical 'average' for the entire scene between.
NOW if you can imagine it; your Digital-Camera IS basically, a LOT of light-meters.. one for every pixel in the picture it makes.. 'cos the 'digital' bit.. digital camera doesn't record an 'image', it record a number.. three numbers actually, for each pixel, one for the amount of red, one for the amount of blue, one for the amount of green, in each pixel... but I detract a little... point is, you are holding a 'meter' that can, and in fact HAS to take millions of TINY 'spot-meter' readings to create the data-file that describes the picture it 'makes'....
Point camera at scene, then, and it has however many million 'spot meter' samples, for everything in the scene, high-light, low-light, mid-tone, the lot...
And it can use any or all of them to decide what might give the 'best average' between the highest and lowest.. because, we ca STILL only use ONE combination of Shutter, aperture and ISO...
So the 'meter-modes' are describing different mathematical manipulations to calculate a single 'average', to base the exposure settings on.
Back to my 11+ at school, (FAR too many years ago); but, from the 'data-set', you have the "max" (highlight), "min" (low-Light), difference between them is the "Range"; but then you have the "Median" which is the halfway point between them; the "Mean" which is all your data values added up and averaged by how many values you have; the "Mode" which is the most common value in your set of samples, a-n-d I'm too old for this stuff! BUT, lots of different 'sums' you can do, looking at a set of 'Data' to combine them and make a new value that 'sort' of represents the whole lot....
And electrikery is MUCH better at maths than I am.... and where I might struggle to 'average' a pair of spot-meter readings in my head.. micro-processor in your camera can do gazillions of complex computations in a nano-second; so can use any or all of the 'Samples' for the individual pixels, and come up with any number of different, and mathematically correct, 'averages', like the 'median', 'mode' and 'mean', depending on which program yo tell it (or the factory programmers told it) to use.
Whether any of them are 'more accurate' is mutable; the 'right' exposure is the one that makes your picture look most like you want it; you can very accurately calculate an exposure that looks horrible.....
SO, its back to the top, and LOOKING at your SCENE.... and judging
for yourself, from what you SEE, what YOU want; and whether the cameras 'auto' metering will give it you, or not.... and my original quip, most of the time, it will, close enough; almost irrespective of the metering program set a few layers down the menu's...
If not? Why not? The most common ones are that a scene is uncommonly light or dark; say a twilight scene, or a snow-scene, where the 'meter' is going to try and make settings to make the whole scene vary about an 'average' 1/5th grey mid-tone, and shifts the average up or down to make the entire scene brighter or darker than what you see; or you have uncommonly high contrast in the scene, where the camera might struggle to capture detail in both high-lights and low-lights at the same time, and different metering programs MAY be able to weigh these up and adjust the 'average' to a mid-point that better centres on the range... ASSUMING that is what you want...
So the trick is to know what is 'common', and where the camera will do all these fancy calculations to offer settings like as not to deliver what you want or expect; and what is 'uncommon', where it might not. and then the VERY tricky bit.... what to do about it!
BUT all starts by looking at your SCENE, not the settings on your camera.. you need to look through it, not it at it!