A brief how too on using your camera'sfeature.
All modern cameras have a built into them.
Most seem to do the same thing with their various modes, and the type of lighting you are using will determine how the works too.
This info is about non flash/strobe photography only.
I have limited to no knowledge of flash photography and the way the camera is used in that scenario.
(anyone with extensive knowledge on that topic is free to add any info they want too)
Also, for those that find any concepts in this thread hard to grasp, feel free to ask questions.
I'll try to keep it as simple and understandable as I can.
From the little that I know of other(non ) brands, they all appear to operate in similar ways.
Firstly, camera makers seem to call their modes by various names.
use Spot, Centre Weighted and Matrix as they're three modes.
Other names for these can be Overall, Evaluative, Multi or Multi Pattern, Pattern, Partial, Zone, .. and probably a lot more.
Matrix is the same as Evaluative, or Multi/Multi Pattern, or Zone.
Some cameras have more than 3 different modes, for eg. seems to have 4, with a mode called 'Partial'.
What this is and does is something I know nothing of.
What is important is that you know and understand what each mode does.
For this thread tho, I'm going to stick with the two modes that I use most which are Spot(99.9%) and Matrix(0.1%) of the time.
Centre Weighted I occasionally use if I use the speedlight, which is rare in itself, so I may use CW mode 0.00001% of my camera usage.
My second priority is to help those that don't fully understand their system, and to try to explain how a camera is not quite smart, or as I prefer to describe it .. quite dumb.
We'll start with spot mode, as this shows more than any other mode how dumb the system is.
two images that clearly demonstrate this point are:
D800E_DSC_2014_0Ev_SPOT_BLACK.JPG ................... D800E_DSC_2016_0Ev_SPOT_WHITE.JPG
................ #1 Spot with 0Ev .................................. #2 Spot with 0Ev .
Two seemingly different exposures yet using the same control( more) and level(compensation set to 0), yet the exposures are wildly different.
As is obvious in these images with the red squares .. spot was read off two different colours, or as the system see them .. tones.
What's obvious is that in #1, the is taken from the black area and with 0Ev compensation, and #2 is read off the white area, with the same 0Ev compensation.
if the camera's was 'smart' it would know what I know, and that is that one box is black, and the other is white and take this into account and adjust itself accordingly.
BUT! it's not smart, and now I have to get off my lazy pain inducing posterior and do some of my own adjustments to the camera to account for it's lack of a brain.
it should be fairly obvious what needs to be done, but for those that are unsure, the solution is very simple.
When the camera's sees the scene, it really only sees everything more or less in black and white. That is a series of tones.
Apparently some, most or all Matrix settings take colour into account .. but from my experience(and is supposedly one of the better systems) it doesn't seem to understand deep blue skies very well.
matirx and landscape photography are a pair of concepts that work well together to drive me raving mad.
I think I may remember once where I used matrix .. and that my have been out of forgetfulness in returning back to spot mode.
So(trying to describe this part in brief) .. if I'm smart, and want to use (my preferred) spot mode, I have to set depending on the area that I'm off.
if I'm photographing people, I use 0 compensation, if I'm doing landscapes, I'm looking for either shadows or highlight that are important not to destroy.
If I'm not 100% sure which in landscape shooting, I off green grass and use about -0/7Ev(gets a more saturated colour rendering), or if yellow dry grass, anywhere from +0.7 to -0.7 depending on time of day and overall conditions. The point is I'm making my choice of based on the reading knowing how it will render the colour I'm most interested in.
These aren't hard and fast , and each camera model will even determine the amount of compensation I use. Higher levels also play a factor in this too. the higher, the more I tend to (set +ve compensation) .. but I still tend to prefer spot through all of this.
A bit of a gotcha to be aware of too.
Not all cameras systems work the same too. cameras will spot off the focus point you have chosen to focus with, so if you use the central one or if you use a peripheral focus square, they all still spot from that point. I've yet to come across a camera that doesn't work in this way.
But I've read that some cameras don't operate in this way( ) so if you're in spot mode, and want to use it, be sure to know how it works.
That is, if you're shooting portraits in a very dark(is. black) or bright(i.e. white) environment with a camera that doesn't spot from the chosen focus point(i.e. it spot meters only from the central point), and you are using a periphery point for focus of the person, then you would make the necessary adjustment to the to get the correct , or use an alternate mode.
Also note if you use manual the results can also vary wildly too ... but this isn't yet part of this writeup .. we'll save that for a later reply.
Now onto compensation and how to smarten up the system.
below are the same two images as above, the difference is that compensation has been set for one image to -2Ev (still in spot mode), and the other is set to +2Ev (in spot mode)
So in #3, as the red square is still set in the black area I set it to -2Ev, and conversely for the image with the red square set to the white area I set compensation to +2Ev.
As the only sees in terms of grey tones, with a 0Ev setting means that the camera will try to render that area of the scene as a grey colour.
if the were truly smart, even in spot mode! .. it would still use the colour matrix system to oversee the entire scene, make a determination that there are different tones(darks lights and mid tones) and then set it's own version of smartness to the setting.
As it is, this doesn't happen.
So by manually setting the compensation what I'm in effect doing is resetting the to tell the camera that this is a darker or lighter tone that it thinks it is.
if I don't set any compensation the camera thinks that I think it should be a grey mid tone.
The exact amount of compensation is not actually important, and even varies across different models from the same manufacturer. This is because of different sensor technologies, and the way the manufacturer decides is the best way for certain cameras to render the scene. These decisions could be to minimise noise/grain levels from certain cameras.
And also be aware that some see differently and transmit different amounts of through to the sensor.
But in the two images above, for #3 I set -2Ev compensation to tell the camera that this is a black area(ie. make it dark .. not grey as it tried to do in #1.
In opposition, for #4, I set compensation to +2Ev, which of course is the opposite direction in that I'm forcing the camera to render that white area white .. and again not the grey it did with 0 compensation.
(I hope this makes sense to those that are unsure).
There is another thread that talks about values or Ev levels. This is not the same thing.
These images are all shot under the exact same Ev. My dinky little study with those atrocious CFL lights that have terrible CRI values!
The only processing on these images has been to equalise WB to one point. WB variance has an affect levels to a degree too.
The Ev of the scene is between 5 and 6(1/3s and f/4 @ 100). This is inconsequential to the topic of the is post.
My use of compensation in the above images is to simply tell the camera that the tones I want rendered are not what it thinks they are.
Like I said the camera is quite dumb and doesn't know this(well at least cameras are!). I don't know what other cameras do(ie. Partial mode on Canons) so your camera may be different.
But in saying that, for many situations the camera's isn't as dumb as it may initially appear(or I thought it was)!
This next image is just about spot on, and when compared to the other two images that I thought were rendered just about spot on for their respective spot selection point Matrix mode at 0Ev compensation turned out quite well.
The way I understand this scenario is that the matrix chip/sensor saw the scene as both black and white and compensated for both tones.
's supposedly use a colour sensor for their matrix chip, but as I alluded too earlier, engineers may need a refresher course on what constitutes a deep blue sky scene!
So you would assume that this is the utopia that you were chasing. But I can tell you 100% for sure and without hesitation that this is far from the truth.
While it does an admiral job of trying to get a balanced , in this instance(#5) this was only true because the dynamic range of the scene was easily within the range of the camera.
FWIW, the last three exposures are well within a range that could be described as consistent exposures(about 1/3Ev or less).
Where Matrix fails(for me) is in the fact that it can vary so much between similar scenes. It makes no difference if that scene was a portrait or a landscape scene, I find too much variability of the exposures. Hence my preference to use spot for the majority of any photo shooting I do.
This isn't to say that Matrix is no good .. it may work perfectly for you, as will Centre Weighted .. that isn't the point of the thread.
The real issue is that you are reliant on what the camera engineers think makes up a good overall for the scene.
Go from a to a camera using a similar , and the exposures will most likely be different if you rely on matrix .
From my memory of matrix mode(years ago now .. it seemed to be more biased to protecting the highlight areas at the expense of shadow areas.
's also do this to a degree, but not as hard and fast as I remember the to do.
(no offense or derision is meant towards here .. this is just an observation I made from playing with a few cameras years ago .. it may well be different now anyhow)
Had a chat with a member a few weeks ago and one of the topics that came up was about and exposures. The idea of this topic came to me way before that as well, which was actually over a year ago as a response to a thread I've completely forgotten about somewhere in the archives of AP.
So the idea of this post is to help those that don't fully understand their camera's system, and the way it relates to control for a reasonable output.
Also note that this isn't the definitive how too on the topic of camera systems or and control.
It's meant as a (hopefully) simple way to describe as much as possible this topic, and hopefully to get those that don't fully understand it all to ask questions relating to their camera's .
The reason that this is important for many people is when they rely 100% on the cameras system to expose the scene.
And for those that think Manual mode is the only way you have true control over , they may have to think again!
This fact is only true if you also don't rely on the camera's for the !
That is, you shoot in Manual mode AND either use external lighting and or external meters.
if you shoot Manual and adjust the settings in the camera relative to the camera's .. you're not really using Manual mode. You're still relying on the cameras automatic for your shots!
Manual mode in this scenario only ensures that the cameras settings are consistent from one to the next .. for example if you are doing a multi shot panorama and other situations where consistent is required.
Hopefully, this thread will help some members to understand some of the concepts that are important in photography. isn't the only important concept, but once you have this technical concept under control, you can forget about it as something to concern yourself with and concentrate on the other aspects that create good photography.
Once you understand and (and even how your camera exposes and meters) ... it becomes second nature to you and you're free to think about other stuff.
ps. questions welcome .. and no question is to silly to ask. The chances are that if YOU are thinking of it others are probably wondering the same point too. So if you have any questions just ask.