Friday, 6 July 2012

What is it?

We sometimes come across beginners to photography who don’t “get it” as often as we come across newbies who take to photography like ducks to water.
  1. What makes a person not get it?
  2. What does not getting it mean? How does one tell? Obviously, the person who doesn’t get it is the one who can’t tell….
  3. How does one help someone see the light?
  4. Can you not get it and still enjoy photography?
Ming Thein on PetaPixel wrote an insightful article on Common Photographic Mistakes. For beginners he cites:
  • The missing subject
  • Poor perspective use
  • Being stuck in the wrong gear
But why do they do that? We know that’s what they do but why do some people do that? It is sometimes difficult for a veteran to time shift back to the days when the camera was new and experience was low.

The Missing Subject

If the subject is missing, the following could be the reasons:
  • The mind might already have taken the subject as a “given” – i.e. the photographer has already sighted, understood the subject but is unaware that the guest viewers have no pre-bonding and association with the subject. For example the subject could be so small in the scene and indistinguishable from the background that everyone else can see this issue except the photographer.
  • The photographer is not comfortable with camera settings and thus there is so much focus on settings and the camera, that the subject becomes completely secondary.
  • The photographer is trying to juxtapose elements of the scene – that tree, that road, that leading line or pattern that the subject is visually forgotten.
Bottom line: Understand what the subject is, understand that often (guidelines are made to be broken) there is really only one primary subject and everything else is story  telling and decoration (which are not unimportant, but they enhance the subject, they do not replace it).

Poor Perspective Use

Perspective with regard to the subject requires that the photographer first identify what the primary subject is and be aware that taking a photo of the subject means actually visualising what aspects of the subject – top, bottom, left side, right side, behind, overview, close-in the photographer needs to story tell.
Or rather, the difference between a photo that says “this is a picture of a man cleaning his glasses” and a photo that says “this is celebrity A cleaning his glasses in a thoughtful way as he muses on whether he should take the high road or low road” is based on story telling and perspective is part of the story telling.
You have to discover perspective. You have to move your feet with perspective and bend your knees and your waist and you neck up or down, side to side. Even if you have a zoom.
It’s way to easy for any photographer, beginner or veteran, to point the camera at the subject, optionally adjust the zoom and think “yup, that’s the shot, let’s do this”.
Way too often, we miss a much more awesome shot by just adjusting our position.
Cropping after the fact is sometimes the only technique we have to get the look that we want, but that’s an afterthought, and getting it right upstream often yields a technically higher quality image and potentially a visually more appealing angle.

Being stuck in the wrong gear

The camera not giving us the image when we click is the most common and annoying primary issue with all photographers – newbie or veteran. Why can’t all this high tech get into our head and just “make it so” like Jean Luc Picard would enunciate?
Actually, with the passing of each year, the tech is getting there. If you are not convinced, get your hands on a match needle film SLR of the yesteryear, shoot some shots in the city of people walking around pointing into the shadow in one shot, subsequently into the bright sun in another. Use a zoom lens with variable max aperture and it complicates it even more. Use transparency film with the classic lack of tolerance of exposure stuff ups, use manual focus lenses.
Then come up and use a modern DSLR camera with automatic smart scene detection, autofocus and do the same gig and see what happens to the number of relevantly exposed, correctly focussed shots.
It’s already there.
However, it isn’t what we expect still, because we raise our expectations every year. And we expect to shoot the human form against the sun and expect the camera to know whether we want a black silhouette or commendable flesh tones. – like as-if.
And if you came in from an auto everything camera phone or point and shoot compact, you expect the more expensive, purpose built camera to be whatever you were using, just more better.
Really to be successful in re-creating a dish you bought take away from an excellent food outlet, you can’t say to your food replicator “make it so"  - even in the notionally Utopian Star Trek, the food replicators need to be programmed to produce specific food. The same with setting up the camera to take a shot.
  1. You must visualise the shot
  2. You must de-construct the shot into the controllable elements
  3. You must figure out what techniques and settings in camera, in the lens choice and potentially in post processing, to re-construct the shot.
Food for thought.

Sunday, 10 June 2012

Exposure, the Metering Pattern and the Histogram

What is correct exposure?

What criteria do you use to assess correct exposure? Is it reading the histogram? Is it setting the camera to P A S and flipping to M to “match needle”? Is it buying this pro looking external exposure meter, then transferring the settings to the camera on M? Is it the way the photo “comes out?

There is no correct exposure. There is contextually suitable or relevant exposure. That means if you are wanting the face just right, it is. If you want the sky, it is. If you want that bright sky and that darker ground just right, well that’s being just…. greedy.

  1. The exposure histogram describes the brightness levels of the scene in numbers.
    1. It’s not a visual assessment. I’ll say it again, its not a visual assessment.
    2. It does not show whether the exposure is correct (see point 1 – there is no correct exposure). you can have what looks like a “good” histogram, whatever that is, but the face you want is contextually too dark or too light.. ditto with the sky and the earth.
    3. It can show that you are clipping highlights (255) or the shadows are going too dark ( 0 ). that does not mean you photo is “wrong” – it just shows that technically in numeric terms, you have lost digital data – that does not mean you have lost visual aesthetic.
    4. The averaged histogram may be misleading in technical terms. because your separate r g b channel histograms are different and one of them may already be clipping whilst the averaged histogram may not indicate that.
    5. There is more than one histogram for the same scene. Yes. There are:
      1. the Liveview histogram which is quickly computed so that the camera’s Liveview does not slow down. It is the stats BEFORE the shot is captured.
      2. the exposed photo JPEG histogram – this is the stats AFTER the shot is captured.
      3. the invisible and yet-to-be-deciphered raw file histogram. The reason why it is not visible can can’t be displayed is that the raw file has not been processed against your preferred set of contrast, saturation gamma curves. And if we did apply our preferences, it would no longer be the raw histogram, it would be the processed photo histogram.
    6. You might consider the highlight / shadow blinkies as an alternative to the histogram. But, the highlight and shadow blinkies give you even less information than the histogram – it can distract you by corrupting your perception of whether your exposure is contextually correct by painting your LCD with big blobs of red.
  2. You will often encounter naturally lit scenes that exceed the dynamic range of a single shot, even if you shoot raw. You will have to turn the tables (Star Trek’s Kobayashi Maru) by any trick – come back another day / season / time, stand with the sun behind your back, carry out exposure blending from multiple exposures, big a bigger sensor, shoot film).

Generally, we have:

  • Spot Metering
  • Centre Weighted Metering
  • Evaluative / Matrix Metering

Spot Metering

It tries to make anything you point at, 12% grey in tone. Point it at a white shirt and it will try to make it grey. Point it at a black shirt and it will try to make it grey.

That’s not a general use, point and shoot metering pattern. Some people figure they can use it like this, well and good for them.

Centre Weighted Metering

Centre Weighted covers a central area – yes, around the centre AF spot. The area may be hard edged. Or not. On optical viewfinders you may not be able to estimate how big the area is.

It has sufficient area that if you point it at something, it will average that bit of face, that bit of shirt and that bit of background to 18% grey. That might be just what you want – the face might turn out alright.

It has a small enough area to exclude the bright sky or that dark table shadow from dominating your camera’s exposure proposal.

There is also on some cameras, a spot biased centre weighted choice.

Matrix / Evaluative Metering

You could get the meter to measure the whole scene and take a dumb average. If you do that, some bright sky could “pull” the meter reading quite unfavourably towards a darker exposure.

So the camera makers came up with Matrix / Evaluative. Some cameras even have computationally enhanced evaluative (with elements of Artificial Intelligence, database statistics on image scene modes, face detection etc…)

This is the metering pattern (well it is not a pattern, it is a tremendous state of the art calculation) that the camera makers put a lot of their skill and knowledge into. If there is one thing they can create to help the millions of customers who just want to aim and press the trigger, this is the epitome of technological prowess.

So far on my cameras which are not leading edge nor are they the most expensive, this form of metering still can’t make it happen for the majority of my shots. Yet. And I can’t predict in which direction and by how much it will bias the camera’s setting since it is using some dynamic logic, not a standard pattern.

The Bottom Line

I have met a whole bunch of amateur photographers of various experience levels. And encountered even more on the web and in forums. Using my preference – Centre Weighted and the subjects I shoot, let me put forward some advice:

  1. Each country (e.g. Australia, Malaysia), each season (blue sky summer, gauzy overcast winter) and each time (Golden Hour, mid day, etc..) merits different consideration and care.
  2. There is no set-and-forget. And there is. Depends on your style and what you approve of and accept. You can accept that, for example, Street Photography of strangers cannot be controlled and is an unrepeatable point in time so any shot is good, even a technically imperfect shot. Or you can put on your grumpiest attitude and criticise the hell out of every landscape / panorama shot.
  3. These are modern cameras. Centre Weighted should be predictable. I didn’t say what you want (who knows what you want?). But it should be predictable. On a “standard” scene “what is standard?”, it should either be pretty close to good, or within 0.7 dark or light. If it is too dark or light, remember how it behaves and set the bias semi-permanently. It is semi permanent because there is no standard scene.
  4. Learn to identify several types of scenes. Why? Because that is what the camera makers are also doing for point and shoot people – that mechanism is called SCENE Modes. I’m NOT saying you should use SCENE mode. I’m saying you need to identify the scene you are pointing at, test it out beforehand how your camera’s Centre Weighted Pattern predicts and develop your own exposure biases so that they become instinctive and intuition.
  5. If you are using an EVF / LCD mirrorless camera, it’s even easier. Set your Liveview to exposure simulation mode (they’re already defaulting to that) and point, assess the darkness / brightness of the scene and flick your Exposure Compensation Dial. Just like that.

Further Reading

Sunday, 3 June 2012

An irreverent take on 50 Photography Tips