Now that we have moved away from full auto mode and the presets in our camera challenges, there are a few things that we need to consider apart from the aperture and shutter speed in order to ensure a good photo.
The first thing you need to consider is the metering that you have set up. Metering is where the camera reads an area within your photo and decides how much light is being received there. In Aperture Priority and Shutter Priority modes this then determines the automatic value being assigned, so for example if you are in Aperture Priority mode and have an aperture of f5.6 and an ISO of 100 on a nice, sunny day, it may decide to set your shutter speed to 200. This is where the 50 shades of grey comes in.
Your camera assesses everything in shades of grey when it comes to exposure, and its absolute ideal is to make the point being metered reflect 18% of the available light to make it come out a nice, mid grey colour. Now this is all well and good it the point being metered is a nice mid colour to start with, but if it isn’t this leads the camera to make poor exposure decisions.
Take this photo, for example:
Now I can tell you that this is a photo of a piece of white knit fabric, but the camera, in Aperture priority mode, has rendered it as a piece of grey knit. In this case the problem is that I focussed on a white area, and my metering is set up is geared to look at my focussing point more than anything else to evaluate the amount of light being reflected. Going back to the camera wanting everything at perfect exposure to be a nice, mid grey, it has indeed turned my white fabric into a nice mid grey! You’ll notice that the background is also a shade of grey or two, and nothing is a nice, crisp white.
At the opposite end of the range we have this:
This is a pitch black lens. No really, it is, but again my camera has gone to great efforts to make it into a grey lens.
So how do we make sure that we don’t get our photos in 50 shades of grey? Well there’s a couple of options:
- Choose an appropriate metering mode. Looking at the 2 main DSLR manufacturers we have the following choices:
|Evaluative Metering||This looks at the whole scene, but prioritises the focal point||3D Colour Matrix||This looks at the whole scene, but gives priority to darker areas to prevent underexposure|
|Centre Weighted Average Metering||This looks at the whole scene, but prioritises the centre of the screen||Centre Weighted Average Metering||This looks at the whole scene, but prioritises the centre of the screen|
|Partial Metering||This uses around 20% of the centre of the screen to meter from||Average Metering||This takes an average across the whole scene, so very bright areas can effectively skew the results|
|Spot Metering||This uses what is immediately around the centre focussing spot on the screen||Spot Metering||This uses what is immediately around the centre focussing spot on the screen|
You will see that while some of the options between Canon and Nikon are the same, others are not, so have a look in your manual to see what’s available for your camera.
- Adjust your exposure. In Manual mode you completely control the exposure, however in Aperture Priority and Shutter Priority modes you will need to give the camera a nudge in the right direction by using Exposure Compensation to fool it into thinking something is darker or lighter than it actually is. There is usually a symbol for this which is a +/- sign, but look up your camera manual to find out where yours is.If your photo is of something which is mean to be white, you will need to go for a positive exposure compensation. For something which is meant to be black, you will need to go for a negative exposure compensation.Here is our white fabric again:
And our black lens (note the white background is mid grey). Hmm, maybe you want to up that exposure a wee bit, but let’s not end up with something that doesn’t resemble black at all…:
Now that you’ve got the correct level of exposure, your next challenge is to make sure that the colours come out correctly. One of the things that I see people complain about most is the fact that the colours in their photo aren’t true to life – this is due to the type of light shining on an object. It’s not just cameras that get this wrong though, just think about how you’ve bought something in a shop thinking it was one colour, and then gone outside to find it was another shade entirely (and I don’t mean that blue and black dress!)
The blue and black dress does serve to show something though, since the main problem was that the photo had terrible white balance (in case you’re wondering, I saw blue and black, but then I did another colour test and discovered it was because I have an extra set of cones in my retina, and apparently those of us with that extra cone saw it perfectly well, even if the first thing I may have said was ‘that’s a terribly processed photo’)
Anyway setting the white balance for your camera works in two ways:
- By you telling the camera that you are in a certain light situation – eg fluorescent lighting – the camera knows that the light from fluorescent lighting is on the blue side, so it adjusts the colours within your photo by reducing the amount of blue.
- By you telling the camera that something in your photo is white, so it then adjusts the other colours in the photo according to how offset the white is along the red, green and blue light spectrums.
Option #1 is the easiest to set up in your camera if you know that you’re going to be in a certain lighting setup but taking photos in different places, eg working your way round a party taking photos of different guests, all wearing different colours, but all under the same tungsten light bulbs. Have a look in your camera manual to see what options there are available.
Option #2 lets you set a custom white balance. This is worth doing if you’re going to be fixed in one place to take a series of photos, eg a table top photo shoot of items to go into a shop. For this you simply pop a piece of white card or paper so that it fills the screen and then follow your camera manual to set the white balance from that. Every photo you take while on this setting will then have the same white balance, giving consistency across the shoot.
I will admit that I usually use ‘auto’ white balance, but then I also take my photos in RAW format which means I can adjust it at the click of a button when I’m processing them later (we’ll get back to RAW in a few months!) Auto is not awful, but it’s not always that smart either, so it’s worth it to try and choose the appropriate lighting option for your location.