Tuesday, 17 April 2012

Grey days and bright skies...


Nikon D700  F/16  1/30s  ISO-800  PrSH  EV-0.7  90mm
...and what to do about them

Here's a very simple couple of manips if anyone's interested. I collect boats, you see.

No! Not real ones, silly, picture ones, as the boat is the symbol of Paris and once you become aware of them, like when you decide to buy a certain model of car, you start to see them everywhere.

Like here. This is the first one I've seen like this, very bas-relief barely scratched into the side of a fountain in a tiny Paris square just next to the Institut de France (see dome below).

So anyway, you can see it was a grey grey day. Or was it? Because my eyes didn't see the boat at all like in the  picture above. They saw it far more like the creamy beigy second picture. What had happened and what did Nikon let me do about it?

The answer's very straightforward once you understand some basic ideas. The funny thing is, our eyes are very sensitive to light and our brains very clever. What we're practically unaware of is that the actual colour of light changes depending on whether it's sunny or cloudy, sundown or high noon and so on. Night would also be a pretty clear example of this concept!!!
Nikon D700  F/16  1/30s  ISO-800  PrSH  EV-0.7  95mm
The day I shot the above picture it was cloudy and grey. When you think about it, maybe we aren't so unaware of changing lighting conditions after all, at least subconsciously. The day is 'grey' because the colours look washed out without direct sunlight to brighten them up. Bizarrely, there are some situations where colours can actually look richer when the sun isn't actually shining on them, but that's for another time!

So the point is, the camera can't compensate for this the way our brains can. I was still seeing a fairly beige and warm looking stone, but look what the camera saw - grey in all its gory glory!

Nikon D700  F/13  1/30s  ISO-800
PrSH  EV-0.7  32mm
 
Luckily we can compensate for this by telling the camera that we are shooting under specific conditions, in this case fairly thick cloud. And lo and behold, it 'warms' up the image for us, make injecting back some colour and making it look nice and almost sunny as in the second picture above. But let's not rejoice so quickly. Just when I thought I'd resolved all my photographic problems for the afternoon, along came another one straight after, just like buses.

Not liking the straight-on angle much I decided to squat down and lift my lens up to get in the sculpted head and stone rosary thing above the boat. Guess what happened next...

I got the result you can see on the left. A dark dark picture, which is strange, because the day was grey but not that gloomy, I assure you.

We're victims of another of the camera's limitations which it's vital we're aware of if we're not to waste time and shots with this sort of problem.

The camera doesn't know what we're pointing it at - how could it - so, to simplify a little, it always tries to average out the dark bits and the light bits so there's some detail in both of them. Unfortunately, again, film or even electronic sensors are far less capable than our eyes are of perceiving all the nuances of a scene in one go. The camera therefore simply averages out all the light and dark bits it can sense and exposes for the middle of them. That normally works well in an average scene with light bits, dark bits and mid-toned bits. The problems arise when a scene is predominantly dark or predominantly light.

Nikon D700  F/16  1/30s  ISO-800  PrSH  EV+2  24mm
Very light scenes will be 'averaged down' (made darker) and even the whites will end up looking like grey. Very dark scenes, conversely, will be 'averaged up' (made lighter), and all those nice rich blacks will also turn a murky grey, which isn't what we want at all.

In the scene above can you easily see what's happened? Not only is the statue very light - much lighter than an average grey between black and white, but almost a third of the picture is almost pure white sky. The camera 'averages down' the exposure, the sky turns a light grey, and the statue moves way down the scale into mid and dark greys well on their way to black. Oops.

There are several solutions to this problem, which I won't go into here, but they involve taking readings from specific part of the scene, using spot metering and my favourite of all, using the +/- button, my favourite button on the whole camera, barring the shutter release!

This final pic shows the dome of the venerable Institut de France I mentioned below, along with the same problem of under exposure for the same reasons. I've got no idea why I was on shutter speed priority down at 1/30 of a second! I can guess though, and in retrospect this accounts for the weird settings on all these shots now I come to think of it; I'd probably been demonstrating some blurred effects using a low shutter speed priority and forgot to switch back to my usual settings - sh*tt*r happens! And even though it was exposure compensated to plus two it still underexposed, also risking camera shake at that speed - a potential disaster all round, in fact. Luckily the wide angle at 24mm helped save it to an extent.


Above is a quick attempt (five minutes of some very basic adjustments) to sort this out after the event without making it look too unnatural. Far better, though, would have been to expose it properly in the first place. Which should always be your aim. Pretend you're shooting film (if you're not) and think that  you'll be wasting the price of the film and the processing costs if you mess it up. It's a great discipline.


And why not...
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* Sab Will runs Photo and Curios Tours in Paris, and also manages a variety of Paris and photography-themed sites and blogs. He writes an illustrated Paris Chronicle every day, runs a Meetup group for Paris lovers, interviews Paris personalities and reviews Paris books (on this blog), and even contributes to the city's street art (shh), so feel free to browse some of the links below and in the right-hand column to find out more about what he gets up to out there...

                        
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© 2012 Sab Will / Paris Set Me Free - Contact me directly for photo tours, interviews, exhibitions, etc.

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