Thursday, March 5, 2009

Sometimes you gotta let it go

So here's a picture of my two little boys rugged up and playing coits. The snow festival in Sapporo has three different event sites and this is the one at a place called TsuDome - which is the giant indoor stadium you can see behind you.

Pretty much all the activities happen outside. Giant ice slides, make your own snowman facilities and this traditional game.

Now the first thing that you'll notice is that it's nice and bright and the snow is white and everything looks fine - in particular if you looked at it on the back of your camera it would look great.

The problem occurs when you look at the histogram (which is why you never want to use your camera's LCD to judge exposure - only the histogram)

Here's a shot of the histogram in camera RAW. The bits that show up in bright red are the bits that are overexposed - beyond 255, no detail whatsoever. And if you look at this photo you'll notice that the entire sky is burnt out. Pure white. In actual fact the detail is there in the RAW file, but I have chosen to sacrifice detail in the sky to have a brighter picture.

If I had decided to keep all the detail in the sky, meaning the rest of the picture would be darker, this is what I would get. As you can see the sky is a pretty ordinary grey with a few wispy clouds. If I follow the rules I now have a picture where everything is within the histogram boundaries and nothing is too overexposed.

But it's a crap photo! So in times like this you need to make a judgement call as to whether you can afford to lose the highlights. Remember that the camera doesn't have the ability to retain as much detail as you can see with your eye. You're limited to only a few f-stops so you have to decide what to lose and what to keep.

Of course if I really wanted to avoid the problem I could just compose the picture so there wasn't any sky in it in the first place - a closeup. Often I do do that to avoid this problem but in this case I wanted to show where the coit toss was happening so chose to keep the sky.

So just remember to keep an eye on that histogram and try as much as possible to avoid having blown-out highlights. But be pragmatic and realise that it's not always possible. Sometimes keeping the highlights will mean the rest of the picture will be too dark. In those cases either crop the highlight parts out by re-composing the picture, or be prepared to lose them.

Wednesday, March 4, 2009

When you get a blow-out

No I'm not talking about an economic one, or even one of your back tyre. I'm talking about a blow-out of the highlights kind.

What does this mean? Ever since the time of the dinosaurs (well at least before digital came along) we all took pictures on film.

Professionals used slide film and a technique called exposing for the highlights. What this term meant was that you had to calculate your exposure so that the brightest parts of the picture weren't so bright that they would be lost.

With film, too bright highlights would just turn into clear film - nothing recorded whatsoever. With digital it's pretty much the same - the histogram reaches Level 155 and anything beyond that means there are no details whatsoever.

So why should you, or even should you, care? Because sometimes you want to retain detail in those highlights. Take the image of snow men above. This was taken on my recent trip to the snow festival in Sapporo. As you can see they are all very, very white. Indeed I intended it that way.

But more importantly if you look at this histogram in the top right hand corner of the picture you can see that it is buffering up against the right hand edge, but not falling off it. In other words if you zoom into any of those pieces of snow you can actually see the texture in the snow.

If I had tried to make the snow look even more brilliantly white (by making the picture brighter) I would have ended up losing detail in the brightest parts of the picture, and when the picture is printed on paper you would just get bare paper - no ink being laid down - in those too bright areas. Not a good look.

So this is an example of where you want to keep an eye on your histogram while you're photographing. It's a good idea to set your camera so that the histogram appears after every image, that way you can keep an eye on it. If your picture is too bright (histogram too far to the right) or too dark (histogram too far to the left) you can use your exposure compensation button to fix it.

Of course that's assuming you want to keep the highlights. Many photography books tell you to keep the histogram within limits at all costs - but sometimes that's just not possible or desirable. Tomorrow I'll show you an example of when you can let highlights go.

Tuesday, March 3, 2009

Still alive and kicking!

Hi there everybody,

I'm back from the frozen wilds of Japan! Actually I think my kids were the wildest things there but that's another story. :)

I photographed the amazing snow festival and will roll out some pictures over the next week or so to show you how it turned out. The weather nearly ruined everything as we had snow storms and blizzards every day the festival was on. I finally managed to get a clear night the final night of the festival.

Another major hiccup was batteries. My battery charger wouldn't work on Japanese power! It came complete with a transformer which I was assured would work on anything from 100V to 240V but alas that was just wishful thinking.

So I managed to survive on just two batteries - which don't last very long in freezing cold temperatures. So I would take a shot and then put the battery in my jacket pocket to warm it up and hope it kept on going. Of course being Japan meant that I could always drop into a mega-super camera store and pick up an extra couple of batteries but the way the Aussie peso is diving free fall against the Japanese yen I wanted to avoid it if I could.

Anyway this trip pretty much turned into an actual holiday. One thing you don't tend to appreciate as a travel photographer is a real holiday. You always tend to end up spending heaps of time photographing and fretting about getting the right light that you sometimes forget about the ones who love you the most.

So this 3 weeks was a chance to spend a lot of time with the wife and kids and not so much time working. So don't expect a glut of Sapporo photos (I've been too lazy to process any yet!) but there are certainly a few gems in there.