Exposure sweet spot
Exposure sweet spot
The wilds of Kintail

It’s always good to go out on a photography expedition, following faint tracks across the hills and on to wilder places beyond the reach of the hordes. Even the tracks are crowded these days, with almost sixty people packed onto the Blaven path the other day. I’ve never seen that many and neither have I seen eight ravens circling the summit. A mark of how many people were up there. If I’m on expedition I like to lug the Nikon kit, tripod and filters and sit and watch the light, changing lenses to suit my mood and respond to things that appear in the landscape. But there’s also a place in photography for the found image. The image that appears and disappears in an instant and where there is no time to setup, sort lenses, compose and shoot from a tripod. It’s gone. Found images are everywhere if you look with a keen eye on the landscape but it’s not always practical to carry full photography kit to record them. The other day I was out on the bike in Kintail, escaping from the hordes and finding quiet time round the back of the mountains. A photographer always carries a camera and today I had the wee Sony RX100 Va. A cracking little workhorse that I use in aperture priority mode but as it has a tiny sensor its dynamic range isn’t as wide as the Nikon so it takes careful consideration of a scene to make sure the exposure works. To that end I’ve been using this technique for years on small cameras. I call it Expose ’n Compose. It’s great for found images and dealing with dynamic range that’s too much for the camera when it’s not in auto mode.

I’d stopped for a look up the glen when the clouds parted and sunshine broke through so I took a couple of images to compare the exposure to see what the camera was doing with the raw data. The light then moved on as did I. In the first image I just pointed the camera straight into the scene. I wasn’t too bothered about composition, just exposure and the camera was set to aperture priority at f9 and shooting in raw.

In the above image, which was a straight exposure looking into the scene there is plenty detail in the foreground but the sky looks rather dodgy. They say you can recover lost detail in post but sometimes it can result in odd colour shifts as Lightroom apparently guesses what pure white should be when it encounters blown highlights and in this shot, the highlights are most definitely blown. The “recover in post” mantra for dealing with highlights really doesn’t work with small sensors in my experience. You really have to get it right in camera when you’re off auto as the lack of dynamic range can cause pretty serious clipping and loss of detail to such an extent it can mean loss of image.

To put this in perspective, I normally shoot with a Nikon D5500, which is a superb, affordable, user friendly camera with a dynamic range of around 14 EV according to DXOMARK. Recovering in post can work with this camera and I never need to use the Expose ’n Compose technique with it. However, the RX100 Va has dynamic range of around 10 EV according to DXOMARK, which although still impressive, isn’t as wide as the Nikon and the light can sometimes get the better of the 1 inch sensor. The above shot is an example of the scene’s dynamic range running rings round that small sensor.

Exposure meters all work the same way. They make a scene 50% grey. Simple. They don’t recognise clouds or water or snow or anything. They just see numbers and try and make them all grey. In the above image the meter has boosted everything, pushing the sky over the limit and blowing the highlights. The image is lost. There’s a 70% difference in light between the foreground and the sky so when the meter greys everything, that small boost is enough to push the highlights beyond recovery.

In the second shot above, I kept the camera at f9 but pointed it up about a third above the centre point of the previous image and half pressed the shutter button. I’ve set up the camera to cause it to lock the exposure when I do this. It also locks the focus but that’s fine in landscape shots as everything is essentially in focus at this aperture and distance. The key point is the image is now exposed for the hightlights. I then moved the camera back down to the original composition and fully depressed the shutter button. The result is much better. The 70% difference is still there but the meter has gone the other way, pushing the data down towards grey rather than up. The foreground is too dark of course but that’s easily fixed in post. The sensor, at 80 ISO, isn’t noisy in the shadows so lifting the exposure there is fine. Overall, there are around 1.5 stops of difference between the foreground and the sky. The reason the technique is easy and useful on the Sony is down to the real time feedback from the viewfinder. I rarely use the back screen but prefer to use the pop-up viewfinder. It’s like having a mini darkroom where I can experiment with different exposure settings. I just have to make sure the shutter speed doesn’t get too low and if it does, nudge the ISO up until it’s back into hand-held territory.

Back at the computer, for that is where we always end up in photography these days, processing data long into the night in some cases, I did a quick exposure drop on the first image but the sky was completely blown out. No amount of tweaking would recover the blown highlights.

For the second image, to “recover in post” first I increased global exposure 1.75 stops to match the original image and bring the foreground detail out. I could have worked on the bottom and top halves of the image separately but I thought I’d boost the exposure globally to see what I would have done had the first image been workable. I added a graduated filter over the sky and background, dropped the exposure 1.75 stops to match the in camera exposure, boosted the whites, dropped the blacks and added some texture. I then added a second graduated filter for the foreground and added some texture and tweaked the blacks and highlights to suit my taste. I also added a small radial filter over the right background, dropping the exposure there by half a stop as it was too overpowering for such a small area of the image. I could have avoided all this data processing work but using auto but it would have chosen the ISO and aperture and the camera tends to like more open f-stops when used in auto, leading to less depth of field. Imagine if we had a digital Claude Glass we could manipulate with a finger? Brushing vision over the scene as we stand in front of a majestic natural phenomenon, creating a finished photograph on site. All we would need to do is print. We can but dream.

Expose ’n Compose is a handy technique when you find yourself in the middle of changing conditions with a small camera and a lot of light and dark. It helped me produce a commended image a few years ago. Perhaps it’s even a metaphor for these dark days we find ourselves in. Lots of shadow and darkness but make sure to concentrate on the light.