This article is about ways to control the exposure of the foreground and background in a photograph.

When a photographer takes a photo with a lens set to a very wide aperture, then the depth of focus is narrow from front to back.

Using a narrow aperture would make much more of the scene from front to back in focus. But here we are talking about separating the foreground from the background.

With a wide aperture set on the lens, the background is rendered blurred and out of focus while the main subject is sharp and in focus.

Lenses with wide maximum apertures tend to be expensive because they require bigger glass in the elements that make up the lens.

An aperture of f1.8 in a short focal length lens is pretty standard. An aperture of f1.4 is less common, and f1.2 is pretty unusual and usually very expensive.

So a wide maximum aperture can blur the background, but it cannot make the background darker or lighter than the main subject.

Flash

Flash can make the background darker or lighter than the main subject by illuminating the main subject and setting the exposure of the camera to render the entire scene darker than it would appear to the human eye.

The neat thing about flash is that it overrides the shutter speed you set – at least for the area that the flash covers.

So if you use a tiny flash that only illuminates the subject and isn’t enough to illuminate the whole scene, then the flash exposure speed of around 1/2000th of a second will expose the subject, and the shutter speed – which might be 1/250th of a second will expose the background.

So then, if you manually set the shutter to something faster than 1/250th of a second then less ambient light will get in and the background will be darker than the subject.

But if you don’t use flash then you can use Lightroom Classic because it is pretty good at identifying the subject.

You can mask different part of the scene and then you can alter exposure of the subject and the background independently .

That’s what I did here in the photo above.

Here is the same shot balanced as the camera saw it (and as the human eye would see it).

As you can see, the background is blurred because I used an aperture of f2.8 which is almost the widest aperture possible on the Fuji X100F that I used.

The Fuji is a fixed lens camera with a maximum aperture of f2.0, and if I had shot at that aperture than the people in the background would be slightly more blurred.

And if I had wanted, I could have blurred the background more in Lightroom in the background masked layer.

Using Lightroom Classic

The masking tool in Lightroom Classic is not perfect, but it is very good at picking out a subject, as you can see here in the screenshot taken from my Lightroom Classic.

To activate the masking feature, click on the dotted circle (the second icon from the right below the word Histogram). Choose ‘subject’ from the three options, and it will highlight in red what it thinks the subject is.

Assuming you like what it chose, put your cursor next to the icon (named Mask 1 here) and you will see an option to create a new mask layer that covers the invert of the subject.

Do that and you have now have two masks – one of the subject and one of the background and you can work with the subject and the background independently.

That means you can sharpen, lighten, darken, blur, and do any of the actions that in the list in the sidebar by using the sliders.

As you can see in both the ‘normal’ shot and the Lightroom masked version, the background is blurred. it is blurred because I used an aperture of f2.8 which is almost the widest aperture possible on the Fuji X100F that I used.

The Fuji is a fixed lens camera with a maximum aperture of f2.0, and if I had shot at that aperture than the people in the background would be slightly more blurred.

And if I had wanted, I could have blurred the background more in Lightroom in the background masked layer.

And that’s it. I learned this technique recently from a YouTube presentation. I can’t remember which one but if I do then I will add a link here.

Description

A man with unkempt grey hair sits on the pavement by the exit to Oxford Circus underground station. He sits bent over, wrapped in a blue blanket, with his legs straight out. He wears Nike Air Max 95 Retro trainers. A shallow tray is on the ground by his left foot.

Behind him is a black wheelchair and a Council rubbish bin. The wheelchair stands partly on strewn cardboard, wet in places.

On the cardboard is an empty tray, a paper carrier bag with string handles, a plastic bottle, a piece of thick brown material, and a piece of flimsy red material.

A tall man wearing a brown and black padded jacket is walking along the pavement and seems to look towards the man on the ground. He is hand in hand with a woman wearing a pale blue coat who looks down at the ground in front of her.

Two women are walking while involved in conversation. One has her hand and arm up expressively.

Further away, a woman is walking with a child and pushing a small pushchair with red cover. A man in a bright yellow shell jacket is three-quarters turned back, perhaps in conversation with the woman behind him.

There are other people in the scene.

Supplication is the act of humbly, earnestly, or desperately asking a deity or someone in a position of power for a favour, mercy, or help. It is an emotional plea rooted in deep dependence and respect.

Look just below the phone at the extreme bottom left of this photo, and the man with his hands raised.

Look at the enlarged a crop below to show the detail.

The explanation I heard about Krishna consciousness (see this post) suggests that it is not a personal request but an opportunity to be a better servant of the plan of the divine.

Photo taken from the balcony of the national Gallery in London, looking out on Krishna Chariot during Krishna Consciousness Festival, with Nelson’s Column and Big Ben in the background and an airliner flying past.

This is one of three chariots in Trafalgar Square brought in for a Krishna festival. It was explained to me that when the chariots are there, there is an opportunity to benefit from being in the presence of light from the divine.

So it was good not to miss it.

When I arrived, the chariots had not yet arrived. There were people there, but not in the numbers that gathered over the next hour or so.

That quieter time gave me an opportunity to relax and find people to talk to.

I read that the festival was coming and my calendar notes say ‘Hare Krishna Festival’.

I had it in my mind that the people there would be ‘Hare Krishna’ – not exactly borderline, but in my mind, not mainstream. But the people who came were whole families of, from their dress, straight up Hindus.

That was a surprise.

The tone, the mood, the underlying feeling of the gathering at Trafalgar Square was very peaceful and accommodating.

And I met several people who helped me piece together what the tradition understands of what life is and what its trajectory is.

I spoke to this man, who is a disciple of the man who originated the International Society for Krishna Consciousness (ISKCON).

ISKCON is not peripheral to Hinduism and has roots that go back thousands of years in Vedic tradition.

Hare Krishna, Hare Krishna, Krishna Krishna, Hare Hare
Hare Rama, Hare Rama, Rama Rama, Hare Hare

To the all-attractive one, the source of all pleasure, engage me in your service.

It is a petition to the Divine, a prayer for spiritual awakening:

I spoke with a man who was born in India but who lives in the UK and is a doctor at one of the London hospitals.

He told me about the obligation to help others to relieve themselves from the endless reincarnation that attachment brings, because this world is suffering and impermanent. That is its nature.

I asked him why a person would want to do that, and to what end, and why it was set up like that.

That is where we got to.

I plan to visit the Centre in Holborn to continue the conversation, not least because it is enjoyable to be in the company of serious people. Certainly the man I spoke to was serious, and I enjoyed his company.

Fuji X100F

Again I took my Fuji X100F with me, and it coped well enough with the contrasty light. I say ‘well enough’ because contrasty light is just not as pleasant as softly diffuse light because of the harsh shadows and bright highlights.

The camera did less well in the tent, and I think it was the green tent wall that threw off the auto white balance and I had to adjust it in post processing. A grey card would have helped.