Velocity can be measured using several methods. The simplest is to measure how much time it takes for a particle to travel a certain distance, using precise time-of-flight detectors. Another method looks at how much a particle ionises the matter that it passes through, as this is velocity-dependent and can be measured by tracking devices.

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Accelerators at CERN boost particles to high energies before they are made to collide inside detectors. The detectors gather clues about the particles – including their speed, mass and charge – from which physicists can work out a particle's identity. The process requires accelerators, powerful electromagnets, and layer upon layer of complex subdetectors.

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Set your camera mode to aperture priority (“A” on Nikon, “Av” on Canon) and work on creating that nice separation from the background. Focus on the ways of doing so that we discussed today.

A calorimeter measures the energy a particle loses as it passes through. It is usually designed to stop entirely or “absorb” most of the particles coming from a collision, forcing them to deposit all of their energy within the detector, thus measuring their full energy. Calorimeters have to perform two different tasks at the same time – stopping particles and measuring energy loss – so they usually consist of layers of different materials: a “passive” or “absorbing” high-density material – for example, lead – interleaved with an “active” medium such as plastic scintillators or liquid argon.

Tracking devices reveal the paths of electrically charged particles as they pass through and interact with suitable substances. Most tracking devices do not make particle tracks directly visible, but record tiny electrical signals that particles trigger as they move through the device. A computer program then reconstructs the recorded patterns of tracks.

The size of an image sensor, whether digital or film, affects depth of field in a similar way to a lens aperture. This is because depth of field is a product of both the lens aperture and focal length, plus the sensor size relative to that aperture and focal length.

Here you can see the dragonfly is in focus, but the grass behind is completely out of focus and blurry. I was close when I snapped this photo and was using my telephoto lens to allow me to get really focused in on my subject. This combination of closeness to the subject and use of a zoom lens enabled this level of background separation even though my aperture was at a mid-range setting.

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Collating all these clues from different parts of the detector, physicists build up a snapshot of what was in the detector at the moment of a collision. The next step is to scour the collisions for unusual particles, or for results that do not fit current theories.

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In order to see where depth of field begins to blur the background, look toward the upper right of the photo. There we begin to see the legs and feet of people walking past start to go out of focus. I would have preferred a smaller depth of field but this was a “let me test my manual setting really quick” shot of this boy running past me. I was so focused on getting settings nailed down that I didn’t even notice he’d fallen until I checked my screen and by then he was up and gone!

A small, tight, dark lens aperture lets less light into the camera, but because it is smaller, it focuses the light very sharply for a greater depth that extends in front of and behind the actual focus distance.

You’ve purchased a camera, you’re out there taking photos, and you’ve made your way to one of the premier resources for all things photography on the web, so I know you want to learn how to create eye-popping photos! With that in mind, here’s an assignment that will help you take your photo taking skills to the next level…

Depth of field (DOF), simply put, is the portion of your photo that is perfectly in focus. Due to the nature of camera components and the way they interact with light, every photo you take (with some random exceptions we won’t get into) will be impacted by your focal length, the distance to your subject (the object or person you are photographing) and your aperture. There are several mathematical calculations involved in determining exactly what depth of field you can expect, but as my goal is to make this subject a simple and easy to remember as possible, I’m going to forgo those explanations for today. If you have some free time and want to explore this in more depth, I’d recommend checking out an online depth of field calculator.

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Focal length: Greater focal length = shorter DOF. Distance to subject: Greater distance to subject = longer DOF.\ Aperture width: Wider aperture (smaller f number) = shorter DOF.

At CERN, we probe the fundamental structure of particles that make up everything around us. We do so using the world's largest and most complex scientific instruments.

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Not only is this an example of “the decisive moment,” it is an example of a larger depth of field. This is achieved by being a bit further from the subject in the photo and by having a smaller aperture opening.

Here is an example of blurred background using my prime lens. Utilizing a lower aperture and getting close to my subject helped keep the face, snow, and ice sharp, but blurred out the background details that may have distracted from the shot.

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Electromagnetic calorimeters measure the energy of electrons and photons as they interact with the electrically charged particles in matter. Hadronic calorimeters sample the energy of hadrons (particles containing quarks, such as protons and neutrons) as they interact with atomic nuclei. Calorimeters can stop most known particles except muons and neutrinos.

A large, bright lens aperture lets a lot of light into the camera and onto the image sensor, however such a big aperture also results in a very thin plane of focus, and a lot of foreground and/or background blur.

From these photos you can clearly see that with minimal effort and a basic understanding of how to control just a single component of your camera, you are able to completely change the texture and appearance of your photos.

Modern particle detectors consist of layers of subdetectors, each designed to look for particular properties, or specific types of particle. Tracking devices reveal the path of a particle; calorimeters stop, absorb and measure a particle’s energy; and particle-identification detectors use a range of techniques to pin down a particle's identity.

Particles produced in collisions normally travel in straight lines, but in the presence of a magnetic field their paths become curved. Electromagnets around particle detectors generate magnetic fields to exploit this effect. Physicists can calculate the momentum of a particle – a clue to its identity – from the curvature of its path: particles with high momentum travel in almost straight lines, whereas those with very low momentum move forward in tight spirals inside the detector.

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Today, though, we’re keeping things simple and to the point. To break this somewhat complex interplay between your camera and light down into simpler concepts, remember:

For good measure, here is another example with even greater depth of field. To capture this waterfall, I stood pretty close to the edge and shot alongside it while focusing midway across. Because I had a mid-range focal length and had my aperture opening pretty small, all the features in the photo are recognizable. You can clearly see the wall in the background and the rest of the waterfall in the foreground.

You’ll quickly get the hang of it and be sharing photos that have all your friends praising your photography skills on the social media platform of your choice!

One type of particle, the muon, interacts very little with matter – it can travel through metres of dense material before being stopped. Muons therefore pass easily through the inner layers of a detector, which is why muon chambers – tracking devices specialised in detecting muons – usually make up the outermost layer of a detector.

In addition to measuring a particle's momentum in tracking devices and its energy in calorimeters, physicists have further methods of narrowing down its identity. These methods all rely on measuring a particle's velocity, since this, in combination with the momentum measured in the tracking devices, helps to calculate a particle's mass and therefore its identity.

If a charged particle travels faster than light through a given medium, it emits Cherenkov radiation at an angle that depends on its velocity. Alternatively, when a particle crosses the boundary between two electrical insulators with different resistances to electric currents, it emits transition radiation, the energy of which depends on the particle's velocity.

Here is an example of how distance and focal length can impact your depth of field. The closer you are to your subject, the more likely you are to blur out the foreground and background of your photo. That probability increases as you increase your focal length by zooming in. I was less than two feet from Mr. Bug here (close enough for him to stare back at me) and had my lens extended all the way. Even though my aperture was set to a mid-range value of f6.3, the fore and backgrounds are pretty blurry, helping the eye focus on the subject in the center of the frame.