tutorial

Capturing Images of Rain – 33

Jackie Ranken explains the best way to capture images of rain

In the ’60s a famous New Zealand photojournalist named Brian Brake experimented with the idea of photographing rain. He was a member of the legendary photographic agency Magnum, run by photographers for photographers. Magnum’s members had what its co-founder Henri Cartier-Bresson described as “a curiosity about what is going on in the world, a respect for what is going on and a desire to transcribe it visually”.

Many of us have this desire to transcribe the world, to make images that communicate. Many of the best photographs in fact start with a simple idea or line of thought. Brake was shooting a photo essay entitled ˜Monsoon’ in India. He wanted to make photographs that communicated ˜wet’ and ˜people’, or in this case ˜very wet people’. During this project, Brake created a famous image of a woman’s face covered in rain. By using a reasonably slow shutter speed of around 1/30 of a second, he captured the loaded droplets on her face with the rain visible as small-lines against a dark background.

By practising your skills in a controlled environment before heading out on your own assignment, you’ll be surprised at what you can learn. Photography is about doing, so pick up your camera and do your ˜photographic scales’. It’s fun, especially when you solve all the problems and come away with some nice images. By analysing the results you can then apply this knowledge to many other situations. Try the following:

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Doogan Tours Lightroom and Italy.

Official Photoshop Wizard John Doogan has announced a two day hands-on workshop in Auckland this June, where the Adobe Certified Expert will turn Lightroom inside-out.

Lightroom, which is fast becoming standard-issue kit, will be explained from the ground up, with Doogan covering digital asset management, metadata, keywords, the develop module, importing and exporting images, plug-ins and workflow (whatever the heck they all are).

Held at Evoke Studio in Papakura on June 5 and 6 at the bargain basement price of $458 , there’s very limited places, so email sued@designertech.co.nz for a spot.

Doogan will also be hosting on a special Mediterranean education later in the year, leading an 11 day photo tour through an Italian village during harvest season. Participants will stay on a working vineyard, where they can combine their love of learning about good photography with great Italian grub.

Held between September 27 and October 7, 2010 more information is available at www.italyphototour.co.nz

High Megapixels Magic Trick

Sarcastically saying, this magic trick saves you money for an unnecessary camera upgrade so you can invest more in lenses instead of new camera bodies.

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How to Photograph the Moon Part II

This video demonstrates you how to take an excellent close up photograph of the Earth’s Moon without a name – also demonstrates you how to develop the RAW (or NEF) files in Adobe Photoshop Lightroom (We use the original LR in this tutorial but similar results in LR 2) and Adobe Photoshop CS3 (similar results in CS4)

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Jackie Ranken: Exposure, Aperture, Shutter Speed and ISO

In this article I really wanted to take you somewhere new and discuss the wonderful  features available in today’s dSLR cameras. But as the words started to flow I realised that I would have to go back to the basics to lay the path for new students taking up photography and wanting to understand how their cameras work. I suggest as you read the article you refer to your camera manual — and don’t be lazy; do the practical exercises and learn.

There are two ways light enters the camera: the aperture and the shutter. The aperture is the hole, and the shutter is the blind that sits between this hole and the sensor in the camera.

The aperture number has an ˜f’ number in front of it. Small aperture numbers have the larger holes (f2.8, for example) and big aperture numbers have a small hole (f22). The shutter is a kind of blind that can open slowly (in fact it can stay open for hours on a setting called Bulb) or it can open and close so fast it can’t be seen with the naked eye. When reading the shutter speed, 1/60 (for example) is one-sixtieth of one second.

Both the aperture and the shutter work together to allow varying amounts of light through to create an exposure. If one is letting through most of the light, the other needs to balance this out by letting through less light.

Images will look different depending on which mechanism we choose to let the largest amount of light through. If most of the light is coming through the shutter, then the visual effects will be weighted towards the recording of motion or time. In effect, slow shutter speeds are a result of small aperture holes and/or low light, and fast shutter speeds are a result of open apertures, bright light or high ISOs.

ISO refers to the sensitivity of your camera’s sensor to light. Setting your camera to the lowest ISO will allow you to use slower shutter speeds than when ISO is set to a high number. In the past, image quality diminished noticeably once you set your ISO beyond 400. The images were grainy and had less detail, what we would call ˜noisy’, but the latest dSLRs have greatly improved image quality at higher ISOs. They have also extended the range of ISO to 6400 and beyond. This is great for handheld photography and when the light is dim, or for when you use a longer focal length lens and need to keep your shutter speed faster than the focal length of the lens to minimise camera shake.

Experiment with your ISO. Take consecutive shots of the same scene with your ISO set first at 100, and then go up to the limit of your camera. Do this in different lighting conditions and compare the resulting images on your computer, then you will know how your camera’s sensor looks at high ISO compared with low ISO.

To have control of your shutter speed and aperture you will need to select one of the four shooting modes found in all dSLR cameras. These are: M for Manual control, Av for aperture priority, Tv or S for shutter speed priority and P for program.

It’s my experience that the best way to learn about aperture and shutter speed controls is by deliberately taking time out to learn and play.

Tv is where you select the shutter speed and the camera selects the aperture. P mode is most like the auto mode, the differences being that the flash won’t pop up unless you make it, and you will have access to the exposure compensation dial.

My favourite shooting modes are M mode or Aperture priority mode. M mode signifies full manual control, where the photographer has to choose both the aperture and the correct shutter speed for the subject. It’s not that hard but you do need to be constantly watching the light and making adjustments. The most consistent exposure reading is made by measuring something in the scene that you know is close to grey in tone. You may notice your light meter jumping all over the place as you scan the scene. This is because it is responding to the different amount of light being reflected off objects. But if you use matrix metering, where the camera averages out all the light entering the camera, your exposure should be close. Check your live histogram in Live View (if your camera has it) or in your LCD screen after the exposure. Once you have confirmed your exposure is right for the main subject in the image then you can keep shooting with these settings until the light changes. (Look and compare the histograms and images supplied.)

In Av mode, as you change the aperture the camera will change the shutter speed for you. Exposure is adjusted to make an image darker by moving the exposure compensation button to the negative (—ve ), and brighter by moving it towards the positive (+ve).

In both methods you will need to have activated the camera’s light meter by half pressing the shutter release button. You will notice an exposure scale with numbers from up to  -3, -2, -1, 0 +1, +2, +3 . The ˜0’ represents grey or mid-tone; -3 is three stops darker and +3 is three stops lighter. (Please check your camera manual for more information and find how to lock your exposure in Av mode.)

Practice: Understanding Exposure

Mount your camera onto a tripod — this helps you to slow down and concentrate. Then take consecutive images of the same subject using different combinations of aperture and shutter speed. Explore photographing different subjects from light to dark. Use your exposure scale and histogram to obtain the correct exposure for the subject. Dark subjects should look dark and light subjects should look light, and the pointer in the exposure scale will move from —ve when you photograph something dark to +ive when you photograph something bright.

The histogram will show the dark tones on the left-hand side of the scale and light tones on the right-hand side of the scale with mid-tones in the middle. The white or brightness histogram is a combination of the red, green and blue channels; combined, they make white. Find your histogram in your camera, notice how different scenes have different amounts of tones from dark to light.  Tones that hit the edge on the left are black, and tones that hit the right-hand side are  white.

Download and compare the images on your computer. Most image browsers will display the metadata about how each file was made. Make comparisons and value judgements on what has worked and what hasn’t worked. In this way and with practice you will begin to program your mind to be able to use the camera instinctively.

Aperture controls depth of field or depth of focus:

The smaller the aperture hole, the less light. The small hole is represented by a big ˜f’ number. The bigger the ˜f’ number, the bigger the depth of field or how sharp an image is in front of and behind the point you are sharply focusing on. The focus comes forward 1/3 and back 2/3rds from this point. Visa versa applies for a small ˜f’ number. It represents a big hole and a narrow depth of focus.

Practice: To learn about aperture.

You will need to have an object quite close to the camera, a subject (to focus on) one-third of the way into the scene and something far away in the distance. The reason for this is because the further you focus your lens away from the camera the further the depth of field will be. So if you don’t have something close to the lens to compare sharpness with, you won’t be able to see much variation at all between f5.6 and f16 and will wonder, what it is all about.

Take at least three shots. One with the aperture wide open (biggest ˜f’ number), one at f8 (because f8 represents the ˜sweet spot’ where the clarity of the lens is at it’s best), and then close the lens down to the smallest hole, f22 (remember: small hole, big number). The idea is to keep your exposure the same throughout. As you change the aperture to consecutive smaller holes the shutter must be similarly changed to longer times. Download and compare your images.

Shutter speed

The idea: To learn about the effects of different shutter speeds

I suggest photographing something that is constantly moving; do it in low light so your shutter speed is able to go slow. You will need a tripod and an external shutter release mechanism or self-timer to minimise camera shake when your finger pushes the shutter button. Fill the frame so you can see the movement. Make sure your Auto ISO is turned off otherwise the camera’s ISO will immediately increase in low light. And remember turn off your lens image stabilisation when your camera is mounted on a tripod.  Again, the idea is to have your exposure remain the same throughout.

As you change your shutter speed faster or slower to record movement at different speeds, you must move your aperture so the light is still balanced. Remember that if you want to achieve faster shutter speeds, raise your ISO to a higher number; if you want to achieve slower shutter speeds, turn off the lights or put a circular polariser on your lens.


Related Tips

  • You need to have control. It is this, and the decisions you make with the 20cm of grey matter behind the camera, that make the difference.
  • When you are hand holding your camera a balancing act is happening between, lens, aperture, shutter speed and ISO. Depending on which lens you have on, you will need to look at your subject and judge how much you want to stay sharp in (1/3), front of and (2/3) behind your subject. Keeping in mind that wider angle lenses (18mm-35mm) will have a bigger depth of sharpness compared to longer focal length lenses (80mm-200mm). Select an aperture that will give you your desired depth of focus, remembering that your shutter speed needs to stay faster than the focal length of the lens, so in order to achieve both outcomes you may have to raise your ISO.
  • Using a narrow depth of field is one way of making your eye go directly to the subject, and goes hand to hand with getting a faster shutter speed.
  • Using a latest release Canon dSLR with ˜Live View and image simulation’ selected is a great way to learn the basics. You will see the image go lighter and darker as you change your settings. Press the info button or display button to even bring up a live histogram on your LCD screen.
  • JPEGs are ˜lossy’ files. This means that each time you change something then re-save, the file becomes recompressed and loses a little bit of information — every single time. It’s best to rename and/or save the file as TIFF files or PSDs (Photoshop) if you are going to make constant changes.
  • If you have a large group of people to photograph, with the intent of keeping them all as sharp as possible, you would have your focusing point select a person one-third of the way into the group, not the front row. Knowing exactly where you are focusing is another level of control you require. Read your camera manual to find out how to change from the various modes: auto select, face recognition, Live View manual focus and so on.

How to Photograph the Moon Part I

This video demonstrates you how to take an excellent close up photograph of the Earth’s Moon without a name – also demonstrates you how to develop the RAW (or NEF) files in Adobe Photoshop Lightroom (We use the original LR in this tutorial but similar results in LR 2) and Adobe Photoshop CS3 (similar results in CS4)

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Tutorial: Raw Conversion with DxO Optics Pro

RAW or JPEG? That is the question. Some pros couldn’t be bothered setting their camera to RAW; some amateurs wouldn’t dream of shooting anything but. We have looked at the pros and cons many times over the last few years and I am not going to go into any detail here.

In short, RAW files aren’t processed by the camera; they contain the raw data as seen by the sensor. Think of RAW files as undeveloped film waiting for you to decide how to process it. Think of JPEGs from your camera as prints you’ve got back from the corner store — it’s all been done for you.

Apart from Lightroom and ACR, there’s a host of other converters: Capture One, Bibble, DxO Optics, ACDSee Pro, to name the best-known ones. And, of course, there are the ones supplied by the camera manufacturers. It is often claimed that those are the best ones to use, which makes senses because the camera manufacturers should know best what goes into their RAW files. And that brings us to the next question: what converter should you use?

Trying to find the best program is like hitting a moving target. Every new generation claims to do a better job and comes with more bells and whistles. Any critical comparison gets you into pixel-peeking territory before any meaningful differences might show up. In other words, in real life you won’t find a true winner.

Why, then, are we going to look at yet another RAW converter? Because DxO Optics has got some unique tools to correct lens problems. Incidentally, DxO works with JPEG files as well, but they must be straight out of the camera.

DxO Optics Pro

DxO Labs is a French company, well known for its DxO Analyser, a professional optical test system designed for use by camera and lens makers. The company developed mathematical tools for measuring the various optical characteristics of lenses and sensors. It was only a logical step to use this information to correct lens flaws. This is what DxO Labs has done with Optics Pro.

Version 6 for Windows, which came out in November last year, is the latest incarnation of the program (Mac users had to wait a bit longer but it should be out by the time you read this). The program has improved over the last few years, especially the interface, which was quite clunky in the first few generations.

You have the choice between two versions: Standard (US$169 — about NZ$242) or Elite, at US$299 (NZ$428). They both use the same technology with the Standard edition covering smaller cameras up to APS-sized dSLRs, and the Elite version also including full-frame sensor models.

Every camera-lens combination has a dedicated module, which you need to download. For example, two cameras and six lenses require 12 modules. But you don’t need to worry about that. Just make sure the edition you bought covers your camera and, if the program comes across a new lens, it is going to ask you to download the corresponding module. Currently the Elite edition covers more than 1600 camera/lens combinations and new ones are being added all the time. If your specific combination is not included, the program won’t be able to apply any automatic corrections, but you will still be able to make manual corrections.

In practice you simply present the program with a folder full of different shots and it will automatically get the necessary information from the metadata and choose the right module. There are regular updates to cover the latest camera and lens models.

What it does

The pixel count of our cameras keeps going up and has now reached the late teens and early twenties. This high pixel density really challenges our lenses. Only the very best lenses will show you what your latest camera is capable of.

Ideally we should only work with prime lenses — and even they have their fair share or vignetting and chromatic aberrations. But we all love the convenience of zoom lenses. Zooms, and in particular the wide-angle ones, are a challenge to designers. They need to compromise between sharpness, aberrations, distortions, vignetting, size, weight and — yes — price. What you finally get is a lens with barrel distortion on the wide end, pincushion distortion at the long end, vignetting, chromatic aberrations and softness towards the edges. All of these defects change with the zoom setting, the aperture and the focal distance.

DxO Optics Pro promises to correct all of these lens faults for you — automatically! No, it can’t turn a bad lens into a good one, but it can make a mediocre lens a lot better, and a good lens can be raised up to being terrific.

But there is more. It is also an excellent RAW converter that has an uncanny ability to extract the best conversion from nearly every RAW file you throw at it. One of the coolest features is the DxO ˜Lighting Engine’, which does a superb job in performing local exposure and dynamic range corrections to bring out the most detail in dark shadow and overexposed highlight areas. Version 6 has the latest noise reduction feature, which is a hardware-based correction. This means that noise reduction is tailored to the specific camera used and that the correction will only be applied to images from cameras that have been calibrated by the program. DxO Labs claims a two-stop improvement in the noise level, while retaining maximum detail.

The DxO Optics Workflow

The program does not work as a plug-in, but it allows you to import and export images to and from Lightroom. Working from Bridge, you can also pull one or a group of images into DxO with the mouse.

Image 1 shows you the opening Window of DxO:

DxO works on projects. Managing a project involves four main steps, each one with its own dedicated tab. The first three are the most important ones: Select, Customise and Process

You start by selecting images in the left-hand ˜Browse’ pane. The images from a specific folder come up as thumbnails in the large main window.

Next you select the shots you want to work on and drag them into the ˜Project’ pane at the bottom.

It is important to remember that DxO only works with files straight out of your camera. You can use Lightroom or Bridge to copy the images from your camera cards, you can even add a metadata template, but you cannot translate them into DNGs. DxO simply doesn’t see files that have been changed in any way.

Next, click on the ˜Customise’ tab. Here you can find all the controls to customise your settings for the Raw conversion.

Beginners will feel overwhelmed by the number of sliders and other options. Coming from Lightroom or ACR, however, you will find all your familiar tools. The layout is different but you will find your way around quite quickly without having to page through the user manual.

There are the usual viewing options for single screen, split screen for comparing the before and after image, and the various zoom settings.

Before getting down to business with all the controls on the right-hand side, have a look at the drop-down menu on the top, labelled ˜Presets’. Here you can find some handy shortcuts, such as ˜DxO Defaults’, ˜Lens only’, and so on. Eventually you will want to store your own customised presets here.

Now let’s have a brief look at the individual controls. These are all grouped under four main headings: Light, Colour, Geometry and Detail. Each one has a number of subheadings that can be expanded and collapsed by clicking on the little triangles. The next image shows you the controls for ˜Light’.

The drop-down menu for the ˜Exposure compensation’ sub-menu gives you four auto and one manual adjustment options. Typically you will find that most controls have an ˜auto’ setting, which in general does an excellent job and keeps things simple for you. If you are not happy with the results or if you want to squeeze the last detail out of your RAW files, switch to the manual controls.

It is the ˜Geometry’ group which makes this program unique.

The first subheading caters for lens distortions. You will want to leave that in automatic mode. In the unlikely event that your camera/lens combination is not covered, you can opt for manual correction. The program gives you the choice of barrel, pincushion or fisheye distortion correction with a slider. Yes, you can even ˜de-fish’ your fisheye shots and get some perfect extreme wide-angle shots that no existing lens would allow you to take!

But the real beauty is the auto mode, where the program applies the precise correction, depending on your lens and the zoom setting. Many if not most zoom lenses have a complex, high-order distortion, which is not a simple barrel or pincushion distortion. Lines parallel to the edges are not simply curved, but go back and forth and back again. This is not something you can repair in Photoshop’s Lens Correction filter.

Volume Anamorphosis, the second item on the Geometry tab, corrects another optical phenomenon that distorts 3D objects close to the camera, especially with wide-angle lenses. Think of columns near the edge in an architectural image, or people’s heads in a group shots taken at short distance.

The third subheading allows you to make keystone corrections. This is not a lens problem but shows up as non-vertical lines if you point your camera up or down. Everybody has seen images of buildings that seem to be leaning backwards. Images 5 and 6 show you an example before and after correction. Note the non-vertical lines of the organ pipes and the columns caused by having to point the camera upwards in order to get everything into the picture. But also note the curvature, especially of the right-hand column. This is caused by the barrel distortion of the zoom lens at its widest 24mm setting.

Auckland Town Hall organ before lens and perspective corrections (Canon 24-105mm f/4 L IS USM @ 24 mm f/5.6, EOS 5D Mark II)

Auckland Town Hall organ after lens and perspective corrections

The last development heading is labelled ˜Detail’ and caters for lens softness, sharpening, noise reduction and chromatic aberration.

After setting up all the parameters you go to the ˜Process’ tab and choose from a number of output option. The program lets you select between TIFF (8- or 16-bit), JPEG and DNG.

How will DxO Optics Pro fit into your workflow? If you are a perfectionist who spends hours at the computer after every shoot, give this program a go. Leave it on full automatic; you will be surprised at the results. You might then want to fine-tune your top two or three shots by hand.

By Hans Weichselbaum