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Sport photography: noise reduction in post-processing

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Sports photography often requires very fast shutter speeds in order to freeze the action. In my experience, a minimum of 1/800 sec is required for basketball or soccer. My typical setting, which I save as a custom function in the camera is 1/1000 sec. Since lighting is often quite dim, particularly during indoor events or night games, fast shutter speeds require very high ISO settings, even with “fast” lenses (i.e. lenses that have large maximum aperture). As a result, the images become quite noisy, even when shot with state-of-the-art cameras, such as Canon EOS 5D Mark III or Canon EOS-1D X (in the Nikon world, there are counterparts such as Nikon D800 and Nikon D4S).

Noise becomes more noticeable when viewed at high magnification as random variations in brightness and colour between neighbouring pixels. These variations can be smoothed out in post-processing using fairly sophisticated algorithms implemented in various image-editing software. However, ultimately, this noise reduction causes loss of detail, which appears as lack of sharpness.

The good news is that in sports photography, relatively high levels of noise are considered acceptable. In fact, certain amount of noise adds character to the photo and conveys the sense of extreme effort exerted by the athletes.

Also, noise reduction is not nearly as destructive to the sharpness of the photo if the image is down-sampled (reduced in size) to be shown as a thumbnail on screen, for example. The counter-intuitive fact is that when the size (in pixels) of an image is reduced, the apparent sharpness is increased. This is because the small details that are lost due to noise reduction processing would not be visible anyway in the small image, so it appears both sharp and with low noise. The same is not true about the noise level, however. When the image size is reduced, the apparent noise is at best appears the same and often looks more pronounced than in the original, high-resolution photo.

Here are my typical strategy for noise reduction in Adobe Photoshop Lightroom, where I do most my post-processing. The Noise Reduction panel of the Develop module offers separate control of two main types of noise: Luminance and Color. Each of those has additional aspects, which can also be controlled separately (detail and contrast for Luminance and detail and smoothness for Color), but I almost never use them. I find the colour noise more unpleasant than the luminance noise, but it is also better controlled by the camera, so I rarely have to correct for it. I only work with Luminance slider for most of my photos.

  • If the noise level is relatively low, I find that Luminance settings between 0 and 10 (in some arbitrary units used by Lightroom – they are really just relative indicators of the amount of noise reduction applied) do not cause visible loss of sharpness.
  • If the noise is extreme, I set Luminance to around 30 and sometimes up to 50. Above that, the loss of detail is quite severe, and would be noticeable if the image is reduced in size.

More photos here: http://ow.ly/Ci0o7

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Image editing: an easy way of applying adjustments to a selected area

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One of the most basic, but most useful techniques that I use in Adobe Photoshop is applying an adjustment only to a part of the photo. There are many different ways of doing this, but the procedure described below bypasses a tedious selection of of the small details of the area that needs to be adjusted.

Let’s consider the photo of the young dancer above as an example. Suppose that we want to increase the exposure of the girl, but leave the background as is. Note that increasing the exposure here is just an example of an effect. Similar things can be done with saturation, contrast, blur or other effects. The point is to show how to apply the effect selectively. Here is the set-by-step procedure:

1. Open the file on Photoshop. The image will be place on the background layer of the Photoshop document (as shown in the Layers panel at the bottom right of the Photoshop window).

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3. In the Curves Properties window that appears, click in the middle of the curve and drag the handle that appears upward. This makes the entire image lighter, but at this point, consider only the dancer’s figure and mentally ignore the background – it will be excluded later. Also, you don’t have to be very precise with the degree of the adjustment either – it can be easily tweaked later (see step 7).

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4. Select the layer mask of the curves layer and press CTRL-I. This fills the layer mask of the Curves layer with black colour, hiding all adjustments.

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5. Select a soft round brush bush and with the layer mask selected paint with white colour, revealing the areas that are supposed to be affected by the Curves adjustment.

Couple of notes:

  • I use a pressure-sensitive Wacom Intuos Pro graphics tablet for these edits – it makes an enormous difference compared to using a mouse. In fact, I would not attempt this with a mouse, unless there would be no tablet available.
  • There is a very useful keyboard shortcut for changing size and hardness of the brush: With the brush tool active, press Shift-Option (or Alt)-Control and drag left-to-right to adjust size or drag top-to-bottow to adjust hardness. A red image of the brush will appear to serve as a visual guide for these adjustments.
  • There is no need to be very precise at this step. If you paint part of the background next to the girl, just ignore it – it will be taken care of at the next step. If you make an obvious huge mistake, paint the area black to hide the Curves adjustments there.

6. Now, the roughly painted-in selection can be refined in one easy step. There is no need to spend time selecting every individual hair around the dancer’s head, etc.

Instead, Double-click on the Curves adjustment layer anywhere to right of the layer mask. This opens a Layer Style menu.

At the very bottom, where it says “Underlying Layer”, press Alt (or Option) and click on the left (black) handle. This slits the handle in half; drag the right half to the right while observing the effect of the photo. Doing so makes the the Curves adjustment layer visible only in the areas where the underlying layer is brighter. Incidentally, if you Alt (Option)-click the right (fray) handle and drag one half of it to the left, you make the adjustment layer visible in the areas where the underlying layer is lighter. Once you’ve adjusted the slider position(s) to achieve the desired effect, click “Ok” in the Layer Style menu.

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7. If the adjustment is too strong, it can be tweaked again in theCurves Properties menu – you can open it by double-clicking the Curves adjustment layer just to the right of the visibility icon, which looks like an eye. Alternatively, you can adjust the opacity of the entire adjustment layer to mute its effect.

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8. This is it! Go to File > Save as… and save the file in a format that you need.

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On imperfect conditions

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“It is, after all, the dab of grit that seeps into an oyster’s shell that makes the pearl, not pearl-making seminars with other oysters.”

– Stephen King, “On Writing.”

I wrote in this earlier post on waterproof gear that bad weather often makes good photos. In fact, incorporating weather (read:bad weather, form a conventional viewpoint) in a photo is almost a requirement in some genres of modern photography. Indeed, Ansel Adams is arguably the most famous photographer ever mostly because he was ahead of his time by using weather elements in his landscapes. Nowadays, every landscape photographer does it.

However, it is not just imperfect weather conditions that promote creativity. Other challenges are also very effective in developing a photographer’s skill. For example, shooting in low light is challenging, but the results are usually worth the effort.

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Likewise, shooting sports action is difficult because of the fast, unpredictable movement of the athletes, lack of control over light, etc. For a while, I was using a Canon EOS 5D Mark II as my main camera and felt that the low framing rate and slow autofocus were really limiting the success rate of my shots. After upgrading to the unbelievably fast Canon EOS-1D X , I can definitely say that my experience with the 5d Mark II was very valuable, as it taught me to determine the characteristic moments of the action, whether it is basketball, soccer, rugby or swimming. If I didn’t have the sense of those decisive, characteristic moments for each sport, it would have been tempting to just let the 1Dx rip at 12 frames per second from the beginning of each play until the end. This would have left me with tens of thousands of poor images, among which it would have been impossible to find a single good one, that would tell the story of the game.

More photos here: http://ow.ly/Ci0o7


So in order to improve at photography, I try to:

  • Shoot challenging subjects;
  • Shoot in difficult light and poor weather;
  • Practice with whatever gear we have to find out the limits of a particular piece of equipment – it makes the new gear, when it becomes available, much more effective.

 

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Using crop tool to improve composition

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Often, it is not possible to perfectly compose the photo at the moment of shooting. This is particularly true for action photography, but it is quite common in most real-life situations when we don’t have total control of the model, the background and/or have limited time to take the shot.

Post-processing can dramatically improve a photo, and one adjustment that has the highest impact is cropping. Cropping affects composition, which is the most fundamental element of a picture. It allows us to emphasize the subject and remove non-essential or distracting parts. In Adobe Lightroom, the crop tool located at the very top of tool panel in the “Develop” module. This is not a coincidence. The tools are laid out in the order of the recommended (read: common) post-processing workflow, where the most important, high-impact adjustments are made first.

Recently, I have been taking increasingly more pictures with my iPhone. Before sharing them online, I often make some rough adjustments using the editing mode of the built-in Photos app. Cropping is usually one of them. Here is what I typically do to improve composition:

  1. Straighten horizon.
  2. Cut off unnecessary/distracting elements that do not contribute to the story I am trying to tell in the picture. When in doubt – crop tighter.
  3. Try to use “the rule of thirds” (position the mail element of the picture at the intersection of imaginary vertical and horizontal lines that divide the width and the height of the picture into thirds). for example, in the image above, the face of the fisherman is positioned 1/3 of the frame height from the top of the frame and 1/3 of the frame width from the right side.
  4. Crop the image so that any diagonal lines intersect a corner of the photo – it helps leading the viewer’s eyes into the frame. Again, in the image above, the strings lead from the bottom left corner of the frame towards the middle. Also, the diagonal planks on the hull of the boat lead from the bottom right corner.

Note: It is a good idea to keep these points in mind during the shoot itself to avoid excessive cropping in post-processing, which reduces the number of pixels (i.e. resolution) in the final photo.

Recently, I was taking headshots of the faculty members of my daughter’s dance school for their website, and looked into various ways of cropping the portraits. One rule of thumb for cropping a headshot is that cutting off the top of the model’s head makes the portrait more appealing. It may seem counter-intuitive, but this kind of close crop emphasizes the person’s eyes and make her/him appear engaged with the viewer.

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At the restaurant: dealing with low-light conditions

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Restaurant is a common setting for a group portrait, because dining out often commemorates a special occasion, as in the photo above – last Saturday we went out to celebrate my wife’s birthday. Using flash is not a good idea for several obvious and not-so-obvious reasons. In addition to disturbing other customers, a flash would completely change the character of the lighting, so capturing the ambiance would be out of the question.

Restaurants are typically dimly lit, so low light performance of the camera is very important. This characteristic cannot be narrowed down to one particular specification. It depends on the lens, the sensor and the firmware. Cell phone cameras cannot compete with DSLRs in this regard, so if you must use a cell phone, the first thing to adjust is your expectations.

If you choose to bring a DSLR, a fast lens (f2.8 or lower) is a must. Also, the lens-camera combination should ideally be relatively compact. In the Canon world, a Canon EF 35mm f/1.4L USM is an excellent lens for this situation. Sigma also makes a good quality 35mm f1.4 lens (Sigma 340101 35mm F1.4 DG HSM), which is quite a bit less expensive. (By the way, these are just recommendations based on my experience, and although the links are affiliated by Amazon, they are not sponsored in any other way). In fact, compactness would be a very good reason to choose a cell phone over a pro camera – after all, it is a dinner first and a photo opportunity second. Having said this, I shot this photo with a Canon EOS-1D X, which is anything but compact. My family is probably getting used to me lugging a huge camera. I’d like to think that the photos are worth it. (Still, I am waiting impatiently for my new iPhone 6 plus, with its image-stabilized camera…)

Here is a roundup of the best cameras for low-light conditions compiled by Adorama (as of Summer 2014). A colleague has recently used their top choice, the Sony Alpha a7S, to photograph a fluorescent helium jet seeded with acetone in near darkness in our lab at UVic. But that hardly qualifies as a common photography situation, so it’s a subject for another story.

As a more general resource for handling low-light situations, check out this book: Chasing the Light: Improving Your Photography with Available Light.

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Window light

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Window light is ideal for indoor portrait photography. In fact, some light modifiers (e.g. umbrellas or soft boxes) used in studio lighting setups are designed to replicate this natural lighting condition. There are several good reasons for this.

First, a window is a very large light source, compared to the subject, which results in a diffused, flattering light with soft shadows (smooth transitions between the lighted and shaded areas). A general rule that applies here is this: large light source (e.g. cloudy sky) = soft shadows; small light source (e.g. uncovered light bulb) = harsh shadows.

Second, the colour temperature of the daylight matches that of a daylight-balanced (read: standard) flash, which makes it very easy to use a fill-in flash without having to worry about correcting the skin tones in post-processing. A caveat here is that the shoot is happening close to the middle of the day, not during the “golden hours” around sunrise and sunset that are so desirable for outdoor portraits. So, here is a tip: schedule an indoor photo shoot during the day, if there is an access to a large window.

Third, there is something “right” about the height of the light source represented by a typical window – it is neither too high nor too low to cause unnatural shadow patterns on the subject’s face.

Because of these nice features of window light, I always try to take advantage of it when my daughter is getting ready to go out and is looking out of the window in our hallway. These moments are fleeting, so here is another tip: experiment with camera setting beforehand and save them as a custom preset if your camera allows it. (Here is how to find custom functions in a Canon EOS camera.)

In the photo above, my daughter is going to Raffi‘s concert, and to a dance class in the image below.

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Young athletes

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I was taking photos of Vikes children’s summer camps couple of weeks ago and noticed how wide is the range of athletic abilities of the kids of the same age. Boys and girls, who are about ten years old, are particularly different.

At the Boulder rock climbing gym at Stelly’s Crossroad, most of the boys noticeably struggled to climb much higher than about twice their own height. I must say, I clearly remember that I was the same at that age – any sort of climbing was not my strong suit. (Come to think of it, I might still be the same now…) However, some girls from the same age group literally walked up the climbing wall, all the way to the 50-foot-high ceiling. Clearly, girls have an advantage in terms of power-to-mass ratio!

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Interestingly, things were just the opposite in the soccer camp. With very few exceptions, little girls were quite unbalanced when striking the ball – from the kendo background, I could clearly see that their weight shifted to the back foot as they ran up to the ball and also during the defending drills (for the older girls). On the other hand, most of the boys could kick through the ball quite confidently, keeping their balance throughout the motion.

Correction (few days after): now after looking at the photos, I can say I was wrong about the soccer: boys and girls look about equal – most are quite clumsy. Image below is an exception – this little dude was amazing!

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