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DSLR – Getting blur free images!

07 Jun

Getting Started

Now that we have the basic DSLR functions and gear out-of-the-way, let’s continue exploring how to get blur free images. I say “blur free” more often than “sharp” since it is possible that a sharp image is not what is desired in certain cases. Although, there are “blur” effects as well, but, we will not get into that for now.

This is how I turn around in mid air!

Blur free image

Keep in mind that we are talking only about the creative modes on a DSLR, i.e., the PASM modes. In the PAS modes, you help the camera arrive at a better decision for taking an image of a given scene. In the M mode, you tell the camera what to do rather than help it to reach a decision.

As already indicated in previous posts, always watch the shutter speed. The other points to watch out for are how you actually press the shutter, the focus point and the overall exposure of the scene. Let us consider all of these in some more detail.

Shutter Speed

Shutter speed is the main reason, besides focus, that results in blurred images in my experience. In some cases, it might seem the other way round. Either way, we will look at both. A thumb rule to keep in mind is that the shutter speed should always be high enough to avoid camera shake and subject movement. The camera shake is generally minimised or eliminated by following the 1/FL rule.

This means that your shutter speed should always be equal to or higher than the focal length in use for the shot. For example, if you are using a 55-300mm lens and shooting at 300mm, then, the shutter speed should be at least 300 x Crop Factor. For Nikon cameras, this would be 1/450 and for Canon it would be 1/480 since the crop factor for the Nikon sensors is 1.5 and for Canon it is 1.6. The camera will not have either of these speeds and therefore the next stop is 1/500th of a second.

PIF - Pigeon in Flight

Bird in flight

Most lenses (or cameras) today have some kind of image stabilisation built-in. Using this mode on the lens will allow you to use somewhat slower than the 1/FL speeds and maintain a blur free image. In my case, I often shoot at 1/320 or 1/400 at 300mm. Sometimes, if I provide some more stability for the camera (leaning against a wall, monopod etc), then, I can slow the shutter speed even further. Of course, this implies that the subject is not moving faster than the shutter speed in use.

A typical case for using 300mm would be birds in flight or motion. These cannot be frozen under 1/500th of a second. Actually, you would generally start seeing this motion being frozen at around 1/1600th of a second or faster. The same applies when using shorter focal lengths like in the 18-55mm lens. Although you can shoot at 1/100th of a second at 55mm, you would now have to look more closely at the subject movement. This slow shutter speed might not be enough to freeze human subjects in candid shots.

Normally, you would step up to a shutter speed of 1/125th of a second or faster. Pets and children would require a similar or somewhat higher speed since they keep moving around a lot more. Birds and Wildlife also follow a similar pattern. The smaller the animal, the faster the shutter speed needed to freeze it.

There is one more technique that I had mentioned earlier which can improve the chances of getting a stable shot at slow shutter speeds. To recap, you should set your camera for a high-speed continuous shutter release mode. In this mode, most cameras will take around 3-5 shots per second. Since the camera will take 3-5 shots a second, there is a good chance that one of these might be blur free. Personally, I always use the high-speed shutter release mode excepting when using the flash, shooting still life or using a tripod.

Gently Does It!

This is a very interesting one. Believe it or not, most of us jab the shutter release button instead of gently “squeezing” it to take a shot. I used to do the same without quite realising it and still do the same at times. This adds a component to the camera shake and can result in blurry images.

All modern cameras have a two stage shutter button. A half press on the shutter button focusses on the subject and the next half press releases the camera shutter to take a snapshot. This second half press is where most of us have a tendency to jam down the button instead of “squeezing” it gently just as we do for the first half press for focussing.

There are no tips that I have for this issue. You will just have to practice on your own camera and figure out how gently you should push the shutter release button. I think this is a psychological thing when we jam on the shutter button to take a shot with a rush of adrenaline/excitement or hurry to get the shot before the scene changes.

Focus on the Subject!

A Small Hoverfly on a Tiny Sweet Alyssum Flower

Some area in sharp focus

Recall from an earlier discussion that the camera has no clues what you want to focus on. By default, the camera assumes whatever is closest and in the centre of the frame should be the point of focus. This is the second most common cause of blurry images. Even though the shutter speed is fine, the image is still blurry because the main subject is out of focus.

My recommendation is to use the single point focus mode of your camera and set the point to the centre point of the available focus points. This way, you will always have control of focussing on your main subject and not let the camera decide what to focus on. Consult your camera manual for the different focus modes it offers and how to set a single point focus mode.

It might be useful to keep in mind that only a small area of your image would be in focus and there is only one area of sharp focus. The aperture controls how much of the area would be in focus. The smaller the aperture (higher f-stop number) the more the area in focus and vice-versa.

Use this DoF calculator to figure out the area of focus in a variety of conditions.

Overall Exposure

If you have not gone through the earlier articles, then, go through this link explaining the “Exposure Triangle” first.

There is only one “correct” exposure for any given scene, but, as you would have seen from the “exposure triangle”, there are multiple ways of getting to the “correct” exposure.

Night red...

Creative exposure

In our case of trying to get blur free images and getting to know our cameras better, our highest priority is the shutter speed, followed by the focus and then the aperture. To get a high enough shutter speed, you would need to open up the aperture, depending on the available light. If you also want more depth of field (DoF) or more of the area in focus, then, the only option left is to increase the ISO. Keep in mind that increasing the ISO will also increase the noise levels in the image.

Let us assume that we are using the “P” mode and on half pressing the shutter to focus, the camera shows us that it has selected a shutter speed which might be too slow for the focal length of the lens in use, or, might not be good enough to freeze the subject. In such cases, you would increase the ISO (or set the camera to select ISO automatically) till you get a shutter speed that is high enough. Although you will never encounter this issue in normal daylight (bright & sunny) conditions, you will run into this in the early morning, late evening or indoor scenarios.

Unfortunately, as you will soon find out, even in the “P” mode, your camera will generally select shutter speeds that will not be good enough. Unless your camera has programmable shutter speed, the P and A modes will drop shutter speed, when needed, straight to 1/60th of a second and if you are not watching the shutter speed, then, you will land up with blurry images. Check your camera manual to see if it has an option for setting the minimum shutter speed. Most newer cameras (last 2-3 years) should have the auto options along with a flexible “P” mode.

Metering

This is also a topic we briefly touched upon earlier. This is a process where the camera “meters” or measures the light in a scene to arrive at the “correct” exposure. All cameras offer at least 3 methods of “metering” for light in any given scene.

So, which metering mode should one use? Like my recommendation of using the P mode, I would go with the fully automatic or evaluative/matrix metering mode of the camera. This works well in most scenarios. The lone exception is backlit subjects, where the light is coming from behind the subject. This is where you might want to switch to the “Spot Metering” mode of your camera. Do check your camera manual for more details on metering modes.

Exposure Compensation

Again, this is a topic we already had a brief on earlier. To recap, the camera will always try to meter a scene and adjust the exposure to a medium grey of around 18%. While this is fine for most scenarios, it fails when the scene is mostly white or black (actually the reflectivity of the scene/subject). For white (snow etc), you would need to dial in a positive exposure compensation which tells the camera to “over expose” so the white does not become grey. The reverse applies to black subjects/scenes.

Which Mode When?

There are certain fundamental rules to this decision. Well, it could be considered to be opinions as well. Let’s briefly look at all the four creative modes.

The P and A modes drop the shutter speed to 1/60th of a second when using the flash, pop-up or external. Keep this part in mind. 1/60th of a second will not be good enough for most common scenarios excepting studio or still life shots. Both these modes will also drop the shutter speed rather than the ISO to get the “correct exposure”. In these cases, you will need to watch the shutter speed and increase the ISO if the camera does not do that for you.

The PAS modes are equally good in brightly lit conditions, but, the P mode can adapt to different conditions automatically. The A and S modes would require you to adjust settings based on the light and scene.

The P Mode

This is the recommended mode for most scenarios of casual shooting, while keeping a watch on the shutter speed and adjusting the ISO or using the flash, as desired. This is also the mode you should always set the camera to when you are done shooting in any other mode. When shooting in changing light conditions, like early morning and late evening where the light changes fast, P is the way to go. This is also the way to go when shooting birds in motion as they might move from opposite the sun and go towards it with you in the middle. The exposure would change drastically within a second or two in this case. This might be too fast a change for you to be able to adjust to manually in the other modes.

In general, for all good light conditions, this is the recommended mode along with a high shutter release and a single focus point at ISO 100 to 200.

How you would handle low light scenarios would depend on your camera. If you can set the minimum shutter speed in your camera, then, along with auto ISO, the P mode will work fine across almost all conditions. Of course, you must remember to check and set your minimum shutter speed based on the focal length of the lens you would be shooting with.

The A Mode

This is the mode you would generally switch to on occasion once you are comfortable with the camera and using the P mode. The A mode enables you to control the depth of field (DoF) and the camera figures out the rest. This is desirable for a variety of reasons, two of which, we will look at now.

Every lens has a “sweet spot” where it will give you the best IQ (Image Quality) and you might want to shoot mostly at the aperture where your lens has the best IQ. An example which I already mentioned in this context was the Tamron 70-300mm lens that I bought initially. It was only at f/8 or higher that the CA (Chromatic Aberration) and the purple fringing came under control. You can find detailed information for your lens on professional lens review sites like DxOMark and some others.

I mentioned macro photography in an earlier article which is essentially extreme closeup photography. This represents one of the areas of photography in which you will always remain in either M or A modes.

There may be scenarios where you would want to switch to the A mode even for birds and bees and landscape as well as portraiture and we will look at some of these later.

The S Mode

Switch to the S mode when trying to freeze moving objects. Typical cases for this mode would be when you wish to freeze the motion of a flying bird or a moving car etc. The other scenario might be when you actually want some blur in the image and deliberately slow down the shutter speed. The most common example of using a slow shutter speed would be on running water. A longer exposure on water will give it a glass like look instead of frozen drops. The other, not so frequent, use is for night scenes where you would use a slow shutter speed of around 5-30 seconds to capture the skies & stars or car lights streaking across a road.

Besides these “typical” uses of the S mode, you might even want to switch to the S mode instead of P or A to control the shutter speed as you desire in certain scenarios.

The M Mode

This is the “Mother” of all the creative modes. This is the final, ultimate mode where you are in control and the camera only does your bidding!

Interestingly, this is also perhaps one of the simplest modes to use once you get used to your camera. While this mode might not be great for candid or for offhand shooting in changing light conditions, it generally works well under any condition. The catch is that you, as the person controlling the camera, knows exactly what settings to put in and when.

Always Shoot RAW!

Shooting in the camera raw mode has numerous advantages over jpg. Given the negligible cost of storage for the camera and the huge amount of processing power available to us on todays laptops and desktops, there is no excuse not to shoot in raw.

The raw image information allows you to manipulate critical tonal values with no loss in detail. Perhaps, the most common example of this is the “White Balance” of an image or a set of images.

Another advantage of raw is that you can turn off all the in camera optimisations like noise reduction, picture control, lens distortion correction etc. All of this processing can be done later, and generally better, in software on the desktop or laptop. This will enable to camera to shoot at the highest possible rate when using the continuous shutter release mode since there would be little to no processing done in camera for every image.

Summing it up…

Use the P mode. See if this is a “flexible” P mode in your camera that enables you to change the aperture by rotating a dial or something. Set the metering mode to matrix/evaluative, ISO to the lowest on your camera, generally 100, white balance to auto and go!

Parallel Pose :)

1/60th of a second with a flash

Watch the SS (Shutter Speed) at all times before releasing the shutter. Use the “flexible” P mode, if available, to open up the aperture or increase the ISO if the shutter speed falls below the 1/FL rule. In case your camera allows you to pre-set all these parameters, then, set the ISO to auto and the minimum shutter speed to auto or 1/FL.

Always keep in mind that in most cameras, the P and A modes will generally drop the shutter speed to 1/60th of a second when using the flash. Be mindful of this fact and act accordingly.

Without a reasonable camera holding technique and some stable surface to rest the camera on, getting blur free results at 1/60th of a second will be difficult when using a long lens. Of course, you would also have to keep in mind the subject movement factor at these slow shutter speeds.

Do not trust the LCD display on your camera for a correct representation of the raw exposure. The histograms are a much better representation of the exposure. The colour histograms (RGB) give a more accurate picture of clipping rather than the white, luminosity one. As for the IQ and blur, just zoom into the image and that should give you a fair idea about the image being blurred or not.

Also keep in mind that every image would require some post-processing. At a bare minimum, you would set the white balance, exposure, black & white points and perhaps some other tonal adjustments including some contrast and noise reduction. Consult the manual for the applications that came with your camera for more information on all of this.

Lastly, do not be afraid to bump up the ISO when the light is good enough, the noise on high ISO becomes more apparent only in low light scenarios. For example, even on a bright, sunny day, use higher ISO values to get high shutter speeds with the “correct” exposure to freeze motion like flying birds or moving cars in case ISO 100 or thereabouts does not give you a high enough SS. In my experience, you should be able to go to around ISO 400 without any major noise, although, some detail would be lost. On the entry level DSLRs that I have tried so far, anything beyond the ISO 400 level starts to show perceptible noise and loses detail. If details are not important in the shot, then, by all means go as high as needed on the ISO.

When uploading your images to Flickr or any similar service, make sure you title, tag and describe the image. Including the EXIF is also a good practice.

Think of yourself viewing someone else’s images without any title or description…What would this convey? I would say that it conveys a dump of images to such service for private use or restricted to a specific group or circle where people are already familiar with the image and know about it. If that is your goal, sure, leave out the information.

The EXIF information also follows the same thought pattern. Suppose you look at an image and really like it. The next question would be to look at the camera and settings used to create that image in order to learn from those. Then, you find there is none…One of the reasons for images not having EXIF information is that they were touched up in some application that removed the information.

In the next article, we will look at some aspects of composition. These are elements in an image that makes it more appealing to the human eye.

So, let’s go and shoot!

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Posted by on June 7, 2015 in Photography

 

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