Tennessee Photography by Bradley Proctor

There are a number of things that can improve your images while in the field and during post-processing of your files.  Not every situation will allow you to use all of these suggestions and in many situations you will find it hard to use only a few of them.  Most of this applies towards photographing still images where you have time to setup the shot.

Using a Tripod

Unless you are shooting at high shutter speeds a tripod will help you get sharper images.  The rule of thumb (at least in the old days) for shooting without a tripod is if the inverse of the lens focal length (on 35mm) is the minimum shutter speed to get a sharp image.  In simple terms,  this means with a 50mm lens you need a shutter speed of 1/50 of a second or faster to get a sharp image.

However, current technology has made this rule of thumb a little more complicated.  Image stabilization built into camera lenses (and some camera bodies) has made it possible to shoot as much as three stops slower while maintaining sharp images.  This means that in theory, with a 50mm lens with good image stabilization you should be able to shoot at about 1/8 of a second and still have a sharp image.  This of course also depends on your ability to hold the camera steady and does not help with moving subjects.

On the other hand, sensor quality has improved quite a bit in recent years and surpassed film in terms of image quality.   Because of this high image quality and fine detail that is possible with today’s sensors, the old rule of thumb doesn’t work quite as well as it did before.  A better, although not as easy rule for current DSLRs when image stabilization is not available might be half the inverse of the focal length.  So for a 50mm lens hand holding at 1/100 of a second or faster.  Still, give or take depending on your ability to hold the camera steady.

When using a tripod you no longer have to worry about if your shutter speed is going to be fast enough (unless of course you are shooting a moving subject).  Setting up a tripod also forces you to slow down and take your time to properly compose your image.  When you use a tripod you open up the possibility to use many more of these tips that can give your images better quality that would otherwise not be possible such as using a low ISO, stopping down your lens, etc.  There are other benefits besides just image sharpness like the ability to frame your image perfectly and make fine adjustments, shooting perfectly matching frames for panoramas, multiple exposures for HDR, special effects with long exposure such as the silky smooth water look found in rivers and waterfall shots and much more.

Using Mirror Lockup

The camera has a mirror that reflects light coming in through the lens up towards the viewfinder.  When you press the shutter button, the camera first flips the mirror up then the shutter opens, then closes, then the mirror comes back down after the shot has been taken.  The mirror is relatively big and heavy and when it flips up it can cause the camera to vibrate even when on a sturdy tripod.  This can cause your images to have a little bit of motion blur in them.  This is most noticeable at certain shutter speeds, usually around 1/2 second or so.  If you have your camera on a tripod then the next step is to use mirror lockup.  What mirror lockup does is locks the mirror up and then takes the picture after a moment or until you press the shutter button a second time.  This allows for any vibration from the mirror movement to die down before taking the shot.

Different cameras turn this option on differently.  On Canon DSLRs this option is turned on through the custom settings menu.  With mirror lockup turned on, the first time you press the shutter the mirror flips up and the second time you press the shutter the picture is taken.  When using mirror lockup I almost always have a two second delay timer set as well.  When the timer delay is setup as well as mirror lockup, the camera first flips the mirror up when the shutter is pressed then after two seconds the picture is taken.  This is how I usually shoot.

Using the timer or remote shutter release

A remote shutter release or using the timer can help to further reduce camera vibrations.  When you press the shutter button it causes the camera to move no matter how careful you are.  With a remote shutter release or by a delay with the timer you can avoid these vibrations.  This is often used in conjunction with mirror lockup when the camera is mounted on a tripod.  I usually use a 2 second delay timer rather than a remote shutter release because the cord can be a pain whereas the timer is built in to the camera.

Using the native ISO

If you are using a tripod, have mirror lockup more than likely you are shooting a still subject.  In this case it is best to use the cameras native ISO.  The native ISO is usually (but not always) the lowest ISO setting.  The Canon 5D MkII has the ability to shoot at ISO 50 even though it’s native ISO is 100.  The native ISO will give you the least amount of noise in the image.  An ISO below the native ISO such as ISO 50 on the Canon 5D MkII is identical to ISO 100 but is useful for when you need a longer shutter time.  However, when using a lower ISO than the native ISO you lose dynamic range in the highlights.

Using the optimal aperture

When you use the optimal aperture for a lens you get the sharpest image.  This optimal aperture will vary depending on the lens but it usually is in the range of f/5.6 to f/8.0.  You may have heard the old saying “f/8 and be there.”  This is basically saying to get good shots, set your camera to f/8, and be in the right place at the right time.  Of course, there is more to it than that, but it is good advice nonetheless.  When the aperture is wide open, more of the lens glass is being used.  Typically lenses have a sweet spot near the center of the lens where the optics are the best and imperfections occur the further out towards the edges.  Closing the aperture down to this sweet spot will give the best image quality.  However, if you reduce the aperture too much defraction becomes visible.  Defraction is when light hits the edges of the aperture blades and bounces off at another angle.  This causes the image to appear out of focus.  Defraction occurs in every image but the wider the aperture the less the defraction is visible in the image.

To find the optimal aperture for your lens, setup a test chart and hang it on a wall.  This can be any image with find details and high contrast.  Put your camera on a tripod and make sure that it is as perpendicular to the test chart as possible. Use the recommendations in this article to get the sharpest possible shot by using mirror lockup, the native ISO, the timer or remote shutter release, shoot in RAW, etc.  Take several shots at different apertures and make sure you are properly focused.  Next bring them into Photoshop, Lightroom, or whatever else you use and compare the images at 100%.  You should be able to tell right away that shots around f/2.8 are not as sharp as the ones at f/8 and also that f/22 is not as sharp as f/8.  To find the optimal aperture takes some really close looking and you may find that there isn’t enough difference between f/5.6 and f/8 that it matters.

Using ETTR (Expose To The Right)

Expose to the right is a concept that means on a DSLR you should overexpose your images when possible but not let the highlight clip.  Then later when post processing bring the exposure down to the desired level.  The reason behind this is that the camera is able to capture more detail in the highlights than it can in the shadows.  Quite a bit more in fact.  Because of the way f/stops and how we see light are on a logarithmic scale while brightness levels in binary form in the camera are on a linear scale the bits of information stored in the digital image are not distributed evenly.  The newer DSLRs are 14-bits.  This means that they can record a total of 16384 brightness levels (of each color channel).  Half of all of these brightness levels go to the first f-stop.  Half of the remainder go to the second stop and so on.

As you can see from the chart, the darker the image, the less information the camera is able to capture. Because of this it is best to try to overexpose slightly to get as much color information as possible without clipping the highlights.  For an in depth explanation of this visit http://www.luminous-landscape.com/tutorials/expose-right.shtml

Using RAW

When you shoot in JPEG, the camera gathers the RAW data from the sensor, processes it and makes some quick decisions based on your preferences and outputs a JPEG in a blink of an eye.  This conversion also reduces the bit depth down to 8 bits per channel and compresses the color space into either sRGB or AdobeRGB.  The JPEG is also a lossy compression format which means that it is throwing away information to create a smaller file.  JPEG out of the camera has a lot going against it.  However, you also have the option to save the RAW data from the camera without any further processing done to it.  This allows you to bring the RAW data onto a computer to do the rest of the processing.  Because it is being done on a computer the RAW convert software can be much more complex and accurate and because you are working on the image you have the ability to make decisions about how the image should be processed.  If you don’t like something you can always process the RAW data again.  This isn’t possible when shooting in JPEG as the camera throws out the RAW data as soon as the JPEG is created.  There are a whole host of reasons why shooting RAW is better than shooting JPEG. However, there are some reasons you might need to use JPEG such as if you are shooting quick shots that you do not intend on doing any post processing on or you need to use the images right away.  With software like Adobe Lightroom, it makes working with RAW images a breaze.  My past article, RAW vs JPEG explains more about the subject.

Using ProPhotoRGB

Color Management is a broad topic that is well beyond the scope of this article.

When you shoot in JPEG there is an option on most cameras to specify the color space that you want your image to be in.  Usually the options are sRGB or AdobeRGB and sRGB is most often the default.  Setting it to AdobeRGB allows you to capture more of the colors that may have been in the scene because it has a larger gamut.  If you decide to shoot JPEG, you may want to consider setting your camera to AdobeRGB.

When shooting in RAW, a color profile is not associated with it until it is processed by the RAW converter (so the sRGB/AdobeRGB setting in your camera doesn’t matter).  The way this is done varies depending on what RAW converter you are using.   Saving your image in ProPhotoRGB color space allows you to get the most out of image without having to compress the color space.  However, if you do save it in ProPhotoRGB, it is recommended that you also save the file in 16-bits per channel.  This is because the ProPhotoRGB color space is so large that in 8-bits per channel banding can occur.

Using 16-bit files

When you are shooting RAW your image will typically be 12-bit or 14-bits. Saving the file as a 16-bit TIFF or PSD file allows you to retain all of that information when you are working on it in Photoshop.  If you save it in 8-bit you are truncating the data and losing color information that was in your original image.  When doing a lot of post processing on your images it can be important to be using 16-bits per channel.  Every time a modification is made to the image rounding errors occur. For example, if you had an 8-bit image and a particular color had a brightness level of 221 for the red channel. You now decide to set the brightness to 50% for this color. Because 221 does not divide evenly it will end up being rounded to 111 when it really should be 110.5. Eventually, enough rounding errors can cause posterization in the image. This is where you can see the color break instead of a smooth transition between colors. To avoid this, using 16-bits per channel allows for 16384 brightness level instead of only 256. This gives you a lot more room to play with before this becomes a problem.  Rounding errors still occur, but their impact is much smaller.