Ultimate Image Quality

Photo © Derek DoefflingerThe two major goals to achieving ultimate image quality are image sharpness and ecstatic exposure. “Ecstatic exposure” means you get such a good exposure–one that reveals the widest possible breadth of detail from shadow to highlight–that you are ecstatic over the result. You’re ecstatic because with a good exposure you greatly increase your creative adjustment possibilities and minimize the tiresome and time-consuming software manipulations required to repair a poor exposure.In my recently published book, The Complete Guide to Ultimate Digital Photography, I address in great detail the principles needed to achieve these goals. In this three-part series, we’ll review those principles and show you how to implement them, but in somewhat less detail. By following the principles in each part, you can greatly improve your pictures. By following them all, you can reach, maybe even achieve, the cusp of ultimate image quality. Both understanding and enacting the principles are fairly simple. Follow them and you’ll soon produce photos worthy of your time and creative vision. For the most part, the principles focus on technical quality. Achieving creative superiority is up to you. But to truly realize your creative vision, you need to build it on the foundation of superior technical quality. As you will see in just a few short sentences, the principles tie together the many areas of picture taking that impact technical quality. Those many areas include using the right equipment, the right settings, the right handling and shooting techniques, and then the right processing and printing techniques. You need discipline to follow the process so you can reap the rewards.One more thought before we begin. You don’t need to follow these techniques for every photo you take—just the ones you really care about.The right cameraWhich camera should you use? This part is fairly easy, because you probably already have the right camera. That would be a digital single-lens-reflex (DSLR) camera. The differences between DSLR models are fairly small; almost any DSLR of eight megapixels or more will offer you the potential to achieve ultimate image quality (6MP cameras are okay if you do little cropping and don’t make prints larger than 8×10 inches). When ultimate image quality is your quest, avoid non-DSLRs—the snapshot cameras including the so-called prosumer models. Their image quality is inferior to DSLRs. They use comparatively smaller sensors and achieve their high megapixel specs by cramming tiny pixels (usually smaller than 4 microns) into an already small sensor. The problem? Tiny pixels (photosites that gather light) are relatively noisy, even at lower ISOs like 200, and create random colored speckles in the darker areas of your pictures. Digital SLRs use larger sensors with larger pixels that are almost noise free. Add in the commonly inferior lens quality of non-DSLRs and usual lack of the RAW file format (a few offer it), and you’ll see that a DSLR is the tool of preference.Although there are differences in image quality between different DSLRs, they’re usually fairly minor, especially at lower ISOs. Once you find a camera whose features and functions meet your needs, go for the highest megapixel rating you can afford. In DSLR land, more megapixels give you the versatility of greater cropping and greater enlargement. The right lensesChoosing a high-quality lens may be the most difficult–and the most important–of your tasks. It can be made considerably easier if you’re buying a new lens and willing to accept the advice offered in reviews at lens testing websites such as popphoto.com, slrgear.com, photodo.com, and photozone.de. These sites rate lenses a using variety of factors. The weakness from taking their recommendations is manufacturing variability, meaning other individual lenses of a particular model may not match the specs of the tested lens. You can test your own lenses, which we’ll briefly discuss in Part II.

Basis for comparison: Here’s a full-size comparison of photos shot with a better quality and lower-quality lens. See the difference? (The photo on left was shot with the better lens.) Photo © Derek DoefflingerWhen shooting to obtain ultimate image quality, avoid using zoom lenses with an excessive zoom range, those with a 5X range and above, such as an 18-200 or a 50-300 zoom. Most aren’t quite up to snuff for ultimate image quality. At the same time, consider a prime lens–a lens with a single focal length. Needing considerably fewer glass elements that mess around bending and altering light, these offer great potential for superior image quality.You might wonder if a lens with image stabilization would be preferred. The short answer is no—not for ultimate image quality. The long answer is yes—if you can’t discipline yourself to follow specific shooting techniques, or you expect to take most of your pictures not using ultimate image quality techniques.The right settings for the cameraYour camera likely has hundreds of settings and thousands of setting combinations. To keep things simple we’ll focus on just two settings: ISO and file format. Set the ISO to its lowest or second lowest setting to minimize—virtually eliminate—any noise. The one exception might be if you are photographing a moving object. In that case you need to set an ISO high enough to give you an action-stopping shutter speed.

This shot looks great small! But when it comes to ISO settings, the devil’s in the details…

…At 100% magnification, this detail of the shot captured at ISO 100 is looking good, but…

Look at all the digital noise (grain) when I shot the same scene at ISO 800! Photos © Derek DoefflingerYou certainly know what I’m going to tell you in choosing the file format. It’s RAW. The common alternative to the RAW file format is the JPEG format. But it uses compression to give smaller file sizes. That compression slightly reduces the quality, most often noticeable as slightly jagged edges along object and color borders or slightly off color pixels in large uniform areas, such as blue sky. It also forces you to correctly set a variety of other settings, such as white balance, exposure, and several camera presets like sharpening, saturation, jpeg compression level, etc.White balancing act: Use a setup similar to this one to set your camera’s white balance. Photo © Derek DoefflingerWith the RAW file format you can easily change a variety of important adjustments in software after taking the picture. These include white balance, exposure, saturation, and sharpening. The RAW file format lets you overcome many picture-taking shortcomings so you can achieve good color and an exposure that maximizes detail from shadow to highlight.The right settings for the lensThe most important lens setting is the aperture or f/stop. Ignoring its creative effect, the right f-stop can minimize a variety of lens flaws, such as chromatic distortion, spherical aberration, and vignetting while maximizing the quality most important for most photographs—sharpness. What is the magical f-stop that can work these wonders? You can know that for certain only by testing your lens but invariably it’s a mid-range f-stop, most commonly f/5.6 or f/8 for a wide-angle lens, and f/8 or f/11 for normal and telephoto lenses.

On the right track: A brick wall or any subject that’s flat and has hard lines is a good test subject to help you determine if your lens is up to snuff. But image quality also changes as you change the aperture setting…

A little fuzzy: This was shot at f/4, which is outside the lens’s mid-range “sweet spot.” It shows.

Looks sharp: F/8 tests out as this lens’s sharpest aperture. Photos © Derek DoefflingerIf you’re using a zoom lens, try to avoid the maximum and minimum focal lengths (lens review sites often provide information about a particular lens’ best focal lengths). For instance, with a 17-70 zoom lens, you might want to use focal lengths between 20 and 65 mm (rather arbitrary starting and ending points on my part).

For over twenty years, Derek Doeffinger worked at Kodak writing about photography to help amateurs and professionals alike take better pictures. He’s been involved with digital photography since its onset in the early 1990s. His book credits include a variety of how-to and photo travel photo books. Among them are The Art of Seeing, Kodak Pocket Guide to 35 mm Photography, The Magic of Digital Printing, The Complete Guide to Ultimate Digital Photography, Waterfalls and Gorges of the Finger Lakes, and Finger Lakes Splendor.