Digital SLR Buying Guide

Without getting too technical, a digital SLR offers better picture quality, faster shutter response, and more in-focus pictures.

• Better Picture Quality: Digital SLRs offer superior image quality due to the higher quality of their lenses and their much larger image sensors. Both contribute directly to much improved picture quality. While any camera (even iPhones) can take nice pictures on a sunny day, digital SLRs perform significantly better in low lighting conditions, due to its larger image sensor size and the larger and faster lens which gather more light for better imaging.  And contrary to popular belief, picture quality is not all about the number of megapixels, as I will discuss later.
   
• Interchangeable Lenses: The inherent design of the digital SLR allows you to select the lens that suits your photography style and budget.
   
• Creative Control: Photography is an art and a science. Digital SLRs offer much more direct access to camera functions that provide that creative control.

Any objective guide will tell you that there are disadvantages:

• Added weight and bulkiness: Compared to point-and-shoot cameras, the smallest and lightest entry-level digital SLRs still adds considerable weight and bulkiness. Depending on your personal preferences, you may not mind carrying a camera bag for a digital SLR and associated gear. For some, a pocket-size point-and-shoot camera is the way to go. Check out a digital SLR in a retail store, pick it up, image and think about whether you would lug such equipment around all day, in addition to doing the usual things that you would normally do.
   
• Reflex mirror noise: The clicking mechanical noise of a digital SLR camera when you release the shutter is caused by the reflex mirror going up (and eventually down) so that the light bypasses the viewfinder and hits the image sensor for digital image recording. (Starting with the D5000 in 2009, Nikon has added a Quiet Shutter mode to minimize this noise. This feature is carried forward in the current D3100 and D5100 models with further improvements in lowering noise levels.) Another option is to consider mirror-less cameras that eliminate this noise completely (they are relatively compact like the point-and-shoot) but adds the flexibility of interchangeable lens.

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What Is Important?

Picture Quality

Digital SLRs have larger image sensors which results in better picture quality. Despite what other may tell you, picture quality is not all about the number of megapixels a camera has. While the image resolution (megapixels") contribute to the overall picture quality, other factors such as the size and quality of the image sensor and the lens play a bigger role in picture quality.

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Image Sensor Size (APS-C Size vs. Full-Size)

Both digital SLR image sensor sizes are larger than those of point-and-shoot cameras. The light gathering area is greater, yielding higher sensitivity for improved color rendering and lower image noise (particularly in low light).

Size comparison between the APS-C and Full-Size image sensors
 

APS-C sized image sensor (Nikon DX-format)

Full-Size, 35mm equivalent image sensor (Nikon FX-format)

Is bigger always better? If you are a professional photographer or a very serious amateur, the Full-Size image sensor format may be your cup of tea, as it offers the best, uncompromising image quality. However, if you are a casual amateur photographer, the APS-C format might do better. The smaller image sensor means a small optics path, yielding a smaller and lighter camera and lens system (which is better if you have to carry it around all day or on travel). Sure, it is a slight trade-off for image quality, but it is also a smaller hit to the wallet. Therefore, most amateurs upgrading from a point-and-shoot camera would opt for the APS-C format digital SLR cameras.

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Lens Quality

One of the novelties of the digital SLR design is the ability to interchange lenses. Both Nikon and Canon offer a wide variety of lenses for their respective digital SLRs. A key characteristic of lens design is its focal length. The shorter the focal length, the wider the angle the images take in. The longer the focal length, the narrower the angel the images take in (and magnified like a binocular). Most amateurs venturing into digital SLR cameras should focus on the APS-C column in the table below for the effective perspective of lens focal length.

When you buy a digital SLR, you can either buy the camera body by itself, or buy the camera packaged with a "kit lens" selected and pre-bundled by the manufacturer. The "kit lens" is relatively inexpensive and intended to get you started right away, and most are surprisingly good. For example, the Nikon 18-55mm zoom lens that is included as part of the Nikon D3100 kit is surprising good. Most of my pictures on this site was taken by that lens (and my Nikon D5000). For some photographers, this basic but very capable lens is all they will ever need. Its light weight and compact size makes it a good candidate lens for every day use and travel.

As a final note, lenses are not interchangeable across camera brands (Nikon, Canon, Sony). Each manufacturer has its own proprietary lens mounting system. Therefore, once you chose a brand, you will want to stay with the same brand because of the compatibility (or lack thereof) of lens, flash units, and other accessories. Third-party vendors (e.g., Sigma, Tamron, Tokina) also make compatible lenses for each manufacturer.

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Image Sensor Resolution (okay, finally "megapixels")

Yes, megapixel count is a measure of the image sensor resolution. Typical resolutions are 10, 12, 14, and 16 megapixels for consumer level digital SLRs. But don't get caught up in what I call "megapixel envy", because 12 megapixels is plenty enough to produce 14" x 20" prints and will fill more four times the display area of most computer screens. (Even National Geographic photographers don't need much more than 12 megapixels.)

Instead, focus on image sensor size and quality lenses if you want the best picture quality.

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If you have been using a point-and-shoot camera, you love the fact that it is small and very portable, and is easy to use. While digital SLRs are much bigger than point-and-shoot cameras, these considerations are likely to remain important to you. And with digital SLRs, chances are you will be shooting pictures much, much more, so ergonomics is going to be important.

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Going from a point-and-shoot camera (weighing around 0.5 - 0.7 pounds) to a digital SLR will be immediately apparent from a weight standpoint, as even the lightest entry-level D-SLR coupled with a simple, light lens will come in around 1.5 pounds. Some professional D-SLRs with a professional-grade lens weigh in over 4 pounds. For the amateur photographer, when it comes to weight, less is more. You will definitely feel the difference after lugging around a digital SLR around for a day.

Most digital SLRs are similar in terms of layout: the right handgrip (with the shutter release button on the top), the SLR characteristic pentaprism hump at the top center. However, there are subtle differences in the plastics used to mold the body and the handgrip and other areas where your hands would normally fall to operate the camera. Be sure to pick up and handle the different digital SLR camera bodies in the store. Ask to handle it with the lens that you're most apt to buy/use. The lens affect the overall balance of the camera body/lens as a system.

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The color LCD display is a key part of the user interface experience, just like on the point-and-shoot cameras. Look for larger displays, up to 3" diagonal, and higher resolution (typical is 260,000 pixels vs. state of the art 921,000 pixels) for better review of your images.

Nikon D3100's 3" LCD display

Some digital SLRs feature an articulating LCD screen (Nikon D5000/D5100, Canon 60D), allowing you to compose pictures below (close to the ground) or above your eye level (over people's heads).

 

Nikon D5100's articulating 3" LCD display

An articulating display allows you to compose pictures at low angle or high angle, allowing flexibility and creativity

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To set up and control the camera, there are dedicated buttons for some functions, but most functions are only accessible via a on-screen menu system. On professional level digital SLRs, there are many more dedicated and programmable button that allow a professional photographer direct access to commonly used functions. When you work with a camera for a whole day, day in and day out, these productivity enhancements make a big difference.

Look at the layout of the buttons, and evaluate how well you can reach them while holding the camera. Your right hand goes on the handgrip with the index finger on the shutter release button and the thumb on the right side of the back panel. (Your left hand should support the bottom of the lens (with the palm facing up), and be able to rotate the zoom ring.) Can your right thumb access the exposure lock buttons on the top right of the back panel? What about the control knob on the top right of the back panel? You should be able to make these adjustments while still maintaining a firm grip on the camera with both hands. Ideally, you should feel comfortable with the layout of the camera as if the camera were an extension of your hand. It should be second nature, such that you can make adjustments without having to take your eyes off of the camera viewfinder. Understandably, it would be hard to assess ease of use and usability with a short trial in the store. And each person has his/her unique preferences.

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First of all, digital SLRs are no different from 35mm film SLRs. Back in 1985, when I started my hobby with 35mm film SLRs, professional photographers have said that the image quality is mostly attributed to the quality of the lens. One went as far as to say that the SLR body is "merely a lens holder". How true that might have been back in the day of 35mm film. With digital imaging technology, there is some truth to that, but what's changed is that the digital imaging sensor plays a more important role, as we have discussed before with image sensor size.

Manufacturers like Nikon and Canon have a knack for developing a state-of-the-art image sensor for their high-end professional or prosumer digital SLRs, then all too quickly they reuse the same high quality imaging sensor for their lower-end cameras. For example, in the Nikon line, the prosumer D300s ($1700) 12.1 megapixel image sensor was reused in the D5000 ($850), with the release of the latter within months of the former. Of course, you don't get all the other bells and whistles that come with the higher-end camera. But unless you are a very serious amateur, you might not even miss it.

It stands to reason that with the "trickle down" technology, you can a really good camera with a great image sensor at entry-level prices. For most photographers upgrading from point-and-shoot cameras, the sweet spot is the Nikon D3100 ($534 @ Amazon.com with the Nikon 18-55mm kit zoom lens) or the Canon T1i ($600 @ Amazon.com with the Canon 18-55mm kit zoom lens).

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Where to Buy? Support This Site

References:

• Nikon USA: Nikon FX/DX format discussion
• Canon USA

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