Thursday, September 10, 2009

Buying Your First DSLR


Well, you’ve decided; you’re tired of the out-of-focus, motion-blurred, grainy snapshots you’ve been taking with your point-and-shoot, and are about to take the plunge – investing in a digital single lens reflex camera, or DSLR for short. The problem is, with such a dizzying array of options available, what should you be looking for? What’s important versus simply nice-to-have... and what really doesn’t matter at all?

Megapixel Myths

For years now, manufacturers have been touting megapixel count as the primary concern for would-be camera buyers. ‘Bigger is better’ they assert, even offering up 12 megapixel and higher products in the point-and-shoot arena.  While there are indeed certain advantages to a higher megapixel count, such as increased crop latitude and the ability to print on larger media, there are a variety of negatives as well to take into account:
  • The more megapixels you pack onto a sensor, the more noise you are going to get at higher ISO settings; i.e. when light conditions aren’t ideal, your photograph will be more grainy
  • More megapixels means more megabytes. This results in not only more storage space required on your computer, but also slower speed when processing these images, given your machine has to deal with more data
  • Lower frame rate (the number of photos you can take in a sustained burst) is a result of larger files – your camera can only process so much information at a time
  • A steadier hand is required at lower shutter speeds with higher megapixel cameras
Aside from the negatives listed above, the advantages preceding them aren’t that great. How big do you really want to print anyway? I’ve produced 13x19” prints from a 6MP file with no discernable reduction in quality. Consider what is arguably the best DSLR on the planet at present: the Nikon D3. This nearly $6000 CAD camera body (lens not included) has only 12.1MP at its disposal; yet produces stunningly sharp 20x30” gallery prints with ease from its files. Unless you’re printing billboards, you probably don’t need more than that.

What is important when it comes to megapixels is the ratio of them to the sensor size. What makes the D3 so impressive is that despite the huge, full-frame (23.9 x 36.0 mm) sensor it houses, the pixel count is relatively small – enabling it to produce nearly noise-free images in very low-light conditions.

Shooting in the RAW

If you’ve been using a point-and-shoot to date, you’re probably used to producing and working with JPEGs. Certainly, this image format keeps file sizes small and requires little post-processing; however, that’s pretty much where the benefits end. When moving up to a DSLR, ensure your camera supports RAW as well. RAW is a digital negative format which provides a number of advantages over JPEG:
  • No set white balance – if you screw up your white balance settings in-camera (say taking a photo under fluorescent light when your camera is set for daylight), you can change it to the correct value after the fact with no ill-effects
  • Greater latitude in exposure (i.e. higher dynamic range, or the range between highlights and shadows in your photo)
  • RAW is lossless – it’s what comes out of your sensor before being processed, while JPEG is a compressed, optimized version of that information resulting in data being lost which you can’t take advantage of after the fact... once it’s gone, it’s gone.
  • The higher available bit depth (often 12 or 14) in RAW files as compared to 8 bit JPEG images allows smoother tonal gradation, especially in shadows and highlights
  • RAW files can be reprocessed by new RAW converters as they become available, leading to potentially better and better results from the same image. A JPEG is a JPEG; what you see, is what you get, and every alteration can lead to a further degradation in quality.
On the other hand, the downside of RAW is that the images come out of the camera looking somewhat dull and not very crisp... they require processing. So, from a time perspective, this seems a disadvantage; however, given the greater level of control and superior end result after processing, most serious photographers feel the extra expenditure in time is well worth it.

Of course, if you have to process images, you’ll need a RAW processor. The best on the market at present (excluding camera manufacturer’s proprietary ones) include Adobe’s Camera RAW, which may be found at the heart of their Lightroom and Photoshop products, and Apple’s Aperture application. As these range between $200 and $700, it’s definitely a consideration to be factored in when purchasing a DSLR. Don’t let this dissuade you however if your budget is tight; there are also decent free RAW processors available, such as RAW Therapee (www.rawtherapee.com) which should get you up and running in no time.

Lens Lore

As you explore the world of DSLRs, you’ll come to realize that camera bodies come and go, but lenses are forever. A great lens is an investment that you’ll more than likely be able to sell for almost what you paid for it years down the line, while camera bodies rapidly decrease in value as new models become available.

When  buying your first DSLR, you’ll find many salespeople urge their customers to purchase an accompanying ‘kit lens’ – often a mid-range zoom with a variable maximum aperture determined by focal length. Examples would include Nikon or Canon’s 18-55mm f/3.5-5.6  which sell for under $200 separately. While the flexibility of the zoom is a great asset, these low-end lenses will soon find themselves in your junk drawer or on e-Bay given their limited utility.

Their primary weakness lies in the fact that as you zoom out, more light is required to make a good exposure; so in reduced light scenarios, you are forced to either decrease shutter speed (potentially introducing motion blur), or increase ISO (adding noise to your image). Additionally, your depth of field (the portion of the image in sharp focus)  choices are reduced, limiting your artistic expression.

A good rule of thumb is in most cases to never buy any lens that doesn’t have a constant maximum aperture of f/2.8 or less. While these lenses are considerably more expensive, they’ll serve you over a lifetime.  If budget is a constraint, a prime (fixed focal length) lens may be purchased for almost the same money as a kit lens, yet has the benefit of wider apertures and better glass... and you simply zoom with your feet. Great examples of this are the Nikon 50mm f/1.4 or f/1.8. The former is a pro lens which sells for under $400, while the latter is almost as good and retails at around $159. Cannon also has these lenses which are similarly priced though a little more expensive for the f/1.4 and a little less for the f/1.8. Not only are these lenses timeless, but they’ll actually teach you to be a better photographer as you learn to work around the limitations of fixed focal length.

Next time...


You’ll have noticed that thus far I’ve only been talking about Nikon and Canon – find out why in the next issue where we’ll continue our discussion on what you need to know when making your first DSLR purchase.

Originally published in TechKnow Magazine by columnist, Ray Richards,
August, 2009.

4 comments:

  1. This comment has been removed by the author.

    ReplyDelete
  2. If you want to buy your first DSLR than review some DSLR camera review for getting best resolution camera. I think that it must have the benefit to choice camera. Security Camera Reviews

    ReplyDelete
  3. Your site is truly cool and this is an awesome motivating article. Much thanks to you to such an extent. Zulma Razo

    ReplyDelete