Buying DSLR Lenses

One of the most commonly asked question I've been asked about Digital Cameras is dealing with lenses. Which Lens, what range and how much. If you are buying a lens for film this is still a tricky question but for digital this is further compounded as it all depends on your sensor size. When it comes to the size of lens to get this factor will greatly affect the effectiveness of your lenses focal length ... as many of you are aware a 50mm lens isn't always a 50mm lens. This is due to the fact that many Digital SLRs have sensors which are about 1/3 smaller than 35mm film. This is referred to as a Focal Length Multiplier or more correctly an FOV (field of view) Crop.

This smaller sensor is why when buying a lens you have to pay a lot of attention to what its intended use is. Many cameras have an FOV Crop of 1.5 or 1.6 meaning that a 50mm lens will in essence be the optical equivalent of a 75 or 80mm respectively. Buying the right lens is crucial ... many photographers who are starting out with digital cameras will buy the lenses which are bundled with the DSLR.

Major bit of Advice #1 - Don't buy digital lenses unless you plan to sell on your lenses with the camera when you upgrade (unless of course you upgrade to a camera which will be compatible with your lenses).

My recommendation is that you buy lenses which are designed for full frame sensors especially if you want to focus on landscapes and portraits. This kind of buying will ensure you have full use of your lenses when you upgrade to a full frame based DSLR. My basic assumption here is that most photographers will eventually seek to upgrade to full frame sensors at some time in the future.

Major bit of advice #2 - When you decide to upgrade and can afford it - upgrade to a full frame sensor based camera ... currently only Canon have cameras such a sensor based on the 35mm frame size. Remember this though, your lenses will only be compatible if you buy with the future in mind.

In Canon EOS based DSLRs there are two lens types available: EF and EF-s type lenses. EF-s type lenses are designed specifically with a handful of Canons D-SLRs in mind and these lenses are not interchangeable with earlier models or full frame or 1.3 FOV Crop based models because of the depth of their rear optical elements. Using an EF-s Lens on an incompatible unit will most likely damage the Camera. This is one reason why I usually recommend buying an EF based lens.

Major bit of advice #3 - Do your research...
There are many ways to do this and besides the most obvious which is to go to a store and try out the lenses directly (which requires that you know what you are doing) there are some excellent resources online for getting some preliminary answers.

Basic Lenses to aim for -
50mm 1.4 or lower for standard and lowlight shots.
A 24mm for wide angle shots,
A 100/105mm for portraits and for an added bonus ensure it has a macro capability
A decent zoom lens in the 70 or 80-200 or 300mm range f4 will do to begin and if you can afford it better.

Bear in mind that you have to consider the FOV Crop

For excellent lens reviews try DPReview and Fred Miranda.

Where to buy ... See #3
There are many merchants out there who provide excellent service and who have been around for a while. Sure you can save £5 or more with some site or other but far too often these are fly-by-nighters who will abscond with your and lots of other peoples money ... so do your research and look for sites which will provide you with near instant feedback to your questions ... a site which will respond in 48 hours is just so much crap and if you run into a problem with the kit you will most likely not hear from them at all ... Don't buy from ebay unless the seller has a decent and long time track record and a lot of positive ratings.

In the UK, I've bought from Jessops and believe it or not Amazon.

You can also try other suppliers like Warehouse Express and Pixmania.

You can also vet dealers or check prices by visiting Reseller Ratings, Kelkoo or Pricegrabber.

Last thing I want to cover has to do with Brand versus third party lenses … I can only say here, that if you can afford to buy L series glass stick with Canon Lenses. Likewise with Nikons best glass. However if you, like many, are on a budget then by all means look at the Lenses produced by Sigma and Tamron for your Camera. Many of these have been reviewed at sites like DPReview and Fred Miranda already mentioned above.

I hope this has been useful …

For some excellent technical articles and info -
Steve Hoffmann's Nature and Lanscape Photography.

For an Excellent Reference of Digital and photographic Terminology visit DPReview.