Sigma Lenses for Digital SLR Cameras

Sigma makes some interesting lenses for digital SLR cameras. A Sigma lens can be an intelligent choice for owners of Canon small-sensor cameras such as the Canon Digital Rebel XT or EOS 20D and owners of any Nikon digital SLR. The following Sigma lenses are covered in this review:

• Sigma 30mm F1.4 EX DC HSM: a normal lens for every day and dim light photography
• Sigma 18-50mm F2.8 EX DC: a replacement for the cheap zoom lens that was included with your camera kit; this one will have better capabilities indoors
• Sigma 10-20mm F4-5.6 EX DC HSM: dramatically wide angle zoom lens
• Sigma APO MACRO 150mm F2.8 EX DG HSM: a good portrait lens and also capable of taking pictures of very small things

[Note: Except for the 150 macro, the Sigma lenses reviewed in this article will not work on the full-frame sensor cameras such as the Canon EOS 5D or 1Ds. The "DC" lenses don't cast a large enough image to cover a 24x36mm sensor or strip of film.]

The 30/1.4: A Normal Lens for Low Light Photography

Most of the world's great photographs were taken with fixed focal length lenses, not zooms. Partly this is because fixed or "prime" lenses are higher in every aspect of optical quality. Partly this is because a photographer with only one focal length available trains his or her eye to look for compositions that will be effective with that focal length. The "normal" perspective lens is the easiest for most beginners, because the perspective is similar to what one sees with the naked eye. On a 35mm film camera or full-frame sensor digital camera, the normal lens is a 50mm. On a small-sensor digital SLR camera, e.g., Canon Rebel XT or Nikon N70s, the equivalent would be a 30mm lens. Nikon and Canon both make wonderful 50mm prime lenses, but neither company makes a 30mm prime lens. That's why this Sigma lens, which costs around $450, is such a great find.

If your kit zoom lens has a maximum aperture of f/4, that means you will need 8 times as much light to take a photo as you would need with the Sigma 30/1.4 set to f/1.4. With your kit lens, you must turn on the flash indoors, blasting everyone with an unflattering central light. With the Sigma, you keep the flash off and capture the light that you see with your eyes.

One added bonus of the Sigma 30/1.4 is that it has an "HSM" or "hypersonic" motor. This is equivalent to Canon's "USM" (ultrasonic motor) or Nikon's "SWM" (silent-wave motor) and allows the photographer to use autofocus, but adjust the focus manually if desired.

Buy it now on amazon.com: Canon mount | Nikon mount

[Canon and Nikon both make prime lenses in the 35mm size, but they are designed to cast an image large enough for a film camera or full-frame digital. The consequence is that they are either very slow, with a maximum aperture of f/2 or f/2.8, and therefore require much more light than the Sigma, or they are very heavy and expensive.]

The 18-50mm F2.8: if you like a mid-range zoom, let it be a good one

The kit zoom lenses are too slow, with maximum apertures of f/4 or f/5.6, and too cheap optically. The consequences are that you need to use a flash more of the time and your pictures lack contrast and sharpness. The best solution to both problems is a set of prime lenses, but these can be cumbersome to carry around and change. If you like the idea of a single zoom lens for walking around, the Sigma 18-50mm F2.8 EX DC is a reasonable choice at around $500.

Canon does not make a lens like this. Their fast f/2.8 zooms tend to be designed for film and full-frame sensor digital cameras such as the EOS 5D. Nikon makes a 17-55/2.8 lens that is very high quality, but it is more than twice the price of the Sigma (check it on amazon).

This range of focal lengths is good for photographing a wedding reception or other social event.

Buy the Sigma 18-50mm F2.8 EX DC now on amazon.com: Canon mount | Nikon mount

The super wide angle zoom (10-20mm F4-5.6 EX DC HSM)

If you want to experiment with ultra wide angle photography and not spend more than about $500, the Sigma 10-20 is a reasonable choice. The Canon and Nikon equivalents either don't go as wide, are more expensive, or both. Because of its slow maximum aperture, f/4 to f/5.6, this is a lens to be used outdoors or on a tripod. [If you have a Canon Digital Rebel or similar small-sensor Canon EOS body, and can stretch your budget to $700, the Canon 10-22/3.5-4.5 zoom lens is a better performer.]

Buy the Sigma 10-20mm F4-5.6 EX DC HSM now on amazon.com: Canon mount | Nikon mount

The Sigma 150 Macro/Portrait Lens

If you are serious about taking pictures of people or pictures of small objects, you will want a single focal length or "prime" lens. The longer or "telephoto" macro lenses can serve both roles. Canon and Nikon both make some long macro lenses with fabulous performance, but they cost more than $1000. Sigma's is excellent and only around $600.

A shorter macro lens, e.g., 60 or 100mm, will be cheaper, but you'll need to get closer to your subject. In the case of hummingbirds and insects, this might well be so close that they become disturbed. A shorter portrait lens will also be cheaper, but won't flatten your subjects features in as flattering a manner. The bigger your subject's nose, the farther away you need to stand when taking the picture and therefore the longer lens you need.

This lens permits focusing down to a 1:1 image size. This means that you can take frame-filling pictures of objects as small as the film or digital sensor on your camera. If you have a small sensor camera, objects as small as 15x22mm in size will fill the frame.

Note that this lens covers a full 24x36mm frame and therefore will work on any digital or film SLR, including the Canon EOS 5D.

Buy it now from Amazon: Canon mount | Nikon mount

The rest of the Sigma line

I'm not a huge fan of third-party lenses. In general, Canon and Nikon make the best available lenses for their respective camera bodies. The really cheap Sigma lenses aren't very good optically and may have rather flimsy mechanical construction. The lenses that I have recommended here are midrange in price, are well made mechanically, and plug gaps in the Canon and Nikon lens range.

Readers' Comments

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SALVATORE PEDI , May 25, 2008; 02:10 P.M.

Taken from the very rear of the theater.

A few months ago, I went down to B&H in NYC to buy a lens for my Canon Rebel XT. I told the lens clerk that I wanted a lens that I could use in the theater with very low light conditions, and of course no flash can be used there.

He showed me the Sigma 18-200 3.5 OS lens. I told him it was simply too slow (f3.5 lens) for my purposes. When he then told me it was also an "Optical Stabilized" lens and that I could gain two or three shutter stops, I became interested.

A few days later I went down to Town Hall in NYC and started shooting away at all the Broadway singers and dancers on stage. I was sitting in the very rear of the theater which depressed me. I had to zoom all the way in to 150/200mm in order to get decent shots.

Depressed still, that night when I got to my computer, I was totally amazed at what I saw. Most all of the shots (250) came out wonderful. It actually looked like I was practically on the stage taking the photos!..

I'll enclose some photos to show you what the shots looked like. Needless to say, this Sigman lens stays on my camera all the time now. I would never had thought that a 3.5 lens would allow me to get such great "low light" shots.

Leo Kenney , May 27, 2008; 09:50 P.M.

I need to get a 24-70mm f/2.8 lens for wedding and group shots and use a fuji S5 Pro. I would love to get a nikon but at $1700+ I would have to remortgage the house. In your opinion is the Sigma a worthy alternative until cash flow allows me to buy the Nikon? The reviews I've read are favorable on the whole, but mixed. I've read that it is everything from soft to super sharp.

etienne poisson , June 18, 2008; 08:45 P.M.

Great picture but it's kinda noisy. All you need now is a better camera. Cheers