Meet Sigma’s first ultra-telephoto zoom lens for full-frame mirrorless cameras: the 100-400mm F5-6.3 DG DN OS Contemporary lens. I spent a few months using this lens for bird photography. This review answers every birder’s most important question about a lens. As eloquently stated by my bestfriend, Janay: “Will I be able to see these birds eyeballs from my balcony or nah?”

Design

A “Handy Tele Master” that empowers your photography vision, anytime, anywhere.

SIGMA

Before I answer that, let’s talk about the design of SIGMA’s 100-400mm Contemporary lens. It’s like goldilocks for bird photography: long reach, compact body, and light enough to comfortably lift up and down for miles. The body is weatherproofed with a dust and splash resistant structure for outdoor protection.

It has four switches on its body that offers more control over focus and image stabilization. You can switch between its smooth, high-speed autofocus (AF) or manual focus (MF). A focus limiter switch restricts the auto-focus range to a specific distance while shooting. There’s also an autofocus lock (AFL) button that locks the focus and doubles as a customizable button for custom functions of your choice.

It has two optical stabilization (OS) modes to minimize small camera shakes. The first mode is made for shooting without a tripod. The second mode gets more aggressive for action shots. It “corrects for vertical shakes” so that you can pan the camera on a moving subject and prevent the stabilization algorithms from correcting it. Combined with a camera body with built-in image stabilization, the lens will correct for pitch and yaw axis rotations as well.

The SIGMA 100-400mm Contemporary features a “dual action zoom” setup to zoom by turning the hood of the lens (straight zoom) or using the zoom ring. Both options have a smooth pull with just enough friction to avoid lens creep. Last, and the most handy switch on any lens for most birders, is a zoom lock. It keeps the lens from accidentally extending and hitting the ground when you’re not using it and moving around.

Bird Photography Performance

Focal Range: 100 — 400mm

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Paired with the Panasonic S1R, the SIGMA 100-400mm Contemporary is powerful, sharp and yes, you can see the eyeballs of these birds from a comfortable distance. Before I get into what I enjoyed, I’ll start with my biggest gripe using this setup: autofocus. I leaned heavily on autofocus because this setup was heavier and longer than my personal camera and lens (Canon T2i and 55-250mm lens). On a scale of 1-10, I’d give its autofocus capabilities a 7.

Autofocus can be quick, but easily tripped up over patterns of grass or branches. To my surprise refocusing at significantly different distances is much slower, taking just long enough to miss a shot. I lost a fair share of opportunities for this reason. Case in point: the Blue-gray Gnatcatcher pictured above.

To work around this, I focused on other objects on or near the same plane of the bird I wanted to capture. A little annoying since birds are notorious for their disappearing acts. However, once this lens locked on a bird, the experience was everything you could want from a lens for bird photography.

FOCUS: Sharpness, Clarity & Detail

Across its focal range, the SIGMA 100-400mm Contemporary is sharp and detailed. As with all cameras, things start to go downhill in lower light or using slower shutter speeds when shooting without a tripod. Fortunately, there are plenty of photography tools to help recover sharpness.

Bokeh on Point

Despite my gripe, I did eventually capture that Blue-gray Gnatcatcher, a bird notoriously difficult to photograph because it never sits still. Here, the lens struggled to capture its face in full focus. However, you can see its eyes and details in the feathers. From its tail and beyond, there’s a satisfying bokeh that puts this buddy front and center.

Knowing how difficult it is to photography small moving subjects (like kids), it’s impressive how much detail the lens captured in this fleeting moment.

That Crop

Bird photography typically requires some amount of cropping no matter what lens you use. In the picture above, you can barely see the head of the Yellow-throated Warbler hiding in the branches. In fact, it could easily be mistaken for one of the leaves lit by the sun. When cropped-in, you clearly see its eyes and famed yellow-throat.

I have to hand some of this magic to the Panasonic S1R. It’s a high resolution (47.3MP) camera with an additional 187MP setting. When cropping, you’re reducing the resolution, which you want to keep high if you plan to print your photos. Cropping also risks degrading the quality of the photo. Starting with a high resolution gives you more room to crop and keep the resolution high enough to print down the road.

A downside to high resolution photos, especially if shooting in RAW, is having to edit RAW files that are 66MBs or more per image. The bigger the file, the more space it takes up and time it takes to edit.

Flaring & Ghosting

The SIGMA 100-400mm Contemporary lens features SIGMA’s Super Multi-Layer Coating to reduce flare and ghosting. For me, this coating worked really well because I didn’t experience either while shooting under the bright Miami sun. Regardless of the lighting and weather, it held up very well.

Using Teleconverters for Bird Photography

Teleconverters are an inexpensive way to extend the reach of a lens instead of buying a new one. Unfortunately, using them comes at the cost of added noise(grain) and darker photos because they increase how long it takes light to reach the camera’s sensor. With the SIGMA 100-400mm Contemporary and SIGMA’s TC-2011 (2x) teleconverter, the tradeoff was most noticeable when photographing birds in deep shadows on a bright day, like the original image of this redheaded woodpecker.

The 2x teleconverter doubles the reach of this lens to an impressive 800mm without adding a lot of weight or mass. Because of noise removal software, the edited version gives a much clearer picture of what was captured despite how dark the original looks. The bokeh is smooth and the woodpecker is clear and detailed. I also love how well the swirl in the contrasting feathers of its wing is captured.

The final product is free of noise, but getting there is an extra step that needs a decent amount of graphics power to process quickly.

Great Everyday Lens for Bird Photography

SIGMA’s 100-400mm F5-6.3 DG DN OS Contemporary lens hits the sweet spot for bird photography. It’s light, has an impressive reach, and great image quality. Though the autofocus could be faster when refocusing at greater distances, you’ll smile with pride at most photos taken with this lens. For the best shot at seeing the eyes of birds from your balcony, invest in the TC-2011 2x teleconverter ($399). While it brings the total cost of this lens from $899 to nearly $1300, it’s cheaper, lighter and has a longer reach than its big brother: SIGMA’s 150-600mm 5-6.3 DG DN OS Sports lens. Sigma also has a 1.4x teleconverter that’s $50 cheaper, but the 2x is worth the extra bucks to get that much closer to a bird’s eye.

What’s your favorite lens for bird photography? Leave a comment sharing why you love it!