Sigma APO 50-500mm f4.5-6.3 DG OS HSM Lens

You get the idea from the latest Sigma lens releases that they are after some sort of “Guinness Book of Records” listing by being first to release the most “something” lens in every category. The Sigma 10–20mm f/3.5 is the fastest fixed-aperture lens in its range and the 8–16mm is the widest lens available for APS-C sensor cameras.

The Sigma APO 50–500mm f/4.5-6.3 DG OS HSM continues in this tradition by being the highest zoom ratio lens (10X) that reaches 500mm. Tamron’s 18–270mm still holds the record for longest zoom range (15X) and both Tamron and Sigma have 11X 28–300mm lenses.

The new Sigma 50–500mm f/4.5-6.3 upgrades their previous 50–500mm f/4-6.3 with Sigma’s proprietary optical stabilizer (OS) system, closer focusing and a new optical design with two additional lens elements. Sigma’s “DG” designation signifies that you can mount this lens on a full-frame film or digital camera or an APS-C sized digital camera. The “HSM” designation means that the lens incorporates Sigma’s Hyper Sonic Motor that provides fast and reasonably quiet focusing along with full-time manual focusing capability. Sigma’s HSM is similar to Nikon’s AF-S and Canon’s USM designations. The lens is available in Canon, Nikon, Pentax, Sigma and Sony mounts.

The lens is not parfocal, so the focus changes when the lens is zoomed, so it is not a true “zoom” lens. I don’t have a problem with this, but I mention it because I know of photographers who do. Focusing is very quick with little hunting and it takes less than a second to refocus from its closest focusing point to infinity at a 500mm focal length. I did wish there were a focal length range limiting switch that would limit the zoom range from infinity to about 75–100 feet. When I was shooting a surfing contest, if I got the autofocus point off the surfer, the lens would run through its zoom range. It wasn’t the speed of refocusing that was the problem, it was the difficulty of finding the subject again when the focus was less than 100 feet and the focal length was 500mm.

I did all of my testing on a Nikon D2x, so my effective focal lengths were 75–750mm. I felt a little out of place with my “little” Sigma lens standing among the other pro photographers with 600mm f/4 lenses on their full-frame Nikons and Canons. But I was getting tighter shots than they could.

For photographers using APS-C sensor cameras like me, Sigma includes an 86mm step-down ring for attaching filters. You are cautioned not to attach a polarizing filter to this step-down ring, but I’m not sure why since the front element doesn’t rotate during focusing or zooming, and you don’t need the petal-type lens hood that comes with the lens with a polarizing filter. The instructions say you may not be able to remove the filter from the lens.

For film or full frame sensor users, the filter diameter is 95mm. Yes, this is a big lens in all respects. It weighs in at a little over four lbs. At 50mm the lens is 8.5 inches long while at 500mm it is 12 inches. It is not the “all-in-one” lens to carry around all day that you would hope for with this perfect range of focal lengths, and a built-in optical stabilizer. But depending on the strength of your neck or shoulders, it is certainly possible to carry and hand hold the 50–500mm to shoot birds (although I used a wonderful Induro GHB2 gimbal mount), surfing and off-road racing (I used an Induro tripod and ballhead for both).

I did do a fair amount of nature shooting handheld, and the optical stabilizer is quite effective. Images were consistently sharp at 1/125 at the 500mm (750mm equivalent) focal length. Below 1/125 the percentages fell rapidly. The OS system, while effective, takes about a second to stabilize, and the image jumps up a bit in the frame, which required composing and then refocusing when shooting close-ups. A switch on the lens allows you to turn off the OS system, set it for horizontal and vertical-axis autofocus (Mode 1) or horizontal axis autofocus (Mode 2) to control only vertical shake.

Above the OS system switch is another switch to turn the autofocus system on or off. Down the barrel from these is a switch to lock the lens at its 50mm setting for carrying, although I never noticed any lens creep when I was carrying it. I actually found the focus and zoom rings to be a little stiffer than usual, and that they both turn in the opposite direction than the comparable rings on Nikon lenses. This continues to bug me!

I did some of the handheld shooting to test the close-focusing capability of the lens. Maximum magnification comes at the 200mm focal length and is 1:3.1, with a focusing distance of about two feet. I was impressed. Image quality at this magnification was impressive also.

Optical quality throughout the focal lengths and apertures is very good to excellent. Quality is generally excellent at all times in the center of the image, with some loss of sharpness and hints of color fringing at the edges of the image at the longer focal lengths. I suspect that photographers using this lens with full-frame digital SLRs would see more color fringing and some additional softness at the edge of the image than I saw with the D2x.

While the Sigma 50–500mm may not be the ultimate “all-in-one” lens for travelers to carry around all day, it is an excellent “all-in-one” choice for outdoor sports photographers, bird photographers and nature photographers with a photo backpack. For the latter group, close focusing with very good image quality is an added bonus. With its 10X zoom ratio out to 500mm, it is the latest in Sigma’s “most something in its class” lens releases.

Street price of the Sigma 50-500mm is about $1600. This includes a padded fabric case with shoulder strap, removable tripod collar, lens hood, front and rear caps, and 95–86mm step-down filter ring.  More information is available from www.sigmaphoto.com.

Stan Sholik is a commercial photographer with 30 years of studio and location experience. His specialty is still life photography for food, jewelry, medical and high-tech clients.