Sigma's First Digital ONLY Macro Lens

The 17-70mm f2.8-4.5 DC Macro AF (Auto Focus) is Sigma's first digital only macro lens. It is also the industry's FIRST digital macro zoom, making this lens the standard that other manufacturers will have to meet or beat to keep their product mixes up to date.

As a Nikon user and owner, I had the opportunity to use this lens on military provided D1X and D2X camera bodies. With Nikon's 1.5x conversion factor, this lens is the equivalent of a 29-119 mm lens on a film SLR body.

What is especially nice about this lens is its high speed and ability to magnify. With a quite modest price, this is also a very cost effective lens for users of digital camera bodies.

Below are my observations when using it on the D1X and D2X camera bodies routinely found in U.S. military combat camera sections.

LENS CONSTRUCTION:

At first glance, the lens appears to be quite well made. Initially, the lens feels light in your hands and for the class it occupies. By contrast, the nearest competing Nikon lens, the 17-55 mm f2.8, is more than a half pound heavier. Like other Sigma pro line lenses, this one features the company's matte black finish. The focusing and zoom rings are made of a ribbed, rubber type material. These rings provide a sure gripping surface.
The zoom collar is damped quite well, but the focusing ring reminds me of one of the main annoyances I have with another Sigma lens I own (the 28-70 f2.8) due to the scratchy noise it makes when focused manually. This lens also has that same somewhat annoying trait.

The lens barrel is quite well marked with subject distance, zoom and magnification scales. There is a zoom lock at 17 mm, but the drag in zoom action during manual focusing will probably mean that you'll rarely use it. I know that I don't and don't plan to in the future.

For Non-Nikon users/owners: Sigma also manufactures this lens for Canon, Pentax, their own Sigma bodies and the soon to be departed Konica Minolta digital camera bodies.

SPECIFICATIONS:

Focal length: 17-70 mm (convert to film equivalent based on which camera you use).

Lens Construction: 15 lens elements in 12 groups.

Focusing: Auto Focus or manual. The focus ring turns 50 degrees counterclockwise. The Zoom ring turns 60 degrees clockwise. The focal lengths are marked on the lens barrel at 17, 24, 35, 50 and 70mm.

Diagonal Viewing angle: 72-20 degrees.

Weight: 1.01 lbs.

Filter Size: 72 mm

Accessories Included: Lens hood and softcase.

In Use Observations:

This lens will probably be criticized by Nikon purists and retailers who in the past, have blamed Sigma for lack of build quality or softness in certain lens elements. I have not found that to be the case at all. As I mentioned earlier, this lens is ruggedly built despite its reasonable street price. That element is further enhanced should you compare it to a Nikon lens in the same broad category. Nikon lenses are almost always much higher in cost.

Throughout most of the focal range of this lens, I have found it to be incredibly sharp and with excellent emphasis in terms of contrast. The universal closest focusing distance for macro photography is a rather scant 7 inches. This despite it's film equivalent at max zoom of 119 mm. The magnification ratio at 17 mm and 7 inches distance is 1:4.6 and at 70 mm, it is 1.19. There is almost no vignetting at 35 mm.

There is one drawback to the high performance offered by this lens and it is the fact that when zoomed to 70mm, the lens sticks 5 inches off the lens mount. As a result, this lens is certainly not very compact in the wide to short zoom category. Then again, since this IS the only lens of its type and focal length currently available, you're not going to be able to find a competitor. It should also be remembered that given its variable aperture, starting at f2.8 and ending at f4, this is a fast lens and design engineering being what it is, there will be trade-offs.

FINAL THOUGHTS:

I do not own this lens and the one I use is owned by the U.S. Army. But having used it for close in work, including detail work, I have found it to be a very commendable performer. I am giving very serious thought to purchasing this lens when I return home from my duty location. The speed, sharpness, contrast capture capabilities and street price make this lens a great overall bargain. Using it on a Nikon digital body has been fairly effortless and I am sure it will perform just as well on other brand bodies, too.

I recommend this lens regardless of which camera system you are using.