DigitalCameraReview.com
Sigma 18-35mm f/1.8 Lens Hands-On First Look Preview
by Laura Hicks -  5/23/2013

The announcement of the Sigma 18-35mm f1.8 lens stirred up quite a bit of dust. It was amazing to watch the initial reaction to this lens as there was a huge response from our press release alone. Lucky for us, Sigma sent a pre-production unit to preview. Unfortunately we are unable to post any images from our testing of this lens. But no worries, we have written a detailed account of its design and performance.

*Note: The 18-35mm f/1.8 lens shown above is a pre-production unit. The information and critiques we have of this lens are based on it's current configuration as it was sent to us. Sigma can and may choose to make changes with the lens before it is released to the general public.

Overview
The Sigma 18-35mm lens is one solid piece of equipment. Immediately I was able to notice that this lens is well built and created for years of use. The lens measures 3.1in x 4.8in. and weighs 28.6oz. This outweighs the Canon T5i that it was attached to by almost 8oz. The lens has a smooth outer surface with two rubberized rings: one near the mount for zoom and one near the end of the lens for focus. On the side of the lens sits a AF/MF switch. The 18-35mm lens is constructed of a combination of metal and Sigma's own Thermally Stable Composite -- Sigma means business with this lens. If there was ever a question of professional photographers using APS-C cameras, Sigma has an answer for that...and it's a resounding yes! Although Sigma has not released a price for this lens, we are guessing it will not come cheap--especially after holding it in our hands. This lens was not designed for the faint of heart or wallet. 

The 18-35mm lens is available in 3 mounts: Sigma, Canon and Nikon. The lens has been designed for APS-C cameras. The unit I received was designed for the Canon mount. I used it with the Canon Rebel T5i. 

Image Quality
Sadly, not being able to share the images produced by the Sigma 18-35mm lens is a huge bummer for me -- as this lens, in its current state, produces some amazingly sharp images. As soon as I am able to, I will release my images taken with this lens. Until then, I will describe in detail my testing. Most of my testing was done outdoors, however I did photograph indoors as well. I tested the lens through all apertures from f/1.8 to f/16. F/16 is the minimum aperture the lens will allow. I was very happy with the image sharpness throughout the entirety of the range. The was even tack sharp even at f/1.8. One of my favorite pictures I took is of my son. It was a close up of his face so I could get an idea of how sharp the image would be during a portrait session. My son got bored (as usual) and started to move around and act silly. The camera was set to f/1.8 at this time. I was able to produce a very, very sharp image (I only snapped one image during this time before I told him to be still so the testing could go faster). We finished up the rest of the testing. I didn't even realize how great the shot was until I pulled it up on my large 27-inch computer monitor.

After several round of indoor and outdoor testing throughout the entire aperture range I feel confidant in stating that this lens produces a consistently sharp image from edge to edge. I did not notice any vignetting with the lens. 

In Use
In use, the lens is a hefty piece of glass. It weighs more than the Canon T5i it was married to during our testing. The weight on the lens does make the camera/lens combo a bit lopsided. Other than that, the lens was easy to use. Because the zoom function is internal there is no telescoping of the barrel. The AF is fast, consistant and silent due to the Ultrasonic Motor. Sigma has even included a petal-type lens hood--a trend that is becoming less common than in the past. The lens features 17 elements in 12 groups. It has 5 SLD elements and 4 glassmold aspherical elements. The 18-35mm lens has 9 rounded diaphragm blades. This should, in theory, allow for a smooth bokeh effect in the defocus areas of an image. In reality, though I found the bokeh effect to have a mixed bag of tricks. In some of the areas it seemed smooth, while other times it seemed a bit angular, almost like a soft octagon shape versus a smooth circle. But remember that I am using a pre-production unit and this may change with the final version of the lens.

Conclusion
There are only a few concerns I have about this lens at the moment. First, the lens does not come with image stabilization. This could prove to be a deal breaker for some. I am actually surprised by this. The size and weight of this lens makes most APS-C sized cameras a little too lens heavy, requiring a steady hand. An IS system would make hand holding the camera/lens combo just a bit easier. Not having image stabilization would make me guess that the price point is a bit lower than my original estimation. My second concern with the lens is the mixed bokeh effect. As of right now, the bokeh is not near as smooth or consistent as my other Sigma lenses I own for my Nikon gear. My hope is that this will be refined before the final release of this lens. My final concern about this lens is the price. As of right now we have no idea what price Sigma will choose to attach to this lens -- and that worries me a little. On one hand, they have the market cornered. Neither Canon nor Nikon has an identical lens, therefore this would suggest they can pretty much price it however they want. On the other hand, if Sigma wants to rise above the competition they need to think like a consumer. Why would a customer choose to purchase one lens over another? 1. It has to be optically better than similar lenses, 2. It has to have features that other lenses don't have, and/or 3. It needs to be given a price point that is better than the competition. 

It's clear that Sigma is making a great effort to increase their brand recognition and improve their standings in the professional photographers' arena. And I think they are doing a good job. Their newest lenses look classy and professional. They are well made and have great appeal across a broad spectrum of the consumer base. But in order to really maximize on this branding campaign, Sigma will need to get this lens in the hands of a lot of working professionals. The only way that can happen is if they price the lens to appeal to a wide range of photographers. Gaining broad appeal with this lens will lead to a long-term, committed customer base that fills their camera bags with Sigma's products. A committed customer base will undoubtedly increase their brand loyality and, in turn, their profit margin. 

I can easily see this lens being the best friend to many working professionals and a lot of enthusiasts, too. It could, without hesitation, be the go-to lens for portrait and wedding photographers across the globe. The Sigma 18-35mm f/1.8 is a rock star, no doubt!