Sigma APO 50–150mm F2.8 EX DC OS HSM: An APS C Warrior

 
Sigma APO 50–150mm F2.8 EX DC OS HSM

Sigma APO 50–150mm F2.8 EX DC OS HSM

Ambarin Afsar discovers what the Sigma APO 50–150mm F2.8 EX DC OS HSM has in store for APS-C camera users.

Usually, when I receive a telephoto zoom for testing, I feel really excited about the review. This is because telephoto zooms offer endless possibilities—from portraits to nature and wildlife. When I found out that I was testing Sigma’s stabilised version of the 50–150mm f/2.8 meant for APS-C sensors, I was even more thrilled. What would this lens offer that the Nikon and Canon stalwarts, the 70–200mm lenses didn’t already?

Features
The Sigma 50–150mm f/2.8 EX DC OS HSM offers an effective focal length of 75–225mm on an APS-C body. The most significant feature about the lens is that it is made specifically for cropped sensor users.

This can be both good and bad. It is good because this means that the lens is lighter and cheaper. But, it is also bad because if you are planning to upgrade to a full frame body soon, then it makes no sense investing in this, considering the 70–200mm full frame options already made available by Canon and Nikon. However, D800 users need not worry so much since the camera gives a respectable output of 16MP in the DX crop mode.

The other major feature of this lens is its constant fast aperture of f/2.8 throughout the focal range. This extremely useful for low light shooting and opens up a world of opportunities. Additionally, the lens features a 9-bladed diaphragm unit that offers soft, pleasing bokeh, but we have seen far more pleasing bokeh in proprietary lenses.

For this lens, Sigma has completely revised its optical design of the previous 50–150mm f/2.8 lens and has included optical stabilisation in the 50–150mm f/2.8 OS that gives a 4-stop advantage.

The lens features 21 elements in 15 groups and six SLD glass elements, to compensate for chromatic aberrations. The lens also has a Super Multi-Layer Coating to help reduce flare and ensure sharp images at wide apertures.

Handling
The 50–150mm f/2.8 OS comes along with a tripod collar and a tulip-shaped hood that has a ribbed ring for better grip. The lens feels solid, given its metal and polycarbonate plastic construction. However, oddly enough, the lens is not weathersealed, which seems like a major oversight on Sigma’s part, considering its application.

But, while it is slightly lighter than the Nikon and Canon 70–20mm lenses, the lens is not as light as we expected it to be.

The zoom and focusing rings are rubberised and twist easily. The lens also has a DOF scale, right next to which are situated the AF-MF and OS switches.

Performance
The lens, while not as sharp as the Canon and Nikon 70–200mm versions, offers decent sharpness across the zoom range and across apertures. The image quality is good and edge sharpness and detail meet expectations. I did not find too many instances of fringing or flare. The latter occurs only when a bright subject is shining directly into the lens.

Shots taken in strong backlighting where the light source was outside the frame, showed very little loss of contrast. Overall, colour fidelity was well maintained. Also, while this is not a macro lens, I was able to get quite close to subjects like dragonflies when shooting at the telephoto end, due to the close focusing distance.

The AF was generally quite quick, except in certain low light situations, where it tended to hunt. There were a few instances of backfocusing as well, but it wasn’t something that was consistent. Besides, the lens allows manual override which is quite smooth and helpful in tricky situations.

Conclusion
Considering that Nikon and Canon have hiked the prices of their 70–200mm lens arsenal, this lens actually becomes a good buy at Rs. 73,500. If you are looking for a fast telephoto zoom that is optically stabilised, then this is definitely a good option for you. However, if you are willing to sacrifice stabilisation or f/2.8 aperture, both proprietary manufacturers have cheaper, sharper lenses that you can buy.

Shot at 150mm, in this situation the AF did a good job of locking on to the girl. Exposure: 1/3200sec at f/7.1 (ISO 800). Photograph/Ambarin Afsar

Shot at 150mm, in this situation the AF did a good job of locking on to the girl. Exposure: 1/3200sec at f/7.1 (ISO 800). Photograph/Ambarin Afsar

Final Ratings
Features
Fast aperture throughout the focal range, 4-stop IS advantage
17/20

Performance
Good optics, responsive AF, image quality could have been sharper
30/35

Build Quality
Solid, but no weatherproofing
20/25

Ergonomics
Focus override, DOF scale
13/15

Warranty & Support
Two-year warranty, limited service centres
2/5

OVERALL: 82%

Value For Money: 3/5

Who should buy it? TAPS-C enthusiasts who do not plan to migrate to full frame any time soon.

Why? The options available for full frame users offer far better image quality at fast apertures. Also, this lens will not be compatible with Canon full frame bodies.

Tags: Ambarin Afsar, Telephoto lens, Lens review, september 2012, sigma lens, Sigma APO 50–150mm F2.8 EX DC OS HSM