Sigma 70-200 mm 2.8 lenses have been popular for a long time. And the latest version, the Sigma 70-200 mm 2.8 OS, will become even more popular. The combination of the focal length range at f/2.8 and the integrated image stabilization makes the Sigma 70-200 mm OS even more universal than the Sigma 70-200 lens without image stabilization. The field of view of 70-200 mm lenses is ideal for sports photography, portrait photography or wedding photography. Compared with the Canon 70-200 mm 2.8 and the Nikon 70-200 mm 2.8 , the Sigma 70-200 mm 2.8 OS is cheaper and lighter.
We are curious about the scores of the Sigma 70-200 mm OS in combination with the Sigma SD1 Merrill camera. The Sigma SD1 Merrill is provided with a Foveon sensor, that works according to a different principle than the Bayer sensors from other cameras. This might result in higher resolution data for the Sigma 70-200 OS in this review.

Sigma 70-200 2.8 OS Construction and autofocus

The Sigma 70-200 mm OS lens has a very nice finish. Both the zoom ring and the focusing ring have exactly the right friction. The absence of slack gives a feeling of solidity. Already a few years ago Sigma switched to a different and improved coating of the housing. The previous coating looked nice, but was not as durable. This is now improved.
The Sigma 70-200 mm lens is lighter than its peers from Canon and Nikon. Which is very nice, since at the end of the day every ounce is one too many. The tripod socket is very convenient. It can quickly be removed while the lens is on the camera. Usually you have remove the lens from the camera body before you can remove the tripod collar.
What is also very nice to this lens, is that it comes with a durable pouch and two hoods. One hood is for use on a camera with an APS-C sensor and a larger hood for use on a camera with a full frame sensor.
The AF of the Sigma 70-200 mm OS is powered by an internal focus (HSM) motor. The extremely short focusing time of a Canon 5D MK3 with Canon 70-200 2.8 II is not reached by the Sigma 70-200 mm 2.8 OS. The combination Sigma SD1 Merrill + Sigma 70-200 mm 2.8 OS achieves usually sufficiently fast focusing. In low light or low contrast AF system sometimes this combination sometimes hunts.
In this review we did not test the image-stabilization of the Sigma 70-200 mm 2.8 lens. Our reviews of this lens with Canon cameras show that the Sigma 70-200 mm 2.8 OS features an effective image stabilization.

Sigma 70-200 2.8 OS Vignetting

Here you see the Imatest results fir vignetting in jpg files from the Sigma SD1 + Sigma 70-200 mm OS. Vignetting from the Sigma 70-200 mm OS, expressed in stops, is already low with the aperture wide open. After stopping down 1 stop, vignetting is even very low. In short, beautiful vignetting values! This applies to both RAW and jpg files.

Sigma 70-200 2.8 OS Distortion

The graph for the distortion in jpg files created with the Sigma 70-200 mm OS 2.8 + Sigma Sd1 Merrill looks as usual for a telephoto zoom lens. In the middle of the zoom range, the lens shows very low distortion and in the extreme zoom positions the distortion is low. Remember that this type of lenses is usually used in forms of photography where distortion rarely or never will be visible. Examples include sports photography and model photography.

Flare

The Sigma lens has a complex design and contains 22 lenses in 17 groups. A design with a large amount of lenses increases the vulnerability towards internal reflections and thus there is a larger probability for visual glare and ghosting in bright light situations. This image is shot at f/5.0The supplied lens hood is great, but you will have to be careful for backlight. Incidentally, this is what we found in the Canon 70-200 mm 2.8 IS II.

Sigma 70-200 2.8 OS Resolution

The resolution expressed in lines / height sensor exhibits in the center at 70 and 135 mm very nice values. Aperture is therefore not necessary. At 90 mm and 200 mm, the center sharpness at f/5.6 just a little better than at f/2.8. The corner sharpness is very good with the exception of 200 mm. That is the difference between the center and the corners somewhat larger.The resolution, expressed in LW/PH, exhibits in the center at a focal length of 70 and 135 mm very nice values. At a focal length of 90 mm or 200 mm, the center sharpness is at f/5.6 just a little better than at f/2.8. The corner sharpness is very nice with it, except at 200 mm. That is the difference between the center and the corners somewhat larger. Put your Sigma 70-200 mm 2.8 on a Canon 60D with 18 MP image sensor, or a Canon 5D MK2 with 22 MP, it appears that the Sigma SD1 overall the highest resolution displays!
The quality of the Sigma Foveon compared to a Bayer sensor does not even fully legal in standard black and white resolution measurements we have performed. A 16 megapixel camera with a Bayer sensor has only 4 megapixels that register the color red or blue. The Foveon sensor of the Sigma SD1 has 16 megapixels which each register the colors red, green and blue. It is possible that the resolution of the Sigma SD1 Merrill, using a red-white test card or a blue-white test card, will outperform cameras with a Bayer sensor.
The high resolution of a lens in combination with the Sigma SD1 is best reflected by using the Sigma SD1 Merrill RAW files. Because these files cannot be read by Photoshop or Lightroom, you are forced to use Sigma’s included free (and easy to learn) RAW software.

Bokeh

A 70-200 mm 2.8 lens use sometimes to get good background blur. The combination of high brightness and a longer focal length which are important conditions. What we see is a beautiful bokeh, the blurred circles show little or no rings. The result is a nice quiet appear blurred background.

Sigma 70-200 2.8 OS Chromatic aberration

The chromatic aberration of the Sigma 70-200 mm 2.8 OS remains low at all apertures. Correction of chromatic aberraion with photo-editing software will therefore seldom or never be needed.

Conclusion Sigma 70-200mm f/2.8 EX DG OS HSM APO review

Pros

• HoogHigh resolution in the center from f/2.8, with the exception of 200 mm
• Fairly small difference between centrumscherepte and corner sharpness at most focal lengths
• Beautiful woolly display onscherrpe parties
• Very low distortion
• Slight vignetting
• Low chromatic aberration
• relatively light in weight,
• Very good price / quality ratio

Cons

• Autofocus is not very fast
• Sensitive to light
• Not waterproof

The Sigma 70-200 mm OS 2.8 is a very good combination with the Sigma SD1 Merrill camera. In terms of resolution / sharpness, this lens to better advantage on a Sigma SD1 Merrill than with the Canon 60D or the Canon 5D MK2. The Sigma 70-200 mm 2.8 OS on a Sigma SD1 Merrill is an attractive lens, especially when you consider that the Sigma 70-200 mm 2.8 OS lot cheaper.