Tokina offers the AT-X Pro 24-70mm f2.8 FX from 2015 for around 900 EUR. It has no image stabilization.

We can clearly see that the Nikon 24-70mm f/2.8E VR shows decreased performance at 50mm when compared to wider focal lengths – its center performance is now noticeably weaker wide open. It also shows signs of “wavy” (sombrero) field curvature at f/2.8. Stopped down to f/5.6, however, the lens continues to impress with its performance across the frame. The acutance profile below shows the sharpness profile of the three lenses at their longest focal length and at f/2.8. Closing down the apertures increases sharpness to f/5.6-8, whereas after at f/11, all three begin to exhibit some diffraction and score below 70% acutance.

Image Quality

There is no shortage of 24-70mm f/2.8 lenses to compare the Sigma Art option to and that creates a decision-making challenge.

I see the Nikon performing better in the periphery at 24mm and the Sigma turns in slightly better 70mm results. Autofocus is very fast and whisper-quiet, thanks to an upgraded ultrasonic drive system that has a third more torque than in Sigma’s previous 24-70mm lens. The optical stabilizer gave a 4-stop benefit in our tests, matching the performance of the Nikon lens’s VR system but losing out to Tamron’s 5-stop stabilizer. As we’ve mentioned, the Canon lens doesn’t have a stabilizer. Lateral CA shows as color fringing along lines of strong contrast running tangential (meridional, right angles to radii) with the mid and especially the periphery of the image circle showing the greatest amount as this is where the greatest difference in the magnification of wavelengths exists.The older Nikon 24-70mm f/2.8G is not much better, showing similar results, although its pincushion distortion at longer focal lengths is less pronounced. The Tamron's VC (Vibration Control) is rated one stop higher than the Sigma's OS (5 stops vs. 4) and the Tamron has a modestly lower price tag at review time.