I've just picked up a Canon-fit Sigma 50mm f/1.4 and thus far, I'm distinctly underwhelmed with it. But I'd appreciate some assistance with ascertaining whether it is me or the lens at fault here - or both of us.
IMy first task, as always, was to run it through a series of 'wall tests' where I set the camera up parallell to a wall, mounted on a tripod and triggered remotely and took a series of shots at various apertures to check for sharpness, distortion, etc.
However, the results were a little odd.
I shot at f/1.4, f/2.8, f/5.6, f/8 and f/11 and for the most part the sharpness and quality of the images were superb. Yet in a few the lens hadn't nailed the focus and in some others the images were a little soft and had some colour-fringing evident.
And while I was out in the garden doing the aforementioned test, I took a few pot-shots of the washing-line just to see what the lens was like in 'real world' terms at f/1.4. And there was CA absolutely everywhere. Anything from the focus point to the camera was fringed in purple and anything behind the focus point had a greeny/blue outline.
So finally I've set something up indoors. A silly little test where I've got the camera set up on a tripod, remotely triggered, and focused at a page of the newspaper - as seen below, if you click on the Spoiler button.
In said photo I'm focusing on the 'bl' of 'Wimbledon' and shooting at f/1.4, which at the target's distance of 18" ought to give me around 0.25" of DOF around the focal point. The image is unprocessed and merely cropped to the size seen above.
I know what I think, but what do you reckon?
IMy first task, as always, was to run it through a series of 'wall tests' where I set the camera up parallell to a wall, mounted on a tripod and triggered remotely and took a series of shots at various apertures to check for sharpness, distortion, etc.
However, the results were a little odd.
I shot at f/1.4, f/2.8, f/5.6, f/8 and f/11 and for the most part the sharpness and quality of the images were superb. Yet in a few the lens hadn't nailed the focus and in some others the images were a little soft and had some colour-fringing evident.
And while I was out in the garden doing the aforementioned test, I took a few pot-shots of the washing-line just to see what the lens was like in 'real world' terms at f/1.4. And there was CA absolutely everywhere. Anything from the focus point to the camera was fringed in purple and anything behind the focus point had a greeny/blue outline.
So finally I've set something up indoors. A silly little test where I've got the camera set up on a tripod, remotely triggered, and focused at a page of the newspaper - as seen below, if you click on the Spoiler button.
I know what I think, but what do you reckon?
