This is the second in a series of entries about my newest lens, the Tamron SP AF 17-50mm 2.8 XR Di II VC LD Asp IF. Just like in the last post, these images are from Saturday. I haven’t gone out today, weather was rainy throughout, and the only images that I have made, were some reproductions of old photographies.
The first image is of a yellow sign that I found on a garden fence. It asks for caution when digging, because of a power cable. I liked color, texture and the crumpled look. The image has been treated with a healthy dose of Topaz Detail, strongly emphasizing local contrast. This is f5.6 at 50mm.
The next image is from the same place as the Image of the Day. It’s a former restaurant/café at the foot of a tower where once pellets were cast. It is on the northern shore of Wörthersee, the most prominent of Carinthia’s many lakes.
On the left side you have the image just as it came out of the camera, on the right side is my version from RAW, where I have tried to extract as much detail as possible, and to present the late autumn afternoon colors as radiating as they were. Additionally I have tried to correct the strong barrel distortion at 17mm with PTLens. I am not completely sure what the problem is, I strongly suppose PTLens mistakes this lens for its predecessor, the version without stabilization. In any case the correction is obviously wrong. It is quite OK at 17mm, there really is barrel distortion, but at 50mm PTLens tries to correct a pincushion distortion that is clearly not there. Maybe I should take my time and provide the necessary input for Tom to make the correction profile 🙂
The image was taken at f8. Other tests say that this lens’ sweet spot is at f5.6, this conforms to my own impression, but f8 is pretty good as well. Both thumbnails link to the full-size images. The JPEG right out of the camera is very sharp, my version builds upon that. I have corrected distortion, added saturation and sharpened the image, but otherwise I have left it pretty much as it was. Just see for yourself. I’d say I see some sharpness falloff in the farthest corners, not bad at all, but noticeable, even when not photographing charts.
This is again f8, this time at 50mm. In this case I have added local contrast with Topaz Detail, added some saturation and again sharpened the image. I have not applied any distortion correction. PTLens would have so, albeit grossly wrong. Actually this looks pretty good to me.
As regards sharpness, this image is razor sharp across the frame, and if you look at the big version of the Image of the Day, I’d be surprised if it were possible to get any more detail out of a 12 megapixel sensor, regardless of camera brand, regardless of lens. This is as good as it gets.
Well, here we are. So far we have looked at nominal conditions, i.e. sharpness at f8, an aperture that we are likely to use in typical landscape images. The result is good at 17mm and outright excellent at 50mm. This is also as expected. Zooms frequently show some weakness at their shortest focal length. In this case there is strong barrel distortion and a tiny bit of sharpness falloff in the far corners. The former can be corrected after the fact, the latter is not bad at all and unlikely to be a problem in real-world situations. We’ll have to make a further look into performance at f2.8 though. This will be the topic of another post.