There's a lot of conversation on the internet about the sharpness from the 28mm f/1.8. I received mine yesterday and thought I'd take some sample pictures to review the sharpness at various apertures.

First, pictures of a building with a brick wall. The full scene picture is below:


2012_06_01_5578_upd by dthrog00, on Flickr

Now, 100% center crops, first at f/1.8



2012_06_01_5582_center by dthrog00, on Flickr

f/2


2012_06_01_5581_center by dthrog00, on Flickr

f/2.8


2012_06_01_5579_center by dthrog00, on Flickr

f/4


2012_06_01_5578_center by dthrog00, on Flickr

f/5.6


2012_06_01_5577_center by dthrog00, on Flickr

The f/1.8 shot is more soft than the others. The f/2 shot has sharpened up quite a bit with improved contrast. I would say the f/2 shots and beyond have acceptable sharpness even at 100%. But, if I post process the f/1.8 shot can I get to look as good as the f/2 (update levels and apply unsharpen mask amount 75%, radius 2, threshold 3)?


2012_06_01_5582_center_sharpened by dthrog00, on Flickr

In my opinion it is pretty close. But what about the mid-frame section of an APS-C camera with the lens wide open at f/1.8? The original shot is below:


2012_06_01_5564_resized by dthrog00, on Flickr

The 100% crop of the cat's face is below:


2012_06_01_5564_midframe by dthrog00, on Flickr

The shot as a whole looks ok, but there's no question the cats eye has a soft "haze" to it. I sharpened it (amount 75%, radius 2, threshold 3) below.


2012_06_01_5564_midframe_sharpened by dthrog00, on Flickr

Is it perfect? No. But, the haze from the cat's eye is gone. I think the picture as a whole looks ok. So far in real world conditions I see no reason why I should be reluctant to shoot at f/1.8 if I need the faster shutter speed, although f/2 would be preferred in most circumstances.

I think the new lens is great so far and am looking forward to shoot with it more.

Dave