Sony 28mm F2.0 vs. 35mm F2.8 - Sharpness Comparison
Marc Heijligers, 21-02-2016On this page you’ll find a detailed comparison between the sharpness of both lenses.
Summarized Results
The tables below show the summarized relative performance of both lenses. As you can see, the 35mm is sharper until f2.8, beyond that both lenses are approaching each other (with the exception of the tilted lens problem with the 35mm, resulting in more asymmetrical sharpness for the 35mm F2.8 lens at the left side of the frame).Test Conditions
Both lenses are tested on an A7RII.The first test is to judge the field sharpness of the lens. For this I use a bookshelf, which has a flat surface and a lot of books where the text on the book spines can used to test the subjective sharpness at a distance of 1.5 to 2m (not fully scientific, but sufficient to represent practical use cases for most of us). The camera is put on a tripod, where care is taken that the camera is perpendicular to the bookshelf (using the level indicator of the camera, visually checking the camera is in the middle, the bookshelf plates are symmetrical in the viewfinder, and double check with LensCal that the book spines are within the DoF range). The focus point for all photos is always in the centre (though other focus points have been checked for sanity, as well as multiple pictures to exclude focus differences). For lenses with different focal length, the camera is moved such that the composition of the scene remains the same in the viewfinder. Photos have been made with Steadyshot turned OFF, Silent Shooting turned ON, and a timer (but the differences are hardly visible with complementary settings in this specific setup). Pictures are taken in RAW, and processed in Lightroom with the Camera Neutral setting, and with Lens corrections enabled. For sanity, I’ve checked the difference between JPG, and RAW with corrections turned off, but the results are similar. Three regions are considered in the tests, one in the centre, one at the bottom-left, and one at the top-right. To investigate color fringing, tests have also been done closer to some books that have a high level of contrast.
The second test is to test the lens for sharpness at further distance. For this purpose I photographed a (boring cloudy) city scene from the balcony. This rules out the problem with the camera might not be absolutely perpendicular to the bookshelf. Furthermore, the larger distance increases the depth-of-field for distant objects, hence if there are internal or shifted lens elements, it also reveals unsharpness in those conditions. Also here three regions are considered the centre, the left, and the right side.
Detailed Comparison
Use the filter button below to select which cases you want to see and compare in detail (the buttons will limit the selection), and use the slider to compare the Sony 28mm F2.0 (on the left) and the Sony 35mm F2.8 (on the right).-
Bookshelf, Centre, Open Aperture (f2.0 and f2.8) - The 35mm lens is much sharper open. The 28mm lens shows purple fringing, and is a bit soft.
-
Bookshelf, Centre, f2.8 - At f2.8, the 28mm is a bit sharper, and has no purple color fringing.
-
Bookshelf, Centre, f5.6 - Both lenses are very sharp. The 28mm is a fraction sharper.
-
Bookshelf, Left Side, f.open (f2.0 and f2.8) - Both lenses are unsharp here. The 35mm lens has less sharp text (“National Geographics”), and a slight green fringing.
-
Bookshelf, Left Side, f2.8 - The 28mm lens improves to a decent sharpness. For the 35mm lens, it is unsharp, and has a slight green cast.
-
Bookshelf, Left Side, f5.6 - The 28mm lens is very sharp here, whereas the 35mm lens hardly improves from f2.8. This phenomenon is caused by a tilted internal lens element. An older version of this lens had a similar sharpness problem on the right side, and was sharp left.
-
Bookshelf, Right Side, f.open - The 28mm lens is hazy. The 35mm lens is decently sharp.
-
Bookshelf, Right Side, f2.8 - The 28mm lens is still hazy. The 35mm lens is decently sharp.
-
Bookshelf, Right Side, f5.6 - The 28mm lens is OK, but still worse than the 35mm lens.
-
City, Centre, f.open (f2.0 and f2.8) - The 35mm is sharper here. It is obvious that the 35mm lens is more “zoomed” in the same pixel crop than the 28mm. This is not te case with the bookshelf, as for each lens I reposition the camera so that the same composition is created. For a scene at infinity this is not possible.
-
City, Centre, f2.8 - Comparable sharpness for both.
-
City, Centre, f5.6 - Both are very sharp.
-
City, Left, f.open (f2.0 and f2.8) - The 35mm lens is definitely sharper here.
-
City, Left, f2.8 - The sharpness is about equal.
-
City, Left, f5.6 - Comparable sharpness.
-
City, Right, f.open (f2,0 and f2.8) - The 28mm lens is blurred here. The 35mm lens is decent.
-
City, Right, f2.8 - The results for the 28mm lens stays the same as with f2.0. The 35mm is decent, and better than the 28mm.
-
City, Right, f5.6 - Here the 28mm is reasonanle sharp, the 35mm lens sharper.
-
Bookshelf Left, Sony 28mm F2.0, f2.0 versus f5.6 - One can see the sharpness increases quite a lot.
-
Bookshelf Right, Sony 28mm F2.0, f2.0 versus f5.6 - Like on the left side, the sharpness increases a lot when stopping down this lens.
-
Bookshelf Left, Sony 35mm F2.8, f2.8 versus f5.6 - The sharpness hardly increases when stopping down.
-
Bookshelf Right, Sony 35mm F2.8, f2.8 versus f5.6 - The sharpness hardly increases when stopping down.