Laowa 7.5mm F2.0 lens test

Overview

• I just received the Laowa 7.5mm F2.0 lens (ordered it directly from Laowa via web-preorder).
• I did a small test to check the lens sharpness at different apertures. Initially I took pictures of a newspaper page at different apertures:

• The problem was that to cover the complete frame with the newspaper page I had to place the camera at a distance of 24cm from the newspaper page. But like this, at F2 the depth of field is so shallow that the image regions out of the centre are blurred due to lack of depth of field.
• So I did a different test, taking shots of the view from the window of a building. The closest parts of the scene were about 6-7 metres from the camera (the first lamppost from the left and the tree in tht bottom centre). Even at F2, all parts of the image would be in focus (with the bottom right better in focus than the bottom left at the largest aperture, because the bottom left was closer to the camera). The camera was on a tripod:

Test setup

• Olympus E-M1 Mark II (20 MP) with Laowa 7.5mm F2.0 lens mounted on a tripod.
• The lens was manually focused in the centre of the image.
  
• I triggered the camera with a smartphone and the Oly app to avoid camera shake.
• All images are out of camera JPEGs (auto WE, natural mode, ISO 200). No processing applied.
• Not knowing what lens was being used, the camera didn't apply any in-camera corrections (geometric distortion, vignetting, chromatic aberrations). 
• That means that when processing the RAW image, it should be possible to correct distortions, vignetting and aberrations.

Centre sharpness

Bottom corner, left

Bottom corner, right

High resolution sample images

F2	F2.8	F4	F5.6
F8	F11	F16	F22

Conclusion

• Sharpness
• At F2 the centre has almost the maximum sharpness. Sharpness in the centre improves at bit until F4-F5.6, but F2 is already sharp in the centre.
• The corners are sharp at F4 and sharpest at F5.6.
• In the unprocessed image there is visible vignetting until F4-F5.6. 
• Chromatic aberrations are visible, mostly in the corners, at all apertures. These are easy to remove this when processing the RAW file: