In Part I, I discussed the reasons for doing this test and showed tight crops from the images. In Part II, I showed full images shot at F/2.8. In this part, I'll show the closeup images at the widest aperture of each lens, some of these images will have already been seen in Part I, other images will be new. In theory, wide open should show the best bokah for each lens, however, that may not be the optimum sharpness for a given lens. For most lenses, optimum sharpness is achieved when stopping down two or three stops from wide open.
Methodology. I used my Fujifilm XT-2 camera. At the time of writing, the XT-2 is the highest resolution (24MP) APS-C camera made by Fujifilm. In no way, shape, or form is this super accurate testing. There are no lens resolution test charts, no brick walls, nothing like that. Just my spouse (semi tolerant), some lights behind her to create bokah, and a flash in front of her. Images were imported into Lightroom for cropping and exported. No other correction was done.
The slowest lenses tested have an aperture of F/2.8, and since no lens is at it's best wide open, I also tested at F/4.0. Lenses that were faster were also test at lower F stops so the shape of the bokah was viewed. Some tested lenses have as few as seven aperture blades, nine was typical, one has 12 blades. The 12 bladed aperture provided beautiful round bokah at all settings.
|Description||Aperture Blades||No. Elements|
|Fujifilm XF16-55mm F/2.8 R LM WR at 55mm||9 (rounded)||17|
|Fujifilm XF50-140mm F/2.8 R LM OIS WR at 50mm||7 (rounded)||23|
|Fujifilm XF56mm F/1.2 R||7 (rounded)||11|
|Fujifilm XF60mm F/2.5 R Macro||9 (rounded)||10|
|Helios 44-2 58mm F/2||8 (rounded)||6|
|Nikkor 50mm F/1.4 (pre AI)||7||7|
|Nikkor 50mm F/1.4 (pre AI) Turbo II - Effective F/1.0||7||7+4|
|Nikkor 55mm F/2.8 Micro (pre AI)||7||6|
|Nikkor 85mm F/1.8D||9||6|
|Nikkor 85mm F/1.8D Turbo II - Effective F/1.3||9||6+4|
|Zeiss Jena Tessar 50mm F/2.8||12 (rounded)||4|
These images are all shot at the widest aperture of each lens.
Fujifilm XF16-55mm F/2.8 R LM WR 55mm at F/2.8
Fujifilm XF50-140mm F/2.8 R LM OIS WR 50mm at F/2.8
Fujifilm XF56mm F/1.2 R at f/1.2
Fujifilm XF60mm F/2.5 R Macro at f/2.5
Helios 44-2 58mm f/2 at f/2.0
Nikkor 50mm F/1.4 (pre AI) at F/1.4
Nikkor 50mm F/1.4 (pre AI) Turbo II at F/1.4 - effective F/1.0
Nikkor 55mm F/2.8 Micro (pre AI) at F/2.8
Nikkor 85mm F/1.8D at F/2.8 (FF equiv. field of view - 127mm)
Nikkor 85mm F/1.8D Turbo II at F/1.8 - effective F/1.3
Zeiss Jena Tessar 50mm F/2.8 at F/2.8
Mazimum Aperture Conclusions:
The Fujifilm 16-55mm shows some onion ring bokah, not strong, but not clean.
The Fujifilm 50-140mm zoom shows some oblong bokah.
The Fujifilm 56mm bokah shows slight onion rings and has an oblong appearance around the edges, otherwise it's ok.
The Fujifilm 60mm bokah is very clean when the lens is wide open, bokah circles are round and clear.
The Helios bokah is oblong everwhere, getting progressively worse further from the center of the image.
The Nikkor 50/1.4 bokah looks clean everywhere, nice and round. Adding the Lens Turbo to the lens turns the bokah into footballs.
The Nikkor 55/2.8 bokah also looks clean in the center and moves to oblong towards the edges of the frame.
The Nikkor 85/1.8 bokah is very even throughout the frame, nice circles. Adding the Lens Turbo changes the bokah circles into footballs towards the edges.
The Jena bokah has a hot spot in it's center, giving a slight 3D appearance to it. The Jena also shows some oblong shaped bokah towards the edges.