Some good news for the format (including an 8,5 mm f/2.8)
25mm Samples
https://www.lenstip.com/2276-news-Kowa_Prominar_MFT_25_mm_f_1.8_T1.9_-_sample_images.html
Kowa Prominar 25mm review
https://www.ephotozine.com/article/kowa-prominar-25mm-f-1-8-mft-lens-review-32021
12mm F1.8 Kowa Prominar review
https://www.ephotozine.com/article/kowa-prominar-12mm-f-1-8-mft-lens-review-32027
8.5mm lens review
https://www.ephotozine.com/article/kowa-prominar-8-5mm-f-2-8-micro-four-thirds-review-32013
KOWA Cine Prominar 20mm, 25mm, 32mm, 40mm, 50mm, 75mm and 100mm Lens Test
The Kowa Prominar MFT 12mm f/1.8 is the weakest offering in the Kowa lineup. The pure MTFs are actually quite decent. The center is always sharp at the mainstream settings and the outer image region is relatively decent at f/1.8, good at f/2.8 and very good between f/4 and f/8. However, field curvature is a major issue at large apertures so in the real life the results are less convincing here - at least in our sample which wasn't really well centered. Typical for the three initial Prominar lenses, both the distortion as well as the lateral CAs are low which is good because image auto-correction isn't possible. The amount of vignetting is generally on the high side though.
Kowa lens has good optical performance. The image quality is decent at max. aperture but when stopping down it is about as good as it gets on the micro four thirds system. The low level of lateral chromatic aberrations contribute to the subjective quality perception. There's some vignetting at f/1.8 but not much beyond. Image distortions are also on the low side.
8.5mm
- Vignetting: “Average”
- Distortion: “Excellent”
- Resolution: “Above Average”
- Chromatic: “Average”
- Sun star: “Below Average”
- Coma: “Average”
To sum up each test item our ranking for this lens performance is “Average”.
http://m43lens.blogspot.tw/2014/09/kowa-prominar-85mm-f28-test-review.html
There are many things to make a lens dedicated for cinema. Here the tag is for the distortion I guess (which is quite good considering the focal).
Constant color and aperture between the same two lenses with low vignette and distortion is usually what Cinema lens are about but this is more or less a "hollywood standard" rather than a "true cinema look" experience because you only need to be good to do that. The purpose is to have same color reproduction, light and bokeh in the film and have lens that match almost perfectly for stereoscopic rig. Best filmmakers didn't really gave a damn about having only one set of prime lenses that reproduce exactly the same colors, distortion and vignetting. TV series on the opposite wants that.
I do wonder what is "cine" about these lenses? They are not uniform, FFocus threads are so-so, optics are so-so. Maybe the price (OTT for what you get) is what is in line with the cine tag?
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