The Nikon 50mm f/1.4 AI Manual focus 1970s lens
50mm f/1.4 AI Portable normal lens.
Maximum aperture f/1.4 – Minimum aperture f/16.
Lens construction 7 elements in 6 groups.
Closest focusing distance 45 cm/1.48 ft.
No. of diaphragm blades 7
The no of diaphragm blades means, for example, the Nikon 50mm AI lens have heptagon-shaped bokeh effects and the Starburst in long exposure photography is gonna be 14 stars.
Filter/attachment size 52mm.
Weight Approximately 255 g/9.0 oz.
Manufactured from 1977-1981.
My son is using this lens with good performance on a Sony A7ll camera using lens adapter.
He is getting really good pictures when the lens is used wide open at f/1.4, much better than I could on my Nikon, I’m guessing it has something to when manual-focusing with focus peaking on the Sony camera that he has, that’s a good technology in the Sony A7ll, focus peaking works well with older manual-focus lenses on the Sony A7ll.
Pictures that my son took with Nikon 50mm 1.4 AI and Sony A7ll.
In my opinion, this lens is sharp just like any other Nikon 50mm 1.4 lenses when used wide open.
I have read online that this lens isn’t sharp and I think I know why some people are saying that this lens has twice the focusing rotation when focusing from closest focusing to the infinity than my Nikon 50mm 1.2 AI-S lens that I have, so it is twice as hard to get perfect focus, you think the lens is in focus, when it’s slightly off.
How to identify AI lens from AI-S lens.
The minimum aperture f/16 number on the lens have blue colour on AI lenses, on AI-S lenses the colour is orange.
Also on AI lenses the eight colour stripes on the silver ring with one black in the middle, the AI-S lenses have six colour stripes with one black in the middle.
long exposure Photography.
This lens can flare a little bit during long exposure photography, even on f/8, see on the (Crop image below) on the starburst, one star is much bigger than the others.
The images below are crop from the picture above.
My conclusions and recommendation.
Much easier to get good focus with Sony cameras that have focus peaking in live view when the lens is used wide open on maximum aperture f/1.4.
This lens flares a little bit and suffers from chromatic aberration on maximum aperture f/1.4.
Nikon 50mm 1.4 AI lenses are usually cheap so that is good.
In my opinion, this lens is better than Nikon 50mm 1.8 pancake lenses.
It takes time to learn manual focusing on this lens.