Found in Asahi Optical Industries (Pentax) lenses!
column
lens
![](http://vintageshopjapan.com/wp-content/uploads/2023/01/ai-11.png)
at first
I’m sorry
Because we can’t speak english
I am using DeepL translate, so it may be a strange sentence,
but I would like you to understand
Thank you
This time I wrote about a discovery I made with a manual focus lens from Asahi Kogaku Kogyo (Pentax).
We will refer to the lenses currently on sale at our vintage shop Japan Inc.
Asahi smc PENTAX-M 28mm f/2.8
![](http://vintageshopjapan.com/jp/wp-content/uploads/2023/01/1-348x360.png)
Click here to see the column of cleaning work
PENTAX smc PENTAX-A 50mm f/2
![](http://vintageshopjapan.com/jp/wp-content/uploads/2023/01/4-407x360.png)
Click here to see the column of cleaning work
One thing I noticed is that both lenses have a hemispherical object on the aperture display.
They are white or yellow in color and look like some kind of marker.
I have been trying to find out what the role of this part is.
![](http://vintageshopjapan.com/jp/wp-content/uploads/2023/01/2-1.png)
![](http://vintageshopjapan.com/jp/wp-content/uploads/2023/01/5-6-247x360.jpg)
I thought it was an alignment mark for attaching to the camera mount, but it was not because there were markings on the lens mount.
I have done a lot of research and have not found an answer.
I am still unable to understand it at this point, so I will investigate further.
I think it’s a functionally unimportant part (laughs)
So stay tuned for my next column!
In addition to the lenses introduced this time, we also sell vintage cameras and lenses,
so please see the URL below.
Cameras & Lenses
Animation Goods
Acoustics and others
Vintage Shop Japan Inc. Official Website
Official website (English) URL
Official website (Japanese) URL
facebook URL
Instagram URL
Pinterest URL
Writer Takashi Okumura
#asahipentax
#filmcameralens
#vintageshopjapan