Even though we ARE Nikon lovers,we are NOT affiliated with Nikon Corp. in any way.

English German French

Sign up Login
Home Forums Articles Galleries Recent Photos Contest Help Search News Workshops Shop Upgrade Membership Recommended
members
All members Wiki Contests Vouchers Apps Newsletter THE NIKONIAN™ Magazines Podcasts Fundraising

Aperture variation from lens rotation.

geezerhood

US
4 posts

Click to send email to this author Click to send private message to this author
geezerhood Registered since 28th Mar 2014
Fri 28-Mar-14 02:36 PM | edited Fri 28-Mar-14 04:12 PM by geezerhood

Hello from a first time poster here at Nikonians, long time photographer (professionally since 1972), Long time Nikon owner (Fist one was an F2 purchased in 1975, Currently own a D800e.)

This may be a well known issue but I have never noticed it before today.

I was not able to find any reference to this in a search both on this site and the web, but you should know that Google and I don't really get along.....

Anyway, here is the problem I just discovered. Due to the slight play in the locking pin on the Nikon bayonet mount the lenses are allowed to shift slightly in either direction, clockwise or counterclockwise. This shifting when pushed to the maximum counterclockwise direction as viewed from the front of the lens allows the aperture setting to open up further than what you have set. Depending on how tightly the individual lens being used locks up, this can produce a moderate to significant shift in the position of the aperture.

I tested several lenses and they all had some shift in the aperture position. The least amount was found in current production Nikon brand. My Tamron 70-200 f/2.8 had significantly more shift than the Nikon brand lenses, about half a stop, and when I added in a Kenko 1.4x DGX TC the error increased to almost a full stop. Not really surprising since a second locking setup was added, essentially doubling the problem.

All lenses and the camera are as new with zero signs of wear on the mounting surfaces or locking pin. Movement is evident at every aperture setting with every lens I have on hand to try, when the lens is rotated in the mount in the locked position, other than fully open of course.

Mechanically I can see how to get rid of the play, add more material to the left side of the locking slot on the lens mount when viewed from the rear at 12:00 ( counterclockwise side). This would eliminate the counterclockwise movement and give constant, accurate aperture indexing, but HOW to do that properly is the question. I have some ideas of my own but would like to hear your thoughts.

Though I am pretty sure I am not the first person to ever observe this, I am still amazed I never noticed this before in some 39 years of shooting Nikon gear. Any advice towards fixing this? Now that I am aware of the issue, it is going to BUG me until I get it fixed. I don't like the idea of having to remember to rotate my lens counterclockwise before every exposure to be sure I am getting the right aperture setting.


Subject
ID
Reply message RE: Aperture variation from lens rotation.
1
Reply message RE: Aperture variation from lens rotation.
2
     Reply message RE: Aperture variation from lens rotation.
3
          Reply message RE: Aperture variation from lens rotation.
4
Reply message RE: Aperture variation from lens rotation.
5
Reply message RE: Aperture variation from lens rotation.
6
     Reply message RE: Aperture variation from lens rotation.
7
          Reply message RE: Aperture variation from lens rotation.
8
          Reply message RE: Aperture variation from lens rotation.
10
          Reply message RE: Aperture variation from lens rotation.
9

G