Nikkor 300mm f/4 AF-S

Posted: Sat Jul 17, 2010 3:31 pm

Hello,

This is a new lens for me, I have had it for awhile but finally had an opportunity to use it. I knew about the weak design of the foot/collar from a support standpoint and knew a replacement may or may not be needed. I found that Kirk has an outrageously priced replacement, are there any other alternatives aside from machining my own? Another issue is that when you loosen up the collar mounted on a tripod, the lens barrel does not rotate freely. Especially when comparing movement to my previously owned 70-200mm f/2.8 VRI which was smooth. Also, the "hood" does not stay firmly in place on the lens barrel when not in use. I found some small dimples which may offer resistance against the barrel to keep it in place. Perhaps they are worn out... I looked at boccaphoto for a replacement hood but came up empty, any ideas? While the first issue I am familiar with, I do not recall hearing/reading anything on the rotational issue, or the hood falling down when not in use.

I am tempted to remove the paint from the Nikon foot/ring to determine if this is solid stock Aluminum, or cheap pot metal Aluminum. If it is weldable, I will increase the structural support of the foot by adding a rib. If it is pot metal, I am considering using JB weld to afix the rib. Either way it would cost me far less that the "replacement" foot/collar. The lens is not under warranty Evil

To investigate the collar more, I positioned and slid the collar off after observing four screws unevenly placed on the lens barrel. I noticed some metal shavings... I blew off the shavings and removed the collar curious if perhaps the screws had loosened (easy fix). And was surprised that they were all tight. It seems that the screws rub against the slots that allow the collar to slip into place, making the barrel difficult to spin, and anything but smooth. The felt fabric that lines the collar seems to be intact and still has some memory (spring) left in it. Is this just the way it is designed, or is something amiss? Do the replacement collar/feet correct this lens barrel rotation issue?

Best regards,
Tom

Posted: Sat Jul 17, 2010 3:34 pm

As per suggestion, I have tried dry silicon graphite (Mr. ZIP Extra Fine Graphite) applied to the heads of the screws. There is no noticeable lens collar rotational improvement. I did notice more metal shavings when I removed the collar from the lens barrel. I noted on the ID of the collar where the screws have been grinding as indicated by removed paint and some minimal scoring.

I have located another replacement collar made by RRS (Really Right Stuff) model number LC-A10. Their site is not easy to navigate and there may be other "gems" that are buried. I believe they need a "Misc." item link in the navigation bar, and item list. I located it by accident when looking at lens plates. After clicking the obscure "Next" for the 3rd time, you will locate a Replacement collar for the 300mm f/4 AF-S. In any case, if you think that $159.00 USD is expensive for the Kirk like I did, then do not bother looking at the RRS plate, it is $195.00 USD. However, I may be persuaded if I am unable to correct the issue(s) at hand on my own. Wink