Odd issue with older Micro lens

Hi everyone,

 

This might be a longshot, but I wanted to know if anyone had some ideas about an odd error with a lens of mine. This is an older 105mm 2.8 micro lens, screw-driven AF, with a large toggle switch on the lens barrel for switching between AF and M focusing. It's really a great lens for my purposes. The issue is this: if the lens focuses to infinity (or almost infinity), the reported f/stop becomes f/32 (regardless of what I have it set to) and the AF stops completely. The only way to fix either issue is to set the lens to manual focusing and pull back to less than infinity. Then the lens jumps back to normal use.

 

It's kind of annoying to work with because any time the lens searches too far towards infinity, the AF shuts down. Any thoughts to what is causing this? Thanks.

Edited May 28, 2022 by daniel_johnson|6

I'm not familiar with this AF-S(?) 105 2.8 lens in particular but based on the AF/M switch mentioned without research I'd assume it's a AF-S lens, correct? However, I did have the same experience with the 28-70 2.8 AF-S lens myself years ago, e.g. lens stops AF function as soon as it reaches 10ish ft-mark towards to infinite and causes camera body hang/freeze at same time then had to switch to manual and restart camera to continue, VERY annoyance. Tried to "fix" it myself in risk and couldn't find anything wrong by naked eyes inside of lens assembly. After all decided to depart it in a condition of as-is for parts or repair, never looked back. Sooner or later, learned from online that there tends to be some AF or electronic issues with old AF-S lenses (not confirmed) but just my own stories for your references, and good luck.

If screw driven, I assume is an AF or AFD lens, they have a coupling/decoupling A-M switch ring. AFS lenses are ultrasonic.

I don`t have this lens, but I think it is obviously damaged. Maybe the barrel get stuck, or there is a contact problem at the end for whatever the reason... time for CLA (don't know if it is worth it these days; anyway, if it works at manual focus, I'd use it this way... probably much better to achieve accurate focusing).

Edited May 31, 2022 by jose_angel

It sure sounds like an electronic issue. Are you enough of a long-time Nikon user to have a manual focus body? If I were to experience this issue I'd want to see if the lens was at least still mechanically sound by running it through apertures on the B setting and looking to see if the blades closed down incrementally.

 

Eric Sande

I have the AFD version of this lens and it does not behave this way. I suspect an internal problem. Given the likely cost of repair, though, I would second the idea of finding if it does work ok in some mode, as well as making sure all contacts are good, and maybe resign to using it as is if possible.

I still own one such lens. Mine is just AF, but the AF-D is almost identical. The OP’s lens is malfunctioning.