60/f2.8 micro

[xaviermacau]

After some months of use, I noticed that the 60/f2.8 micro changes aperture while focusing. I work on A (aperture preferred) and set to 2.8 but as I focus the aperture changes to higher number and when I dial back, I could not reach the 2.8. Had to switch the camera off, take off the lens and snap it again and turn on the camera to get the aperture.
Went to the shop where I purchased the lens, they sent it back to Nikon service. After a month, it came back with the same problem. Is this normal or is there something wrong?
Thanks for your opinion.

 

[Beezle]

I believe that is perfectly normal.

 

[nfoto]

It is not only "normal", it is by design. The aperture indicated is what is technically called "effective" aperture. This will indeed change when the lens is focused closer, because the added extension will cause a light loss. All this is by the way described in the lens' manual. At the closest distance I think f/2.8 (infinity) will be f/5 (1:1) indicating that the light loss is 1.7 stops (numbers from memory, but they are about correct if not spot on).

The shop in which you purchased the lens should have known better and prevented a completely unwarranted return to the Nikon service.

 

[Johnbotu]

I wonder the same thing now I know.

Thanks tonfoto

John

 

[xaviermacau]

Thank you for all the input. In fact I could have asked before I went to the supplier but all happened when I mounted the lens on the D2x that came about a month ago and I tried on all the lenses I had hastedly.
Thank you very much Beezle and Bjorn.